Performance information

• Multiscale analysis on microstructural changes in hardened cement paste dried under different relative humidity levels: A comparison with cement paste containing water-dispersible polyurethane ether compound　　　　　　　　　　　　　　　
  Shingo Asamoto; Keisuke Takahashi; Naoki Sakamoto; Tokio Sampei; Kunio Matsui
  Cement and Concrete Research, Volume：194, First page：107896, Last page：107896, Aug. 2025, [Reviewed], [Lead, Corresponding]
  Elsevier BV, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconres.2025.107896
  DOI ID：10.1016/j.cemconres.2025.107896, ISSN：0008-8846
• Mesoscale simulation of cracking and shrinking during drying under coupled effect of environmental factors using 3D RBSM　　　　　　　　　　　　　　　
  Haoyu Wang; Jie Luo; Shingo Asamoto; Yuya Sakai; Kohei Nagai
  Case Studies in Construction Materials, Volume：22, Jul. 2025, [Reviewed]
  Accurately predicting and evaluating durability issues in reinforced concrete (RC) structures presents a significant challenge, particularly in the case of cracking induced by drying shrinkage. Experimental investigations of drying-related cracking problems are characterized by lengthy experimental cycles, the need to consider multiple influences, and a high degree of randomness, rendering the challenge inadequately addressed in the form of comprehensive experimental analyses. This kind of cracking arises from the uneven distribution of moisture within concrete, where water evaporation and loss through voids and cracks result in volume shrinkage and crack formation. The entire process has a prolonged duration and is significantly influenced by stochastic environmental factors, making the prediction and evaluation of shrinkage strains and of structural performance after cracking challenging. In this study, a 3D Rigid Body Spring Model (RBSM) is employed to simulate the process of concrete drying. An input strain model that takes account of various environmental factors is established and validated against previously reported experiments. Totally, four kinds of environmental factors are considered. The validation results indicate that, at the material level, the model effectively simulates the shrinkage behavior of concrete under the coupled effect of multiple environmental factors. The influence of individual environmental factors on the drying process is clearly distinguished. Additionally, the effects of multiple environmental factors on the drying process are discussed.
  Scientific journal
  DOI：https://doi.org/10.1016/j.cscm.2025.e04317
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85216077911&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85216077911&origin=inward
  DOI ID：10.1016/j.cscm.2025.e04317, ISSN：2214-5095, SCOPUS ID：85216077911
• Strength changes associated with water transport in unsaturated tuff during drying　　　　　　　　　　　　　　　
  Yota Togashi; Haruhiko Kotabe; Masahiko Osada; Shingo Asamoto; Ken Hatakeyama
  International Journal of Rock Mechanics and Mining Sciences, Volume：186, Feb. 2025, [Reviewed]
  The impact of water content on the strength of sedimentary rocks is a critical area of research, particularly in the contexts of disaster prevention and the construction of underground structures. Despite numerous factors being identified as contributors to the strength variations in sedimentary rocks caused by water content, a comprehensive understanding remains elusive. Moreover, only a limited number of cases have been discussed on strength changes in these rocks during water transport processes. In this study, one-dimensional water transport experiments were conducted during the drying process on Neogene tuff samples from Japan. The experiments focused on the unsaturated permeation of the porous media and analyzed the variations in advection and diffusion terms relative to saturation changes at multiple points. During the drying process, water transfer occurred primarily through diffusion, although advection was significant in the early stages to equilibrate the hydraulic head at the center of the specimen. Furthermore, the same tuff samples, with adjusted water content during the drying process, were tested using Brazilian and uniaxial compression methods to examine the variations in strength properties owing to the variations in water content. By comparing these results with the water transport data, we observed that significant alterations in strength occurred after the convergence of the advection term. It was shown for the first time that the decrease in strength of tuff occurs only during the water diffusion phase. These results are expected to be applied to more accurate evaluation of rock mass stability and advanced numerical analysis.
  Scientific journal
  DOI：https://doi.org/10.1016/j.ijrmms.2024.105984
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85211155098&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85211155098&origin=inward
  DOI ID：10.1016/j.ijrmms.2024.105984, ISSN：1365-1609, SCOPUS ID：85211155098
• Experimental study on flexural behaviour of DEF–ASR-affected prestressed concrete beams　　　　　　　　　　　　　　　
  Hakmana Vidana Arachchige Nuwan Sanjeewa; Ayumu Matsumoto; Shingo Asamoto; Renaud Pierre Martin; François Toutlemonde
  Engineering Structures, Volume：319, Nov. 2024, [Reviewed], [Corresponding]
  When concrete is exposed to high temperatures during initial hydration, delayed ettringite formation (DEF) may occur and cause expansion, with consequences similar to that of the alkali-silica reaction (ASR). This study investigated the structural performance of prestressed concrete (PC) beams exhibiting expansion owing to DEF and the combined effects of DEF and ASR. In both cases, concrete cylinders were cast to determine the expansion, compressive strength, and dynamic elastic modulus at different expansion levels. The compressive strength and Young's modulus of the plain concrete specimens were significantly reduced with large free expansion, which caused map cracking on the surface. Because of the restraining effects of the reinforcement and prestressing load, the expansion of the PC beams was anisotropic, with more longitudinal cracks. The Young's modulus determined from stiffness of the cross-section of the DEF and ASR–DEF-affected beams at a low load level without bending cracking decreased moderately (22 % for DEF and 30 % for ASR–DEF beams) as compared to that of the non-reactive companion beam. The load capacities of DEF and ASR–DEF-damaged beams, even with many cracks, were reduced by 16 % and 23 %, respectively, compared to those of the non-reactive beam. Though the compressive strength of deteriorated plain concrete decreased significantly, less compressive strength reduction in concrete of DEF and ASR–DEF-damaged beams owing to confinement resulted in the lesser load capacity reduction in beams.
  Scientific journal
  DOI：https://doi.org/10.1016/j.engstruct.2024.118835
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85202173746&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85202173746&origin=inward
  DOI ID：10.1016/j.engstruct.2024.118835, ISSN：0141-0296, eISSN：1873-7323, SCOPUS ID：85202173746
• Why sorption hysteresis in tobermorite is limited　　　　　　　　　　　　　　　
  Tulio Honorio; Farid Benboudjema; Shingo Asamoto
  Microporous and Mesoporous Materials, Sep. 2024, [Reviewed]
  Scientific journal
  DOI：https://doi.org/10.1016/j.micromeso.2024.113205
  DOI ID：10.1016/j.micromeso.2024.113205, ORCID：161483910
• Conditions of DEF Development in Various Climatic Conditions: Laboratory and Field Investigation　　　　　　　　　　　　　　　
  Renaud-Pierre Martin; Shingo Asamoto; Yuichiro Kawabata; Célia Khetib; François Toutlemonde
  May 2024, [Reviewed]
  DOI：https://doi.org/10.1007/978-3-031-59349-9_64
  DOI ID：10.1007/978-3-031-59349-9_64, ORCID：159020298
• Mechanical Properties of ASR/DEF Damaged Concrete Under External Restraints　　　　　　　　　　　　　　　
  Hakmana Vidana Arachchige Nuwan Sanjeewa; Shingo Asamoto
  May 2024, [Reviewed], [Corresponding]
  DOI：https://doi.org/10.1007/978-3-031-59349-9_24
  DOI ID：10.1007/978-3-031-59349-9_24, ORCID：159020296
• Effect of Cement and Exposed Environment Differences on DEF Expansion: Joint Investigation Using Constituents from Japan and France　　　　　　　　　　　　　　　
  Shingo Asamoto; Azusa Izumi; Yuichiro Kawabata; Celia Khetib; Renaud-Pierre Martin; François Toutlemonde; Takumi Shimomura; Jun Tomiyama
  May 2024, [Reviewed], [Corresponding]
  DOI：https://doi.org/10.1007/978-3-031-59419-9_18
  DOI ID：10.1007/978-3-031-59419-9_18, ORCID：158951656
• Interaction of ASR and DEF in Determining the Cause of Cracks in Prestressed Sleepers in India　　　　　　　　　　　　　　　
  Yoko Ando; Shinichi Hirono; Shingo Asamoto; Kohei Nagai
  RILEM Bookseries, Volume：50, First page：301, Last page：308, May 2024, [Reviewed]
  In prestressed sleepers used in India, longitudinally extending and map-shaped cracks occurred at many service points 6–9 years after manufacture. Polarizing microscopy and electron microscopy of thin sections made from the concrete showed that the gneissic aggregate had a distinct ASR. Other gaps at the aggregate-cement paste interface and reticulated cracks, which were different from the extension of the ASR cracks, were also observed. The filling of ettringite within the gaps and cracks confirmed that DEF had occurred. It was therefore concluded that the cause of deterioration of the Indian sleepers was combined ASR and DEF deterioration. The very high alkali content of the cement used in India, coupled with the hot and humid environment, may have contributed to the development of ASR and DEF. In addition, an estimation of whether ASR or DEF occurred prior to the ASR or DEF was made from microscopic texture observations. The results showed that both were considered to have occurred prior to each other.
  In book
  DOI：https://doi.org/10.1007/978-3-031-59349-9_35
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85194576403&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85194576403&origin=inward
  DOI ID：10.1007/978-3-031-59349-9_35, ISSN：2211-0844, eISSN：2211-0852, SCOPUS ID：85194576403
• A review of mechanical properties of deteriorated concrete due to delayed ettringite formation and its influence on the structural behavior of reinforced concrete members　　　　　　　　　　　　　　　
  Hakmana Vidana Arachchige Nuwan Sanjeewa; Shingo Asamoto
  Construction and Building Materials, Apr. 2024, [Reviewed], [Corresponding]
  Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2024.135795
  DOI ID：10.1016/j.conbuildmat.2024.135795, ORCID：155335572
• Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part II: Bond Performance of Reinforced Concrete Affected by DEF Expansion
  Taito Miura; Misato Fujishima; Yuichiro Kawabata; Stéphane Multon; Renaud-Pierre Martin; Naoshi Ueda; Yuya Takahashi; Shingo Asamoto; Jean-Francois Seignol
  Journal of Advanced Concrete Technology, Volume：21, Number：11, First page：869, Last page：888, Nov. 2023, [Reviewed]
  Japan Concrete Institute, Scientific journal
  DOI：https://doi.org/10.3151/jact.21.869
  DOI ID：10.3151/jact.21.869, ISSN：1346-8014, eISSN：1347-3913
• Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part I: The Role of Bond on Expansive Behavior of Concrete
  Yuichiro Kawabata; Taito Miura; Misato Fujishima; Naoshi Ueda; Yuya Takahashi; Shingo Asamoto; Stéphane Multon; Renaud-Pierre Martin; Jean-Francois Seignol
  Journal of Advanced Concrete Technology, Volume：21, Number：11, First page：851, Last page：868, Nov. 2023, [Reviewed]
  Japan Concrete Institute, Scientific journal
  DOI：https://doi.org/10.3151/jact.21.851
  DOI ID：10.3151/jact.21.851, ISSN：1346-8014, eISSN：1347-3913
• Standardized models for cracking due to restraint of imposed strains—The state of the art　　　　　　　　　　　　　　　
  Agnieszka Jędrzejewska; Mariusz Zych; Fragkoulis Kanavaris; Fangjie Chen; Shintaro Ito; Jean Michel Torrenti; Dirk Schlicke; Shingo Asamoto; Miguel Azenha
  Structural Concrete, Aug. 2023, [Reviewed]
  Scientific journal
  DOI：https://doi.org/10.1002/suco.202200301
  DOI ID：10.1002/suco.202200301, ORCID：127448739
• Length Change and Water Uptake Characteristics of Synthesized Calcium Silicate Hydrates
  Shingo Asamoto; Rintaro Koyama; Kunio Matsui; Keisuke Takahashi
  International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures, First page：773, Last page：783, Jun. 2023, [Reviewed], [Corresponding]
  Springer Nature Switzerland, In book
  DOI：https://doi.org/10.1007/978-3-031-33187-9_71
  DOI ID：10.1007/978-3-031-33187-9_71, ISSN：2211-0844, eISSN：2211-0852
• Effect of High Temperature at Early Age and Mineral Additives on Drying Shrinkage of Concrete with Blast Furnace Slag Cement　　　　　　　　　　　　　　　
  Tatsuya Usui; Shingo Asamoto; Shintaro Miyamoto
  Jun. 2023, [Reviewed]
  DOI：https://doi.org/10.1007/978-3-031-33211-1_90
  DOI ID：10.1007/978-3-031-33211-1_90, ORCID：136660035
• Effect of high temperature at early ages on drying shrinkage and creep of concrete focusing on microcracking damage　　　　　　　　　　　　　　　
  Shingo Asamoto; Isao Kurashige; Pang-Jo Chun
  Materials and Structures, Volume：56, Number：4, May 2023, [Reviewed], [Corresponding]
  This study aimed to examine the influence of high temperature, at early ages, on the drying shrinkage and creep of concrete focusing on the microcracking at the interfacial transition zone between coarse aggregates and mortar. Concrete was cast with different cement and coarse aggregates and cured at 65 degrees C at early ages. Drying shrinkage and creep tests were conducted, and the dynamic modulus of elasticity and air permeability were measured. Image analysis was used to detect microcracking by impregnating fluorescent epoxy resin in concrete. The drying shrinkage and creep of concrete at high temperature increased when ground granulated blast furnace slag (GGBFS) was added, whereas they reduced when ordinary Portland cement was added. At high temperatures, the dynamic modulus of elasticity was reduced, and the air permeability increased for concrete with GGBFS. Microcracking was observed around the coarse aggregates in the concrete with GGBFS and a high-temperature history, according to the microscopic observation and the image analysis. The microcracking may be caused by the difference in the coefficient of thermal expansion between limestone coarse aggregate and the mortar with GGBFS and the large drying shrinkage of cement paste with GGBFS. Microcracking in the concrete with GGBFS and a high-temperature history might propagate and vertically close under sustained load with drying, increasing the creep although the creep of the cement paste with GGBFS was decreased owing to the high temperature.
  SPRINGER, English, Scientific journal
  DOI：https://doi.org/10.1617/s11527-023-02156-2
  DOI ID：10.1617/s11527-023-02156-2, ISSN：1359-5997, eISSN：1871-6873, ORCID：132404762, Web of Science ID：WOS:000962747100001
• INVESTIGATION INTO WATER UPTAKE CHARACTERISTICS OF HARDENED CEMENT PASTE BASED ON DIFFUSION EQUATION　　　　　　　　　　　　　　　
  ASAMOTO Shingo; SHIREN Ryota; MATSUI Kunio; TAKAHASHI Keisuke
  Cement Science and Concrete Technology, Volume：76, Number：1, First page：290, Last page：298, Mar. 2023, [Reviewed], [Corresponding]
  The previous studies have reported that the water absorption amount with time can be proportional to the fourth root of absorption time. In this study, the water uptake characteristics of hardened cement paste was studied from a viewpoint of fourth root of uptake time. The one bottom surface of cement paste specimen was exposed to liquid water after drying equilibrium at 20, 40 and 105℃. The amount of water absorption was proportional to the fourth root of time as reported in the previous studies. In the case of drying at 105℃, the relationship was bilinear, which suggests that the water can penetrate into relatively large capillary pores and then fine gel pores as two processes. The model to apply different diffusion equations to the assumed capillary and gel pores can reproduce the water uptake behavior of cement paste dried at 105℃ when the constant diffusivities are used for each pore. The diffusion equations were applied to divided pore diameters, respectively when the simple pore distribution was assumed. It was found that the model to use constant large and small diffusivities according to threshold of pore diameter can represent the bilinear relationship between the water absorption amount and fourth root of time rather than the model to use the decreasing diffusivity with decreasing pore diameter.
  Japan Cement Association, Japanese
  DOI：https://doi.org/10.14250/cement.76.290
  DOI ID：10.14250/cement.76.290, ISSN：0916-3182, eISSN：2187-3313
• Estimator for generalization performance of machine learning model trained by biased data collected from multiple references　　　　　　　　　　　　　　　
  Yuriko Okazaki; Shinichiro Okazaki; Shingo Asamoto; Toru Yamaji; Minoru Ishige
  Computer-Aided Civil and Infrastructure Engineering, First page：early view, Mar. 2023, [Reviewed]
  Wiley, English, Scientific journal
  DOI：https://doi.org/10.1111/mice.12992
  DOI ID：10.1111/mice.12992, ISSN：1093-9687, ORCID：132635878
• Experimental study on mortar with the addition of hydrophobic silicone oil for water absorption, strength, and shrinkage　　　　　　　　　　　　　　　
  Yao Luan; Shingo Asamoto
  Construction and Building Materials, Volume：367, First page：130323, Last page：130323, Feb. 2023, [Reviewed], [Last]
  Elsevier {BV}, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2023.130323
  DOI ID：10.1016/j.conbuildmat.2023.130323, ISSN：0950-0618, ORCID：132635845
• Mesoscale simulation of compression-induced cracking and failure of ASR-damaged concrete with stirrup confinement　　　　　　　　　　　　　　　
  Jie Luo; Shingo Asamoto; Kohei Nagai
  Engineering Fracture Mechanics, Volume：277, First page：108977, Last page：108977, Jan. 2023, [Reviewed]
  The alkali-silica reaction (ASR) is a durability concern that can lead to expansion and cracking of concrete structures. ASR damage affects the physical characteristics of the concrete itself, although the load-carrying capacity of an RC structure may be maintained because the reinforcement continues to confine the core concrete. However, if the combined effect of expansion damage and external loading were to result in reinforcement rupture, this would prejudice the safety of a structure. To study this phenomenon, the discrete numerical simulation method 3D RBSM is used to carry out a parametric study of the compressive failure of concrete with three ASR damage levels under confinement. Stirrups with normal yield strength and with elastic behavior are investigated. The ASR expansion and cracking behavior for concrete with different confinement scenarios are presented and discussed. Following that, the compressive failure of concrete with ASR damage and the effect of stirrup confinement are studied. The simulated stress–strain relationships for cases without ASR damage are well fitted by a theoretical prediction model. As for elastic modulus and compressive strength, it tends to decrease with increasing ASR expansion whatever the confinement conditions. For models confined by stirrups, the degradation of compressive strength is delayed. Visualizations of internal stress, concrete crack propagation and stirrup strain development are obtained from the simulations and these are discussed. It is found that the confinement effect of elastic stirrups is greater than that of stirrups with normal yield strength. Further, the strain distribution on inner and outer surfaces of stirrups which is hard to be monitored in experiments is extracted. Stress concentrations arise at the inner radius of the stirrup bends, which is consistent with observations of real structures and could lead to rupture at these locations.
  Elsevier {BV}, English, Scientific journal
  DOI：https://doi.org/10.1016/j.engfracmech.2022.108977
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85143591881&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85143591881&origin=inward
  DOI ID：10.1016/j.engfracmech.2022.108977, ISSN：0013-7944, ORCID：132635940, SCOPUS ID：85143591881
• An analytical investigation of bond deterioration between rebar and ASR/DEF-damaged concrete with and without stirrup confinement using 3D RBSM　　　　　　　　　　　　　　　
  Jie Luo; Shingo Asamoto; Kohei Nagai
  Construction and Building Materials, Volume：351, First page：128923, Last page：128923, Oct. 2022, [Reviewed]
  The bond performance between rebar and concrete is essential for the safety of RC structures. There is a need for research on bond deterioration due to the alkali-silica reaction (ASR) and delayed ettringite formation (DEF) damage which affects real structures. In this paper, a parametric study is conducted to quantitatively study the effect of slight-to-severe ASR/DEF damage in the presence of stirrup confinement on the pullout behavior between concrete and reinforcement using three-dimensional rigid body spring model (3D RBSM) simulation. It is found through the simulation that the bond stress in ASR damaged cases increases when ASR expansion before pullout is small and then decreases as the damage level rises, while the bond stress in DEF damaged cases keeps decreasing from the beginning. Besides, higher stirrup confinement effectively mitigates bond deterioration in both ASR and DEF damaged cases when damage is serious. More importantly, stress development and crack propagation during the expansion stage and the pullout stage are visualized. Interface cracking condition varies according to the damage type (ASR or DEF) and the level of stirrup confinement due to different cracking mechanisms. However, the tendency for the number of cracks in the concrete to increase, which reflects the overall damage level in ASR and DEF damaged cases, is similar, resulting in a similar trend for bond stress to decrease.
  Elsevier BV, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2022.128923
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85136613293&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85136613293&origin=inward
  DOI ID：10.1016/j.conbuildmat.2022.128923, ISSN：0950-0618, ORCID：132635972, SCOPUS ID：85136613293
• Mesoscopic simulation of crack propagation and bond behavior in ASR damaged concrete with internal/external restraint by 3D RBSM　　　　　　　　　　　　　　　
  Jie Luo; Yi Wang; Shingo Asamoto; Kohei Nagai
  Cement and Concrete Composites, Volume：129, First page：104488, Last page：104488, May 2022, [Reviewed]
  One of the most serious serviceability concerns for reinforced concrete (RC) structures is expansion and cracking resulting from the alkali-silica reaction (ASR), which has a negative effect on material properties as well as the bond between reinforcement and surrounding concrete. In a typical RC member, ASR induced concrete expansion and cracking are restrained by internal reinforcement as well as the boundary conditions. The mechanism is complex and difficult to understand through experimental study, so predicting the residual capacity of a damaged RC structure is not easy. In this study, the authors use a 3D Rigid Body Spring Model (RBSM) comprising mortar, aggregate and steel elements and which is able to simulate ASR expansion in reinforced concrete. To study the complex interactions among multiple parameters and quantify the effect of ASR damage on structural behavior, previously reported experiments on ASR induced expansion under internal and external restraint are simulated, along with experiments on pullout behavior after ASR expansion. The effect of restraints on macroscopic ASR expansion is well modeled in each case, and how the development of internal stresses and concrete cracking influenced by the restraint can be explained from the simulations. The simulations enable discussion of the number of ASR-induced cracks and the internal stress condition in various cases. The peak bond strength of concrete with different ASR damage levels, as reported in pullout experiments, is predicted accurately and the load-displacement curves of ASR damaged concrete are discussed.
  Elsevier BV, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconcomp.2022.104488
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85126468039&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85126468039&origin=inward
  DOI ID：10.1016/j.cemconcomp.2022.104488, ISSN：0958-9465, ORCID：109731917, SCOPUS ID：85126468039
• Investigation of the mechanical behaviour of concrete with severe delayed ettringite formation expansion focusing on internal damage propagation under various compressive loading patterns　　　　　　　　　　　　　　　
  Nirmal Raj Joshi; Ayumu Matsumoto; Shingo Asamoto; Taito Miura; Yuichiro Kawabata
  Cement and Concrete Composites, Volume：128, First page：104433, Last page：104433, Apr. 2022, [Reviewed], [Corresponding]
  Elsevier BV, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconcomp.2022.104433
  DOI ID：10.1016/j.cemconcomp.2022.104433, ISSN：0958-9465, ORCID：107474875
• Multiscale structural changes and drying shrinkage of Portland cement pastes: effects of a fatty-alcohol-based shrinkage reducing agent
  Keisuke Takahashi; Kunio Matsui; Shingo Asamoto; Naoki Sakamoto
  Materials and Structures, Volume：55, Number：2, Mar. 2022, [Reviewed]
  Springer Science and Business Media {LLC}, English, Scientific journal
  DOI：https://doi.org/10.1617/s11527-022-01889-w
  DOI ID：10.1617/s11527-022-01889-w, ISSN：1359-5997, eISSN：1871-6873, ORCID：132636076
• Microstructural properties and water penetration resistance of cementitious binder combined with water-dispersible polyurethane　　　　　　　　　　　　　　　
  Keisuke Takahashi; Shingo Asamoto; Makoto Babazono; Yoshinori Matsuda
  Cement and Concrete Composites, Volume：125, First page：104326, Last page：104326, Jan. 2022, [Reviewed]
  Elsevier {BV}, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconcomp.2021.104326
  DOI ID：10.1016/j.cemconcomp.2021.104326, ORCID：102575102
• The Cover Depth Effect on Corrosion-Induced Deterioration of Reinforced Concrete Focusing on Water Penetration: Field Survey and Laboratory Study
  Shingo Asamoto; Junya Sato; Shinichiro Okazaki; Pang-jo Chun; Raktipong Sahamitmongkol; Giang Hoang Nguyen
  Materials, Volume：14, Number：13, First page：3478, Last page：3478, Jun. 2021, [Reviewed], [Lead, Corresponding]
  Reinforced concrete bridges were visually surveyed in Japan, Thailand, and Vietnam to study the deterioration caused by internal steel corrosion under different climates, focusing on the concrete cover depth. Spalling or cracking arising from corrosion is likely where water is supplied. According to prior studies and our surveys, a concrete cover depth of more than 40 mm was found to prevent spalling, regardless of environmental conditions and structure age. Because water supply at steel is a key corrosion factor, it was hypothesised that under natural conditions, the water penetration in concrete would remain at a depth of approximately 40 mm. Our laboratory study examined water penetration under drying and wetting conditions. The results also suggested that under periodic rainfall conditions, the threshold of water penetration was not exceeded. The numerical study indicated maximum moisture evaporation to facilitate oxygen diffusion occurred at a depth of approximately 30–40 mm unless the concrete was exposed to continuous drying for more than one month. It was experimentally and numerically concluded that an adequate cover depth of greater than 40 mm could inhibit moisture and oxygen penetration at the steel, which supported the survey findings of cover depth effect on a high resistance to corrosion-induced deterioration despite an increase in service life.
  MDPI AG, English, Scientific journal
  DOI：https://doi.org/10.3390/ma14133478
  DOI ID：10.3390/ma14133478, ISSN：1996-1944, eISSN：1996-1944, ORCID：99902223
• Present status and issues of control technology for cracking of mass concrete in Japan
  Toshiaki Mizobuchi; Shingo Asamoto
  RILEM Technical Letters, Volume：6, First page：25, Last page：35, May 2021, [Reviewed]
  This paper presents the current state of the control technology for cracks caused by heat generation due to the hydration of cement during construction in Japan. For the prediction analysis for thermal cracking of mass concrete, this paper presents the CP method that was developed for the first time in the world, the thermal cracking probability, the simple evaluation method that can predict and estimate the thermal cracking without performing complicated analysis and the evaluation method for expansive materials using the mechanical energy conservation hypothesis. In addition, issues are introduced for the next revision of the guidelines.
  Rilem Publications {SARL}, Scientific journal
  DOI：https://doi.org/10.21809/rilemtechlett.2021.137
  DOI ID：10.21809/rilemtechlett.2021.137, ISSN：2518-0231, eISSN：2518-0231, ORCID：99902171
• Time-Dependent Deformation of a Concrete Arch Dam in Thailand - Numerical Study on Effect of Alkali Silica Reaction on Deflection of Arch
  Nirmal R. Joshi; Thanadet Sriprasong; Shingo Asamoto; Pakawat Sancharoen
  Journal of Advanced Concrete Technology, Volume：19, Number：3, First page：181, Last page：195, Mar. 2021, [Reviewed], [Corresponding]
  Japan Concrete Institute, English, Scientific journal
  DOI：https://doi.org/10.3151/jact.19.181
  DOI ID：10.3151/jact.19.181, ISSN：1346-8014, eISSN：1347-3913, ORCID：99902249
• DEF膨張が生じたコンクリートの圧縮応力下での内部損傷進行の検討　　　　　　　　　　　　　　　
  松本歩; JOSHI Nirmal Raj; 浅本晋吾; 川端雄一郎
  Volume：43, 2021, [Reviewed]
  ISSN：2424-0281, J-Global ID：202102230064430839
• PRACTICAL PREDICTION MODEL VERIFICATION AND REGRESSION ANALYSIS BY MACHINE LEARNING USING CONCRETE DRYING SHRINKAGE DATABASE　　　　　　　　　　　　　　　
  石毛成; 浅本晋吾; 岡崎百合子; 岡崎慎一郎
  AI・データサイエンス論文集(Web), Volume：2, Number：J2, 2021, [Reviewed], [Corresponding]
  ISSN：2435-9262, J-Global ID：202202263621386215
• Undersampling Strategy for Machine-learned Deterioration Regression Model in Concrete Bridges　　　　　　　　　　　　　　　
  Yuriko Okazaki; Shinichiro Okazaki; Shingo Asamoto; Pang-jo Chun
  Journal of Advanced Concrete Technology, Volume：18, Number：12, First page：753, Last page：766, Dec. 2020, [Reviewed]
  Japan Concrete Institute, English, Scientific journal
  DOI：https://doi.org/10.3151/jact.18.753
  DOI ID：10.3151/jact.18.753, ISSN：1346-8014, ORCID：99902260
• STUDY ON THE COMBINED ALKALI SILICA REACTION AND DELAYED ETTRINGITE FORMATION　　　　　　　　　　　　　　　
  Thanadet Sriprasong
  International Journal of GEOMATE, Volume：19, Number：75, Nov. 2020, [Reviewed], [Corresponding]
  International Journal of Geomate, Scientific journal
  DOI：https://doi.org/10.21660/2020.75.38051
  DOI ID：10.21660/2020.75.38051, ISSN：2186-2982, ORCID：99902394
• Applicability of machine learning to a crack model in concrete bridges　　　　　　　　　　　　　　　
  Yuriko Okazaki; Shinichiro Okazaki; Shingo Asamoto; Pang jo Chun
  Computer-Aided Civil and Infrastructure Engineering, Volume：35, Number：8, First page：775, Last page：792, Aug. 2020, [Reviewed]
  © 2020 Computer-Aided Civil and Infrastructure Engineering The growing demand for a more efficient maintenance of concrete bridges requires a model that tracks the deterioration of each bridge based on inspection data. Although it has been expected that machine learning could be applied to this problem, inspection data sparsely distributed over time are not suitable for machine learning in contrast to the continuous big data usually targeted. This study applies machine learning to a regression model of crack formation and propagation using inspection data to confirm the applicability. It includes the selection of the optimal algorithm, development of the model based on a novel methodology, and factor analysis using the model. Accordingly, the model was constructed by Gaussian process regression and it could appropriately extract the differences in the progress of crack damage due to multiple influential factors. The results demonstrate the excellent applicability of machine learning even to sparse data.
  WILEY, English, Scientific journal
  DOI：https://doi.org/10.1111/mice.12532
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85078732704&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85078732704&origin=inward
  DOI ID：10.1111/mice.12532, ISSN：1093-9687, eISSN：1467-8667, ORCID：69306406, SCOPUS ID：85078732704, Web of Science ID：WOS:000508563800001
• A mesoscale discrete model for mechanical performance of concrete damaged by coupled ASR and DEF　　　　　　　　　　　　　　　
  Yi Wang; Punyawut Jiradilok; Kohei Nagai; Shingo Asamoto
  Engineering Fracture Mechanics, Volume：232, First page：107055, Last page：107055, Jun. 2020, [Reviewed]
  © 2020 Elsevier Ltd Real concrete structures can suffer simultaneously from the alkali-silica reaction (ASR) and delayed ettringite formation (DEF), resulting in expansion of the concrete and surface map cracking. This damage can lead to serious durability problems. The respective effects of ASR and DEF have been studied, but the cracking behavior of concrete when they act together remains unclear. In this study, a three-dimensional rigid body spring model (3D RBSM) is used to simulate the cracking and mechanical property degradation of concrete under coupled ASR and DEF. A parametric study is conducted to understand various combinations of ASR and DEF. In line with previous studies by the authors on independent ASR/DEF damage, expansions caused by ASR and DEF are, respectively, introduced as strains at the mortar-aggregate interface and in mortar elements. Due to a confinement effect, specimens subjected to coupled expansion may suffer less expansion or cracking than when only one of the degradations is acting. The model clearly visualizes the cracking process and stress development as the degree of coupled expansion increases. More importantly, based on the simulated results, the interactions of the two types of expansion are revealed by correlating the degradation in mechanical properties with internal cracking behavior. Further, the confinement effect arising on application of the second type of expansion is quantitatively examined. While there is no significant change in stiffness, compressive strength in some cases increases with expansion as larger cracks close up under the confinement effect. This kind of investigation of coupled effects is difficult to quantitatively analyze through experimentation, but this work demonstrates that it is possible using RBSM simulations.
  PERGAMON-ELSEVIER SCIENCE LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.engfracmech.2020.107055
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85084063351&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85084063351&origin=inward
  DOI ID：10.1016/j.engfracmech.2020.107055, ISSN：0013-7944, eISSN：1873-7315, ORCID：99902298, SCOPUS ID：85084063351, Web of Science ID：WOS:000536482400007
• Regression analysis of concrete shrinkage and creep laboratory data by machine learning　　　　　　　　　　　　　　　
  浅本晋吾; 岡崎百合子; 岡崎慎一郎; CHUN Pang-jo
  AI・データサイエンス論文集(Web), Volume：1, Number：J1, 2020, [Reviewed], [Lead, Corresponding]
  ISSN：2435-9262, J-Global ID：202102260048305615
• 高級アルコール系収縮低減剤が極初期材齢の細孔構造に及ぼす影響と乾燥収縮の抑制との関係　　　　　　　　　　　　　　　
  高橋恵輔; 松井久仁雄; 浅本晋吾
  Volume：42, 2020, [Reviewed]
  ISSN：2424-0281, J-Global ID：202002232799474938
• Evaluation of Autoclaved Aerated Concrete Fines for Removal of Cd(II) and Pb(II) from Wastewater　　　　　　　　　　　　　　　
  G. M.P. Kumara; Ken Kawamoto; Takeshi Saito; Shoichiro Hamamoto; Shingo Asamoto
  Journal of Environmental Engineering (United States), Volume：145, Number：11, Nov. 2019, [Reviewed]
  © 2019 American Society of Civil Engineers. Along with the increase of autoclaved aerated concrete (AAC) production, the amount of scrap waste (industrial by-products) is increasing. AAC waste, however, is not yet being fully reused or recycled and is discarded without any treatment in most developing countries. In this study, AAC fines were tested as effective and economic adsorbents for the removal of Cd2+ and Pb2+ from wastewater. A series of batch adsorption experiments were carried out using AAC with three different particle sizes (<0.105, 0.105-2, and 2-4.75 mm) to examine effects of the particle size, initial metal concentration (Ci), initial pH (pHi), ionic strength, contact time, and competitive metals. For comparing the adsorption characteristics and capacities, crushed concrete fines and a fine sand were also used. Results showed that the adsorption kinetic data were well fitted to the pseudo-second-order kinetics model for all tested materials. Pb2+ adsorption was independent of pHi and ionic strength for AAC fines, whereas Cd2+ adsorption varied depending on pHi and decreased drastically at pHi≤7. Based on the results from adsorption isotherms, the Freundlich model fitted well (R2>0.90) to the data for 300≤Ci≤5,000 mg/L, whereas the Langmuir model was applicable (R2>0.99) to the data for Ci≤2,000 mg/L. The maximum adsorption capacity of each particle size of AAC exhibited almost the same adsorption capacity for Cd2+ (15 mg/g) and Pb2+ (>250 mg/g), which are similar to or higher than the values of other types of adsorbents in previous studies. The metal removal by AAC is controlled mainly by ion exchange, surface complexation, and surface precipitation. In particular, the Ca2+ ion exchange on the hydrated adsorbent surface is the dominant adsorption mechanism at the early stage of adsorption. The selectivity sequence of metal adsorptions became Pb2+>Cu2+>Ni2+>Cd2+>Zn2+ for AAC, and the existence of Pb2+ and Cu2+ in wastewater highly impeded the Cd2+ adsorption onto AAC fines.
  ASCE-AMER SOC CIVIL ENGINEERS, English, Scientific journal
  DOI：https://doi.org/10.1061/(ASCE)EE.1943-7870.0001597
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85071765777&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85071765777&origin=inward
  DOI ID：10.1061/(ASCE)EE.1943-7870.0001597, ISSN：0733-9372, eISSN：1943-7870, ORCID：62552645, SCOPUS ID：85071765777, Web of Science ID：WOS:000486511200004
• Expansive cracking and compressive failure simulations of ASR and DEF damaged concrete using a mesoscale discrete model　　　　　　　　　　　　　　　
  Yi Wang; Yushi Meng; Punyawut Jiradilok; Koji Matsumoto; Kohei Nagai; Shingo Asamoto
  Cement and Concrete Composites, Volume：104, Nov. 2019, [Reviewed]
  © 2019 Elsevier Ltd Internal stresses induced by the alkali silica reaction (ASR) and delayed ettringite formation (DEF) can cause cracking and degrade the mechanical properties of concrete, but the relationship between these phenomena remains unclear. In this study, crack patterns and the loss of compressive strength and elastic modulus of concrete after ASR and DEF expansion are simulated at the mesoscale using a three-dimensional Rigid Body Spring Model (3D RBSM). Concrete expansions induced by ASR and DEF are introduced in the model by applying initial strain on the springs of interfacial transition zone (ITZ) and mortar elements as damage history respectively. After verifying the model with single aggregate, further analysis of differences in concrete cracking due to ASR and DEF damage is carried out. The effect of the percentage of reactive aggregate is studied in the cases of ASR damage, while different intensified expansion areas are considered in the case of DEF. The simulated losses of mechanical properties of the concrete are compared with the experimental results and good agreement is obtained. It is found that the loss of mechanical properties is dominated by internal cracks rather than the surface crack pattern. Compressive strength is highly dependent on the development of large cracks while elastic modulus is closely related to the total number of cracked faces. More importantly, regardless of the intensified expansion area, the mechanical properties are consistent with expansive cracking damage.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconcomp.2019.103404
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85071619029&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85071619029&origin=inward
  DOI ID：10.1016/j.cemconcomp.2019.103404, ISSN：0958-9465, eISSN：1873-393X, ORCID：62552290, SCOPUS ID：85071619029, Web of Science ID：WOS:000501649500069
• コンクリート橋梁のひび割れ損傷に対する回帰モデルに適した機械学習アルゴリズムの選択　　　　　　　　　　　　　　　
  岡崎 百合子; 岡崎 慎一郎; 浅本 晋吾; 全 邦釘
  Volume：41, Number：1, First page：581, Last page：586, Sep. 2019, [Reviewed]
  Japanese
  ISSN：2424-0281, J-Global ID：201902227102153897
• Concrete cold joint formation in hot weather conditions　　　　　　　　　　　　　　　
  Gayan Buddhika Illangakoon; Shingo Asamoto; Anura Nanayakkara; Lam Nguyen Trong
  Construction and Building Materials, Volume：209, First page：406, Last page：415, Jun. 2019, [Reviewed], [Corresponding]
  © 2019 Elsevier Ltd The performance of a concrete structure can be greatly affected by the presence of a cold joint: it causes deterioration of steel reinforcement in concrete, strength reduction, and destruction of the aesthetic appearance of the concrete surface. Cold joint formation becomes more likely in hot weather conditions due to the rapid setting behaviour of the concrete. The objective of this study was to examine the effect of the ambient temperatures on cold joint formation relating to the penetration resistance. Cold joint formation was evaluated by determining the flexural strength of a cold-jointed concrete beam. Fresh concrete with initial temperatures of 25 °C was tested under the ambient temperature conditions of 25 °C and 45 °C. The experimental results show that the cold joint forms when the delay in placement between two consecutive layers is less than the conventional initial setting time of concrete, measured according to ASTM C403 (i.e., 3.5 N/mm 2 penetration resistance). It was found that cold joints form when the penetration resistance is greater than 0.5 N/mm 2 and this penetration resistance is independent of the ambient temperature.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2019.03.093
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85062859933&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85062859933&origin=inward
  DOI ID：10.1016/j.conbuildmat.2019.03.093, ISSN：0950-0618, eISSN：1879-0526, ORCID：55348635, SCOPUS ID：85062859933, Web of Science ID：WOS:000468713000038
• Study on Strength and Characteristics of Cement Paste for Well Exposed to 200 °C　　　　　　　　　　　　　　　
  浅本晋吾; 塚原美晴; 伊藤貴康; 松井久仁雄
  材料, Volume：68, Number：6, 2019, [Reviewed], [Lead, Corresponding]
  ISSN：0514-5163, J-Global ID：201902285089283014
• Effects of fatty alcohol-based shrinkage reducing agents on early-age shrinkage under high temperature conditions　　　　　　　　　　　　　　　
  Keisuke Takahashi; Shingo Asamoto; Mari Kobayashi; Thomas Bier
  Journal of Advanced Concrete Technology, Volume：17, Number：11, First page：648, Last page：658, 2019, [Reviewed]
  © 2019 Japan Concrete Institute. Arid and tropical climates are prone to the occurrence of drying shrinkage cracking at early ages. Shrinkage reducing agents (SRAs) are often used to mitigate drying shrinkage, whose key action on the reduction of early-age shrinkage was seen to be a reduction of capillary tension. However, the roles of SRAs on reduction of shrinkage that have been reported, throw doubt on the idea that SRAs work solely via capillary tension. In order to clarify the mechanisms of early-age shrinkage in the presence of SRAs, the effects of fatty alcohol-based SRAs on shrinkage strain, capillary pore pressure and crack area of cement-based mortars at early ages were investigated. Our results demonstrated clearly that capillary tension does not directly correlate with shrinkage strain at early ages in the presence of SRAs, even under the same profiles of evaporation and hydration. We interpreted the actions of SRAs on early-age shrinkage as follows: SRA micelles adsorb onto hydrates and/or exist in pores, and form the hydrate matrix with incorporated SRA micelles. The matrix could mitigate the capillary tension as stress absorbers, and thereby shrinkage and crack area are reduced. The concept of the matrix could be experimentally demonstrated by the changes in shear creep.
  JAPAN CONCRETE INST, English, Scientific journal
  DOI：https://doi.org/10.3151/jact.17.648
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85077467498&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85077467498&origin=inward
  DOI ID：10.3151/jact.17.648, ISSN：1346-8014, eISSN：1347-3913, ORCID：69306426, SCOPUS ID：85077467498, Web of Science ID：WOS:000500240800004
• Sorption isotherm and length change behavior of autoclaved aerated concrete　　　　　　　　　　　　　　　
  Lam Nguyen Trong; Shingo Asamoto; Kunio Matsui
  Cement and Concrete Composites, Volume：94, First page：136, Last page：144, Nov. 2018, [Reviewed], [Corresponding]
  © 2018 Elsevier Ltd We conducted an experimental study on the sorption isotherm and length change behavior of autoclaved aerated concrete (AAC) in both desorption and adsorption processes. Three types of AAC with different bulk densities were used to study the length change mechanism. The experimental results show that the expansion of AAC during the adsorption process is mostly larger than the shrinkage in the first desorption process even though the water content in the adsorption process is lower. Interestingly, a clear expansion in the desorption process in a range of relative humidity (RH) from about 90% to 65% and a significant difference in the length change strain between the desorption and adsorption processes (shrinkage hysteresis) at high RH are observed. Based on these experimental results, we propose a model to represent the mechanism of the hygral length change of AAC, taking into account the changes in surface free energy of the solid surface and capillary tension. The model reasonably explains the significantly different length change behaviors of AACs with different pore structures.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconcomp.2018.09.003
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85053374181&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85053374181&origin=inward
  DOI ID：10.1016/j.cemconcomp.2018.09.003, ISSN：0958-9465, eISSN：1873-393X, ORCID：48086278, SCOPUS ID：85053374181, Web of Science ID：WOS:000451493000014
• Microstructure and shrinkage behavior of Autoclaved Aerated Concrete (AAC) -Comparison of Vietnamese and Japanese AACs-　　　　　　　　　　　　　　　
  Nguyen Trong Lam; Shingo Asamoto; Kunio Matsui
  Journal of Advanced Concrete Technology, Volume：16, Number：8, First page：333, Last page：342, Aug. 2018, [Reviewed], [Corresponding]
  Copyright © 2018 Japan Concrete Institute. We investigated the microstructure and shrinkage behavior of autoclaved aerated concrete (AAC) from several manufacturers in Vietnam comparing with Japanese AAC. Three types of Vietnamese AAC and one type of Japanese AAC were used for powder X-ray diffraction, scanning electron microscopy, mercury intrusion porosimetry, and shrinkage tests. The experimental results show that the main hydration products of AAC that used fly ash as silica materials is semi-crystalline calcium silicate hydrate, while the ones of others are tobermorite; but the tobermorite crystals of AACs from some manufacturers in Vietnam are disordered structures and lack of interlocking among tobermorite crystals. The pore size distribution of all Vietnamese AAC are single peak, whereas Japanese AAC is bimodal. The pore distribution characteristics of AACs significantly influenced their shrinkage behavior and the shrinkage of Vietnamese AAC is higher than that of Japanese AAC at intermediate relative humidity (RH). The capillary tension is the principle shrinkage mechanism for AAC materials at high RH (above about 65%) to cause local minimum shrinkage of Japanese AAC at high RHs, while the change in surface free energy is dominant at low RH conditions.
  JAPAN CONCRETE INST, English, Scientific journal
  DOI：https://doi.org/10.3151/jact.16.333
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85052108041&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85052108041&origin=inward
  DOI ID：10.3151/jact.16.333, ISSN：1346-8014, eISSN：1347-3913, ORCID：62552516, SCOPUS ID：85052108041, Web of Science ID：WOS:000444853300002
• インドで発生したPC枕木のひび割れの原因究明とASRおよびDEFの相互作用　　　　　　　　　　　　　　　
  安藤陽子; 片山哲哉; 浅本晋吾; 長井宏平
  Volume：40, 2018, [Reviewed]
  ISSN：2424-0281, J-Global ID：201802244599310725
• Study on internal water repellency and mechanical characteristics of cementitious materials with the addition of hydrophobic agent　　　　　　　　　　　　　　　
  Asamoto Shingo; Furuta Haruka; Luan Yao; Yoneda Taiju
  Concrete Research and Technology, Volume：29, Number：0, First page：11, Last page：19, 2018, [Reviewed], [Lead, Corresponding]
  

  In order to inhibit water penetration into concrete, hydrophobic surface impregnation is generally used to protect concrete, but there is concern that water repellency may decrease greatly when cracks occur. This study aims to develop an internal hydrophobic cementitious material by mixing several hydrophobic agents. Two mixing methods of the agents, direct mixing and sand spraying, were carried out. It was found that mortar with sand sprayed with silicone-based agent had a relatively high contact angle and hydrophobicity under wetting and drying cycles even if cracks occurred, although compressive strength decreased to some extent. Further, mortar with the addition of an alkyl-modified siloxane agent could greatly inhibit the water penetration after partial drying, and drying shrinkage was also found to be smaller than that of normal mortar.

  
  Japan Concrete Institute, Japanese
  DOI：https://doi.org/10.3151/crt.29.11
  DOI ID：10.3151/crt.29.11, ISSN：1340-4733, CiNii Articles ID：130006309080
• Reviews on the applicability of construction and demolition waste as low-cost adsorbents to remove-heavy metals in wastewater　　　　　　　　　　　　　　　
  G. M.P. Kumara; Takashi Saito; Shingo Asamoto; Ken Kawamoto
  International Journal of GEOMATE, Volume：14, Number：42, First page：44, Last page：51, 2018, [Reviewed]
  © Int. J. of GEOMATE. Removal of heavy metals from wastewater is of special concern due to the persistence of heavy metals in the environment. The industrial discharge of heavy metals adversely affects soil and water resources, aquatic organisms, and ecosystem integrity. In addition, high concentrations of heavy metals are detected in solid waste landfill leachate in many developing countries due to non-segregated waste dumping. At present, various kinds of adsorbents such as activated carbon, biomass resources, geomaterials, and industrial waste products are used to treat heavy metal-contaminated water. However, the use of construction and demolition waste (CDW) and its recycled materials to treat heavy metal-contaminated water has not been fully examined. Because the generation of CDW is increasing due to rapid urbanization and a high demand for construction, the wise use of CDW and its recycled materials is necessary. This paper reviews journal articles published from 2004 to 2016 that studied the applicability of low-cost CDW adsorbents to remove heavy metals from wastewater. In particu-lar, it summarizes results on using CDW and recycled materials such as cement, concrete, and brick compared to those from various other adsorbents such as biosorbents, geomaterials, and their industrial products. The poten-tial applicability of CDW and its recycled materials as heavy-metal adsorbents was examined based on a com-parison table listing material properties, test conditions, and measured adsorption properties.
  GEOMATE INT SOC, English, Scientific journal
  DOI：https://doi.org/10.21660/2018.42.7148
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85040908556&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85040908556&origin=inward
  DOI ID：10.21660/2018.42.7148, ISSN：2186-2982, eISSN：2186-2990, ORCID：62552537, SCOPUS ID：85040908556, Web of Science ID：WOS:000429528700008
• CRACK PROPERGATION MODEL OF CONCRETE BRIDGES IN SHIKOKU BASED DATA DRIVEN APPROACH　　　　　　　　　　　　　　　
  岡崎百合子; 岡崎慎一郎; CHUN Pang-jo; 浅本晋吾; 大窪和明
  土木学会論文集 F4(建設マネジメント)(Web), Volume：74, Number：4, First page：I_107, Last page：I_118, 2018, [Reviewed]
  Japanese
  ISSN：2185-6605, J-Global ID：201902262620823617
• データ駆動型アプローチによるコンクリート橋梁のひび割れ発生・進展の回帰モデルの構築および要因分析　　　　　　　　　　　　　　　
  岡崎 百合子; 岡崎 慎一郎; 全 邦釘; 浅本 晋吾
  Volume：40, Number：2, First page：1381, Last page：1386, 2018, [Reviewed]
  Japanese
  ISSN：2424-0281, J-Global ID：201802269745598532
• Effect of carbonate ions on delayed ettringite formation　　　　　　　　　　　　　　　
  Shingo Asamoto; Kohki Murano; Isao Kurashige; Anura Nanayakkara
  Construction and Building Materials, Volume：147, First page：221, Last page：226, Aug. 2017, [Reviewed], [Lead, Corresponding]
  © 2017 Elsevier Ltd The effect of carbonate ions gradually dissolved from limestone powder on delayed ettringite formation (DEF) and the inhibition of DEF by fly ash were examined. To accelerate DEF expansion, 3% SO3 by cement weight was added and the specimens were exposed to a temperature of 90 °C at an early age (1 day) and then stored under tap water at 20 °C. In addition, the specimens submerged in a solution with a high carbonate ion concentration (0.15 mol/L) after exposure at 90 °C were also studied to explicitly investigate the effect of carbonate ions on DEF. The limestone powder in the cement accelerated DEF expansion in samples with 3% SO3 addition that were exposed to temperatures over 90 °C at an early age. Specimens in the solution containing carbonate ions showed greater swelling than those in tap water. This indicates that the carbonate ions in the pore solution can promote DEF. Fly ash inhibited DEF even in cement with 3% SO3 addition and during storage in the solution with a high carbonate ion concentration.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2017.04.107
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85018904156&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85018904156&origin=inward
  DOI ID：10.1016/j.conbuildmat.2017.04.107, ISSN：0950-0618, eISSN：1879-0526, ORCID：32263208, SCOPUS ID：85018904156, Web of Science ID：WOS:000403854100022
• Investigation on possible causes of expansion damages in concrete – a case study of sleepers in Indian Railways　　　　　　　　　　　　　　　
  Anupam Awasthi; Koji Matsumoto; Kohei Nagai; Shingo Asamoto; Seishi Goto
  Volume：3, Number：1, First page：49, Last page：66, Jul. 2017, [Reviewed]
  Indian Railways uses factory made pre-tensioned pre-stressed concrete sleepers for its track. These sleepers start cracking after 6-9 years of their manufacturing in many areas of the Indian Railways. For the investigation of the premature cracking of sleepers, different categories of samples namely “Severely damaged”, “Moderately damaged”, and “Undamaged” are collected from different locations of Indian Rail- ways. These samples are analyzed under Scanning Electron Microscope (SEM) and Energy Dispersive Spec- troscopy (EDS). SEM images reveal that there is large ettringite deposition at the interfaces of aggregate and paste in case of “Severely damaged” and “Moderately damaged” sleepers, which could be a cause of delete- rious expansion and subsequent cracking, whereas the interfaces of “Undamaged” sleepers were found to be intact. High temperature experienced by these sleepers in form of steam curing during their production in factories may lead to Delayed Ettringite Formation (DEF) and subsequent expansion and cracking. Tempera- ture recorded in the concrete sleeper plant during steaming of the sleepers reveals that the temperature inside concrete exceeds 80°C, which is a critical temperature for the occurrence of damage due to DEF in future. Also, stress bench method of production of concrete sleepers, used in Indian Railways for older concrete sleeper plant, poses some structural deficiency which adversely affects the temperature of curing. Thus, DEF could be the possible cause of premature cracking of sleepers in Indian Railways.
  DOI：https://doi.org/10.18702/acf.2017.06.3.1.49
  DOI：https://doi.org/10.1016/j.engfracmech.2020.107055_references_DOI_AqmJ6XWu5iIgqxa3LaaUI7BmtcO
  DOI ID：10.18702/acf.2017.06.3.1.49, ISSN：2465-7964, eISSN：2465-7972
• 各種撥水材を活用したセメント系材料の内部撥水性の評価と材料特性の検討　　　　　　　　　　　　　　　
  古田悠佳; 欒堯; 浅本晋吾; 米田大樹
  Volume：38, 2016, [Reviewed]
  ISSN：2424-0281, J-Global ID：201702231789691792
• 遅延エトリンガイト生成に及ぼす炭酸イオンの影響に関する検討　　　　　　　　　　　　　　　
  浅本晋吾; 村野耕基; 蔵重勲; NANAYAKKARA Anura
  Volume：38, 2016, [Reviewed], [Lead]
  ISSN：2424-0281, J-Global ID：201702269523539606
• 200°Cに曝露された坑井セメントペーストの物性変化に基づく強度特性の検討　　　　　　　　　　　　　　　
  塚原美晴; 浅本晋吾
  Volume：38, 2016, [Reviewed]
  ISSN：2424-0281, J-Global ID：201702239664170841
• Study on Pore Structure and Air Permeability Variations by Carbonation of Cementitious Materials Exposed to Supercritical CO₂　　　　　　　　　　　　　　　
  ASAMOTO Shingo; HIRAI Ryosuke
  Journal of the Society of Materials Science, Japan, Volume：65, Number：2, First page：155, Last page：161, 2016, [Reviewed], [Lead, Corresponding]
  CCS (Carbon dioxide Capture and Storage) projects have been focused on as one of state-of-art technologies to prevent the CO₂ emission in the atmosphere. In a project, the CO₂ collected from factories is injected into the geological reservoir at deep underground through well and stored in the reservoir. It is expected that the well will have gradual degradations due to high temperature, high pressure and high concentration CO₂ at deep underground. The process of the degradations should be investigated to prevent from leaking the CO₂ through the well. In this study, the variation of pore structure and air permeability by the carbonation of the hardened cement paste exposed to the supercritical CO₂ under water, salt water and sealed condition was examined focusing on the carbonation progress. The pore structure of small sample (diameter 4mm and height 4 mm) became denser at 1 day of exposure all cases because of the precipitation of CaCO₃ in capillary pores while the carbonation of C-S-H occurred at 7 days to make pores coarse in the case of supercritical CO₂ in water. It was experimentally found that the slight carbonation makes pores denser and leads to the reduction of the air permeability. The hardened cement paste using oil well cement with fly ash had denser pore structure to make permeability smaller than that using only oil well cement. It is attributed to Pozzolanic reaction of fly ash at high temperature. Thus, it was suggested that fly ash has a potential to apply to the CCS well from a view point of the prevention of CO₂ gas leakage.
  The Society of Materials Science, Japan, Japanese
  DOI：https://doi.org/10.2472/jsms.65.155
  DOI ID：10.2472/jsms.65.155, ISSN：0514-5163, J-Global ID：201602213756571410, CiNii Articles ID：130005126270, CiNii Books ID：AN00096175
• Effect of creep induction at an early age on subsequent prestress loss and structural response of prestressed concrete beam　　　　　　　　　　　　　　　
  Shingo Asamoto; Kyosuke Kato; Takeshi Maki
  Construction and Building Materials, Volume：70, First page：158, Last page：164, Nov. 2014, [Reviewed], [Lead, Corresponding]
  The authors investigated a technique to inhibit subsequent prestress loss in a concrete beam by effective creep induction at an early age, and examined the structural performances of beams with the creep at an early age. Consistent experimental results suggested that a more progressive creep induced by a higher first prestressing force or under an elevated temperature (45 °C) at an early age was likely to reduce the prestress loss after another prestressing at seven days of age. The creep tended to increase the compressive strength and Young's modulus of the concrete, and the tensile strength was not decreased when the sustained stress was within the elastic range. The flexural behaviour of a prestressed concrete beam with the creep at an early age was observed to be almost the same as that of a beam without the creep, although the maximum flexural crack width was slightly increased by the early age creep. It was found that the shear crack propagation was more progressive when the creep was significantly accelerated at an early age under severe conditions that applied a high sustained stress beyond the elastic range or at the elevated temperature. It was thus concluded that a larger creep induction at an early age impeded subsequent prestress loss in concrete beams more significantly, although its acceleration under the above severe conditions may lead to reduction of the structural performance. © 2014 Elsevier Ltd. All rights reserved.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2014.07.028
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84906546016&origin=inward
  DOI ID：10.1016/j.conbuildmat.2014.07.028, ISSN：0950-0618, eISSN：1879-0526, ORCID：25696227, SCOPUS ID：84906546016, Web of Science ID：WOS:000343337500018
• 混合セメントを用いたRC部材の持続荷重下の曲げひび割れ進展に対する養生日数,乾湿繰り返しの影響　　　　　　　　　　　　　　　
  浅本晋吾; 横井太一; 平林雅也; 小林薫
  Volume：36, 2014, [Reviewed], [Lead]
  ISSN：2424-0281, J-Global ID：201402203840611736
• INFLUENCE OF HIGH TEMPRATURE HISTORY ON MECHANICAL PROPERTIES OF CEMENTITIOUS MATERIALS WITH LOW WATER-TO-BINDER RATIO　　　　　　　　　　　　　　　
  MURANO Koki; ASAMOTO Shingo; KURASHIGE Isao; MINATO Daisuke
  Cement Science and Concrete Technology, Volume：68, Number：1, First page：140, Last page：147, 2014, [Reviewed]
  In this study, the effect of high temperature history arising from the hydration heat on mechanical properties of concrete with low water-to-binder ratio was experimentally investigated. Cement paste and mortar specimens using Ordinary Portland cement, slag cement and fly ash cement were exposed to constant temperatures（20℃ and 80℃）and fictitious temperature rise at early age due to the hydration reaction under sealing conditions soon after casting. At an age of 28 days, mercury intrusion porosimetry test and compressive strength test were carried out for each specimen to compare different temperature histories and cement types. The compressive strength of cement paste with mineral admixture at 28 days of age was increased when it was exposed high temperature. It is attributed to the promotions of latent hydraulic reactions of slag and pozzolanic reaction of fly ash under high temperature. The mercury intrusion porosimetry test revealed denser porosity of cement paste exposed to high temperature than that of cement paste cured at 20℃. The compressive strength of mortar cured at 80℃ was reduced in all cement cases. It is speculated that the continuous high temperature exposure may make interfacial transition zone between cement paste and aggregate damaged due to the self-desiccation under high temperature. In addition, the compressive strength of mortar with high temperature rise at an early age was reduced at an age of 91 ages comparing to the strength at an age of 28 days in all cases. It is suggested that the strength of mortar with low water-to-binder ratio may be gradually decreased when it has a high temperature history at an early age.
  Japan Cement Association, Japanese
  DOI：https://doi.org/10.14250/cement.68.140
  DOI ID：10.14250/cement.68.140, ISSN：0916-3182, CiNii Articles ID：130005129354
• Well integrity assessment for CO2 injection: A numerical case study on thermo-mechanical behavior in downhole CO2 environments　　　　　　　　　　　　　　　
  Shingo Asamoto; Yvi Le Guen; Olivier Poupard; Bruno Capra
  Engineering Computations (Swansea, Wales), Volume：30, Number：6, First page：842, Last page：853, Aug. 2013, [Reviewed], [Lead, Corresponding]
  Purpose - In the carbon dioxide capture and storage (CCS) project, the integrity of CO2 injection wells plays a vital role in the long-term safety of CO2 storage. The authors aim to practically investigate possible CO2 leakage of a CO2 injection well section during the injection operation and shut-in by the thermomechanical FEM simulation. The application of numerical simulation to the CO2 injection well deep underground is the first step that will help in the quantitative evaluation of the mechanical risks. Design/methodology/approach - The injection of CO2 at a temperature different from those of the well and the surrounding geological formation is likely to cause different thermal deformations of constitutive well materials. This could lead to cement cracking and microannuli openings at the interfaces of different materials such as casing/cement and cement/rock. In this paper, the possibility and order of magnitude of cement cracking and microannuli creation in the cross section of the well are assessed from a numerical case study within a classical thermomechanical finite element model framework. Findings - The possibility of compressive failure and tensile cracking in the cement of the studied wells due to CO2 injection is small unless a large casing eccentricity or an initial defect in the cement is present. Some microannuli openings are generated at interfaces cement/casing and/or cement/rock during the CO2 injection because of different thermal shrinkage of each material. However, the width is not important enough to cause significant CO2 leakage under the studied conditions. The use of "flexible" cement especially developed for oil well applications could mitigate the risk of cement cracking during CO2 injection. Originality/value - Numerous experimental studies on the chemical deterioration of the cement under severe conditions have been carried out. On the other hand, only a few investigations have focused on the mechanical behavior under thermal/pressure changes related to CO2 injection. In this paper, the quantitative analysis to investigate cement cracking and microannuli formation is achieved to help in the identification of possible mechanical defects to cause CO2 leakage. In addition, the discussion about the risk of the possible casing eccentricity and the application of flexible cement in the oil and gas field to CO2 injection well could be practically useful. © Emerald Group Publishing Limited.
  EMERALD GROUP PUBLISHING LTD, English, International conference proceedings
  DOI：https://doi.org/10.1108/EC-05-2012-0117
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84883398285&origin=inward
  DOI ID：10.1108/EC-05-2012-0117, ISSN：0264-4401, eISSN：1758-7077, ORCID：20393214, SCOPUS ID：84883398285, Web of Science ID：WOS:000324897000007
• 超臨界二酸化炭素に曝露されたセメント硬化体の炭酸化進行および空隙構造変化に関する研究　　　　　　　　　　　　　　　
  平井遼介; 磯崎光; 浅本晋吾
  Volume：35, 2013, [Reviewed]
  ISSN：2424-0281, J-Global ID：201302276411769127
• STUDY ON VOLUMETRIC CHANGE MECHANISM OF HARDENED CEMENT PASTE BASED ON LIQUID CHARACTERISTICS IN FINE PORES　　　　　　　　　　　　　　　
  ASAMOTO Shingo; MATSUI Kunio; KATO Kyosuke
  Cement Science and Concrete Technology, Volume：67, Number：1, First page：195, Last page：202, 2013, [Reviewed], [Lead]
  In this study, the authors investigate the volumetric change of hardened cement paste when the dried specimens under various conditions are soaked in different polar or non-polar liquids. The objective is to comprehend the dominant phenomena to cause the shrinkage of the cement paste based on liquid characteristics. When the oven dried specimens are submerged in various liquids other than water, the shrinkage due to the oven dry is hardly recovered while the shrinkage of the specimens is almost recovered by submerging in water. This could be because the adsorption of the liquids to cement paste is much smaller than that of water and could have little reduction of the solid surface energy of cement paste. The large shrinkage is observed after moist-cured specimens are soaked in polar solvents which are dissolved in water. It could be attributed to the decrease of disjoining pressure and increase of solid surface energy due to the absorption of liquid water and adsorbed water in fine pores and C-S-H gel. The shrinkage of partially dried specimens is recovered soon after soaking in both polar and non-polar liquids. It is speculated that the decrease of capillary tension or the increase of disjoining pressure cause the immediate recovery of the shrinkage.
  Japan Cement Association, Japanese
  DOI：https://doi.org/10.14250/cement.67.195
  DOI ID：10.14250/cement.67.195, ISSN：0916-3182, J-Global ID：201402221054628070, CiNii Articles ID：130004745753
• Characteristic of Chloride Ion Diffusion in Mortar Mixed with Ion-Exchange Resin　　　　　　　　　　　　　　　
  Sanada Osamu; Mutsuyoshi Hiroshi; Asamoto Shingo; Inoue Nobuhito
  Concrete Research and Technology, Volume：24, Number：3, First page：123, Last page：134, 2013, [Reviewed]
  Recently, a number of concrete structures constructed several decades earlier are showing significant degradation, especially in coastal areas. For the effective repair and reinforcement of such structures, the development of high performance repairing material is required. Meanwhile, ion exchange resin has traditionally been used to remove impurities such as chloride in the process of cleaning industrial wastewater and manufacturing pure water. In this study, for the purpose of removing the chloride in deteriorated concrete structures, the application of ion exchange resin to repairing material is investigated. Firstly, the effect of ion exchange resin on the adsorption of chloride ion in mortar is examined by chemical analysis. The diffusion of chloride in mortar with ion exchange resin is experimentally and numerically studied. Finally, it is experimentally verified that the chloride in mortar is removed by inverse diffusion due to the ion exchange resin.
  Japan Concrete Institute, Japanese
  DOI：https://doi.org/10.3151/crt.24.123
  DOI ID：10.3151/crt.24.123, ISSN：1340-4733, CiNii Articles ID：130003378375
• INVESTIGATION INTO EFFECT OF CURING TEMPEARTURE AND MINERAL ADMIXTURES ON SHRINKAGE CRACKING RESISTANCE BY ADVANCED SHRINKAGE RESTRAIN TEST　　　　　　　　　　　　　　　
  ASAMOTO Shingo; KATO Masanori; MAKI Takeshi; KURASHIGE Isao
  Cement Science and Concrete Technology, Volume：66, Number：1, First page：95, Last page：102, 2012, [Reviewed], [Lead]
  The authors consistently investigate the shrinkage cracking resistance of mortar containing blast furnace slag or fly ash, based on the proposed experimental method：it can intentionally induce a shrinkage crack in the drying area of small mortar specimens under restrained condition. In order to clarify the dominant material properties in shrinkage cracking, the water curing at 20℃ and the extreme condition of water curing at 60℃ were provided for each specimen to have the different pore structures. The shrinkage cracking resistance of mortar with blast furnace slag is likely to be reduced than that of mortar without mineral admixture or with fly ash as indicated in previous studies. The mortar cured in water at 60℃ without mineral admixture has higher shrinkage cracking resistance than the one cured in water at 20℃ has, while it takes a slightly long or not much different time to cause the shrinkage cracks on the mortar cured in water at 60℃ with slag compared to the one cured in water at 20℃. On the other hand, the stress was greatly decreased when the mortar with fly ash were dried after curing under water at 60℃. It is deduced that the dense pore structure of mortar with fly ash due to water curing at 60℃ could cause the shrinkage gradient from surface to internal and lead to micro-crack generation on the surface due to the internal confinement. It is concluded that the micro-crack could decrease the tensile strength and result in the reduction of shrinkage cracking resistance.
  Japan Cement Association, Japanese
  DOI：https://doi.org/10.14250/cement.66.95
  DOI ID：10.14250/cement.66.95, ISSN：0916-3182, J-Global ID：201302249296221786, CiNii Articles ID：130004574772
• Well Integrity: Modeling of Thermo-Mechanical Behavior and Gas Migration along Wells-Application to Ketzin Injection Well　　　　　　　　　　　　　　　
  Le Guen Yvi; Asamoto Shingo; Houdu Emmanuel; Poupard Olivier
  Energy Procedia, Volume：23, First page：462, Last page：471, 2012
  Elsevier BV, Scientific journal
  DOI：https://doi.org/10.1016/j.egypro.2012.06.042
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84897135551&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84897135551&origin=inward
  DOI ID：10.1016/j.egypro.2012.06.042, ISSN：1876-6102, ORCID：20393216, SCOPUS ID：84897135551, Web of Science ID：WOS:000314116000046
• Study on effects of solar radiation and rain on shrinkage, shrinkage cracking and creep of concrete　　　　　　　　　　　　　　　
  Shingo Asamoto; Ayumu Ohtsuka; Yuta Kuwahara; Chikako Miura
  Cement and Concrete Research, Volume：41, Number：6, First page：590, Last page：601, Jun. 2011, [Reviewed], [Lead, Corresponding]
  In this paper, the effects of actual environmental actions on shrinkage, creep and shrinkage cracking of concrete are studied comprehensively. Prismatic specimens of plain concrete were exposed to three sets of artificial outdoor conditions with or without solar radiation and rain to examine the shrinkage. For the purpose of studying shrinkage cracking behavior, prismatic concrete specimens with reinforcing steel were also subjected to the above conditions at the same time. The shrinkage behavior is described focusing on the effects of solar radiation and rain based on the moisture loss. The significant environment actions to induce shrinkage cracks are investigated from viewpoints of the amount of the shrinkage and the tensile strength. Finally, specific compressive creep behavior according to solar radiation and rainfall is discussed. It is found that rain can greatly inhibit the progresses of concrete shrinkage and creep while solar radiation is likely to promote shrinkage cracking and creep. © 2011 Elsevier Ltd. All rights reserved.
  PERGAMON-ELSEVIER SCIENCE LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.cemconres.2011.03.003
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79955476911&origin=inward
  DOI ID：10.1016/j.cemconres.2011.03.003, ISSN：0008-8846, ORCID：20393217, SCOPUS ID：79955476911, Web of Science ID：WOS:000291298000003
• 浸漬熱と吸着測定によるセメントペーストと軽量気泡コンクリートの細孔構造の比較　　　　　　　　　　　　　　　
  松井久仁雄; 浅本晋吾
  Volume：33, 2011, [Reviewed]
  ISSN：2424-0281, J-Global ID：201102203569685069
• 養生・乾燥温度に依存する混和材混入モルタルの収縮特性に関する研究　　　　　　　　　　　　　　　
  辻貴大; 加藤優典; 浅本晋吾; 蔵重勲
  Volume：33, 2011, [Reviewed]
  ISSN：2424-0281, J-Global ID：201102250877915227
• Structural behavior of hybrid FRP composite I-beam　　　　　　　　　　　　　　　
  Nguyen Duc Hai; Hiroshi Mutsuyoshi; Shingo Asamoto; Takahiro Matsui
  Construction and Building Materials, Volume：24, Number：6, First page：956, Last page：969, Jun. 2010, [Reviewed]
  This paper presents the structural behavior of an innovative hybrid Fiber Reinforced Polymers (FRP) beam consisting of carbon/glass fibers and vinyl-ester resin. The advanced feature of this hybridization is the optimum use of carbon and glass fibers in the flanges to maximize structural performance while reducing the overall cost by using only glass fibers in the web section. A series of beam tests were conducted under four-point bending varying ratio of flange to web width (bf/bw) and volume content of carbon and glass fiber in the flanges. Experimental investigations revealed that the ratio of flange to web width of hybrid FRP I-shaped beams plays an important role in their structural behavior. Small flange beams (bf/bw = 0.43) showed stable and linear behavior under bending moment and failed in a brittle manner by delamination of the compressive flange at the interfacial layers while wide flange beams (bf/bw = 1.13) exhibited unstable and nonlinear behavior in the buckling and post-buckling region leading to delamination failure of the compressive flange. The experimental and analytical results discussed in this paper emphasize on the best composition of carbon and glass fibers for the optimum design of such hybrid beams. It is found that the maximum strength of hybrid FRP beams can be obtained with the volume content of carbon fiber to be 25-33%. Furthermore, the results of this study show the potential of applying hybrid FRP beams for bridge components. © 2009 Elsevier Ltd. All rights reserved.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.conbuildmat.2009.11.022
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77949570810&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77949570810&origin=inward
  DOI ID：10.1016/j.conbuildmat.2009.11.022, ISSN：0950-0618, ORCID：20393218, SCOPUS ID：77949570810, Web of Science ID：WOS:000277781000012
• Study on Shrinkage and Shrinkage Cracking Behavior of Concrete under Actual Environmental Condition　　　　　　　　　　　　　　　
  ASAMOTO Shingo; OHTSUKA Ayumu; MIURA Chikako; KUWAHARA Yuta
  Concrete Research and Technology, Volume：21, Number：2, First page：35, Last page：43, May 2010, [Reviewed], [Lead]
  In this study, the influences of both rain and solar radiation on shrinkage and shrinkage cracking under actual environmental conditions are investigated. Moisture loss, shrinkage, shrinkage cracks were measured under three different outdoor conditions in order to examine the effects of rain and solar radiation separately. It was experimentally found that the penetration of rain into concrete greatly inhibits moisture loss, shrinkage and shrinkage cracking. While the solar radiation accelerates the evaporation of moisture in concrete, shrinkage of plain concrete cannot increase so much due to the drying but shrinkage cracking can be significantly promoted by solar radiation. It is concluded that the actual environmental actions such as rain and solar radiation should be taken into account in design in order to appropriately predict the deterioration of concrete structure.
  Japan Concrete Institute, Japanese
  DOI：https://doi.org/10.3151/crt.21.2_35
  DOI ID：10.3151/crt.21.2_35, ISSN：1340-4733, J-Global ID：201002272452659207, CiNii Articles ID：10026450743, CiNii Books ID：AN1053282X
• 固体表面に吸着する液体特性に依存するセメント硬化体の体積変化　　　　　　　　　　　　　　　
  浅本晋吾; 宮腰良太; 辻貴大; 松井久仁雄
  Volume：32, 2010, [Reviewed], [Lead]
  ISSN：2424-0281, J-Global ID：201002240177955195
• 高炉スラグ微粉末を用いたモルタル供試体の水分逸散と収縮特性に与える養生及び乾燥温度履歴の影響　　　　　　　　　　　　　　　
  加藤優典; 辻貴大; 浅本晋吾
  Volume：32, 2010, [Reviewed]
  ISSN：2424-0281, J-Global ID：201002299303714659
• 超高強度コンクリートを用いたRC梁のせん断性状　　　　　　　　　　　　　　　
  武田亮祐; 睦好宏史; 浅本晋吾; 渡邉光
  Volume：32, 2010, [Reviewed]
  ISSN：2424-0281, J-Global ID：201002215465890150
• AN INVESTIGATION INTO WATER BEHAVIOR IN MICROPORES BASED ON MOLECULAR DYNAMICS SIMULATION　　　　　　　　　　　　　　　
  OKAZAKI Shinichiro; ASAMOTO Shingo; KISHI Toshiharu
  Journal of Japan Society of Civil Engineers, Ser. E1 (Pavement Engineering), Volume：65, Number：3, First page：311, Last page：321, 2009, [Reviewed]
  For estimation of durability of concrete, it is important to understand the behavior of liquid water in micro pores. It is well-known that water permeability in concrete can be idealized by Darcy's law and water penetration is usually calculated based on the permeability coefficient. It was found, however, that there exists a non-linear relationship between permeation of water and hydraulic gradient through the Output-Method permeability test under different pressures and the friction phenomenon of water movement in fine pores was suggested. This research reveals that such static and kinetic friction behavior between micro pores and water were clarified using a molecular dynamics (MD) simulation.
  Japan Society of Civil Engineers, Japanese
  DOI：https://doi.org/10.2208/jsceje.65.311
  DOI ID：10.2208/jsceje.65.311, ISSN：1880-6066, J-Global ID：200902284956097649, CiNii Articles ID：80020392067
• 内部液体特性に基づく多孔質材料の体積変化機構に関する研究　　　　　　　　　　　　　　　
  加藤恭介; 浅本晋吾; 松井久仁雄
  コンクリート工学年次論文集, Volume：Vol.31, Number：No.1, First page：619, Last page：624, 2009, [Reviewed]
  ISSN：2424-0281, J-Global ID：201002213930818573
• Investigations into volumetric stability of aggregates and shrinkage of concrete as a composite　　　　　　　　　　　　　　　
  Shingo Asamoto; Tetsuya Ishida; Koichi Maekawa
  Journal of Advanced Concrete Technology, Volume：6, Number：1, First page：77, Last page：90, Feb. 2008, [Reviewed], [Lead]
  The authors aim to quantitatively understand the influence of various aggregate properties on concrete shrinkage behavior based on both experimental and numerical approaches. The multi-scale constitutive model reveals that differences in aggregate Young's modulus cannot be solely responsible for the observed significant difference in corresponding shrinkage behavior of concrete. Hence, shrinkage of the aggregate itself is considered as a possibility and an aggregate shrinkage model that takes into account the surface area and the degree of aggregate saturation is proposed on the basis of earlier experimental results. The proposed model reasonably simulates the greatly varying different shrinkage behavior of concretes with various types of aggregates. Copyright © 2008 Japan Concrete Institute.
  JAPAN CONCRETE INST, English, Scientific journal
  DOI：https://doi.org/10.3151/jact.6.77
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77949350383&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=77949350383&origin=inward
  DOI ID：10.3151/jact.6.77, ISSN：1346-8014, eISSN：1347-3913, CiNii Articles ID：130000080438, ORCID：20393226, SCOPUS ID：77949350383, Web of Science ID：WOS:000255404000005
• 3138 SHEAR CRACKING BEHAVIOR OF ULTRA-HIGH-STRENGTH PRESTRESSED REINFORCED CONCRETE BEAMS :　　　　　　　　　　　　　　　
  DE SILVA Sudhira; MUTSUYOSHI Hiroshi; ASAMOTO Shingo; MAEKAWA Atsushi
  Proceedings of the Japan Concrete Institute, Volume：Vol.30, Number：No.3, First page：823, Last page：828, 2008, [Reviewed]
  English
  ISSN：1347-7560, CiNii Articles ID：110009697879, CiNii Books ID：AA12600419
• 超高強度コンクリートを用いたPRC梁のひび割れ性状　　　　　　　　　　　　　　　
  前川敦; 睦好宏史; S. Silvia; 浅本晋吾
  Volume：Vol.30, Number：No.3, First page：637, Last page：642, 2008, [Reviewed]
  本研究では,160N/mm^2を超える超高強度コンクリートの曲げおよびせん断ひび割れ特性を明らかにするためRCおよびPRC梁の載荷実験を行い,普通強度コンクリートのひび割れ挙動との比較・検討を行った。高強度コンクリートのひび割れは骨材を貫通して進展するため,ひび割れ幅のばらつきが普通強度コンクリートと比べ大きくなった。また,初期のひび割れ幅が普通強度に比べ大きく,それに伴い曲げひび割れ幅は大きくなることが確認された。せん断挙動は非常に脆性的な破壊となり,せん断補強鉄筋の破断が観察された。せん断ひび割れ幅に関しては,超高強度コンクリートを用いたPRC部材で小さくなることが確認された。
  Japanese
  ISSN：1347-7560, J-Global ID：200902259141379874, CiNii Articles ID：110009697848, CiNii Books ID：AA12600419
• Corrosion of reinforcements in RC and PRC beams by electrically accelerated corrosion test　　　　　　　　　　　　　　　
  KAWANA Keiko; NISHIOKA Tomoki; MUTSUYOSHI Hiroshi; ASAMOTO Shingo
  Proceedings of the Japan Concrete Institute, Volume：Vol.30, Number：No.1, First page：825, Last page：830, 2008, [Reviewed]
  本研究は,ひび割れを人為的に導入したRC部材よびPRC部材を対象に,腐食促進実験を行って各部材の劣化メカニズムについて実験的検討を行い,鋼材腐食による劣化後の供試体の状態を実環境下における供用年数と関連付けるために,Fickの拡散則やファラデーの法則を用いて解析的検討を行った。その結果,腐食環境下においては,ひび割れの発生を許容するRC部材に比べ,ひび割れ幅を制御することができるPRC部材の方が銅材腐食の進行を抑制できることが明らかとなった。飛沫帯環境下で供用されたと仮定した場合,PRC供試体は通電を開始してから,2週間で実構造物の約32年間に相当することが確認された。
  Japanese
  ISSN：1347-7560, J-Global ID：200902215782854141, CiNii Articles ID：110009697535, CiNii Books ID：AA12600419
• 1076 Influence of Rain and Sun Radiation on Shrinkage Behavior of Concrete　　　　　　　　　　　　　　　
  OTSUKA Ayumu; MIURA Chikako; ASAMOTO Shingo; MUTSUYOSHI Hiroshi
  Proceedings of the Japan Concrete Institute, Volume：Vol.30, Number：No.1, First page：501, Last page：506, 2008, [Reviewed]
  本研究では,貝射および降雨がコンクリートの収縮に与える影響の抽出を目的に系統的な実験を行った。環境条件が異なる三ヶ所の屋外環境に供試体を暴露し収縮の経時変化を計測した結果,降雨浸透によって収縮が大きく抑制されることが確認された。また,コンクリートの収縮ひずみが概ね等しい場合でも,乾燥を促進する日射の有無によって表面の収縮ひび割れ発生に顕著な差が現れることが分かった。さらに,既存の収縮予測式との比較を通じ,乾燥中に計測した平均湿度では雨水浸透による収縮回復の予測は難しく,境界条件によって異なる収縮挙動を予測するには局所的な降雨の影響を考慮する必要があることが分かった。
  Japanese
  ISSN：1347-7560, J-Global ID：200902227094184840, CiNii Articles ID：110009697481, CiNii Books ID：AA12600419
• 長期屋外乾燥させたPRC梁の曲げひび割れ性状に関する研究　　　　　　　　　　　　　　　
  浅本晋吾; 篠崎裕生; 三上浩; 睦好宏史
  Volume：Vol.30, Number：No.3, First page：559, Last page：565, 2008, [Reviewed], [Lead]
  本研究は,PRC梁を約1年半屋外で乾燥させたときの時間依存変形挙動,収縮ひび割れ,および乾燥後の曲げひび割れ性状について検討を行った。収縮ひび割れ進展を含む時間依存変形挙動について,材料と構造解析を組み合わせたマルチスケール統合解析システムで検討を行った結果,目視で確認できない微細ひび割れの存在が示唆された。また,膨張材及びビニロン短繊維を混入した際の収縮ひび割れ抑制,曲げひび割れ特性について実験的検討を行い,収縮ひび割れ抑制には膨張材が効果的であり,わずかな短繊維混入は曲げひび割れ性状に対しては影響が小さいが,ひび割れ発生後の曲げ剛性向上には寄与することが分かった。
  Japanese
  ISSN：1347-7560, J-Global ID：200902266454849258, CiNii Articles ID：110009697835, CiNii Books ID：AA12600419
• Enhancement of RC Bridge Management System and Application to Actual bridges　　　　　　　　　　　　　　　
  TAKASE Hayato; MUTSUYOSHI Hiroshi; NODA Kazuhiro; ASAMOTO Shingo
  Proceedings of the Japan Concrete Institute, Volume：Vol.29,No.3, Number：3, First page：1711, Last page：1716, 2007, [Reviewed]
  本研究では,昨年度提案したRC橋梁健全度診断システムの高度化,及び実橋梁への適用範囲について検討を行った。健全度診断システム内で用いる重みを変更することで,目視による点検が困難な点検項目のある橋梁に対しての適用範囲拡大を試みた。点検未記入項を診断時に危険側に評価しないことにより,点検者によるばらつきを抑え,より妥当な健全度評価実現を図った。高度化した本診断システムの妥当性を検証するため,埼玉県の実RC橋梁に対し点検を行い,健全度を診断した°その結果,本診断システムは目視点検が困難な橋梁に対しても適用可能であることが確認され,健全度評価改善に成功した。
  Japanese
  ISSN：1347-7560, J-Global ID：200902251303419190, CiNii Articles ID：110009697391, CiNii Books ID：AA12600419
• 高強度コンクリートを用いたPRC梁におけるひび割れ特性　　　　　　　　　　　　　　　
  高木真由子; 睦好宏史; S. Silvia; 浅本晋吾
  Volume：Vol.29,No.3, Number：3, First page：577, Last page：582, 2007, [Reviewed]
  ISSN：1347-7560, J-Global ID：200902287150901188
• 膨張剤およびビニロン短繊維を用いたコンクリートのひび割れ特性に関する実験的研究　　　　　　　　　　　　　　　
  玉置一清; 睦好宏史; 浅本晋吾; 三上浩
  Volume：Vol.29,No.1, Number：1, First page：807, Last page：812, 2007, [Reviewed]
  本研究は,経済的なひび割れ制御の一方策として,収縮補償レベルの膨張材量および少量のビニロン短繊維混入の有効性を検証する目的で,の軸鉄筋拘束試験体を実環境下で暴露した後,引張試験を実施したものである。検討の結果,膨張材の効果は5ヶ月後においても持続し,定量的な評価が可能であること,ビニロン短繊維を少量混入した場合,テンションステフィニング効果としてはばらつきがあるものの,微細な初期ひび割れの影響を緩和する効果があることなどが明らかになった。
  Japanese
  ISSN：1347-7560, J-Global ID：200902263552221055, CiNii Articles ID：110009696863, CiNii Books ID：AA12600419
• 実環境作用に着目したコンクリートの収縮特性に関する研究　　　　　　　　　　　　　　　
  浅本晋吾; 玉置一清; 大塚歩; 睦好宏史
  Volume：Vol.29,No.1, Number：1, First page：681, Last page：686, 2007, [Reviewed], [Lead]
  本研究は,外気温・湿度変動,雨天,日射といった実環境作用がコンクリートの収縮挙動に与える影響に着目して検討を行った。温湿度変化が概ね等しい屋内外の各環境条件に供試体を暴露し収縮の経時変化を計測した結果,降雨による水分浸透の影響は大きく,屋内に比べ屋外の収縮量は小さいことが分かった。さらに,マルチスケール複合構成モデルの適用性を検討した結果,降雨の影響を除いた実環境作用下における収縮挙動は平均湿度境界条件で概ね追跡が可能であるが,雨天による局所的な収縮回復を再現するには降雨浸透境界モデルが必要であることがわかった。また,骨材自体の収縮特性の違いにより収縮挙動が異なることが示唆された。
  Japanese
  ISSN：1347-7560, J-Global ID：200902278505785398, CiNii Articles ID：110009696842, CiNii Books ID：AA12600419
• ANALYSIS OF CONCRETE SHRINKAGE COUPLING WITH PROPERTIES OF AGGREGATE　　　　　　　　　　　　　　　
  ASAMOTO Shingo; ISHIDA Tetsuya; MAEKAWA Koichi
  Doboku Gakkai Ronbunshuu E, Volume：63, Number：2, First page：327, Last page：340, 2007, [Reviewed], [Lead]
  In this research, authors aim to quantitatively understand the influence of various aggregate properties on behaviors of concrete shrinkage based on both experimental and numerical approach. A multi-scale constitutive model revealed that only difference of aggregate Young’s modulus cannot cause significantly different shrinkage behaviors of concrete. Thus, the shrinkage of aggregate itself was focused on and aggregate shrinkage model that depends on its surface area and saturation degree according to experimental results of previous researches was proposed. The proposed model can reasonably simulate largely different shrinkage behaviors of concrete with various types of aggregates.
  Japan Society of Civil Engineers, Japanese
  DOI：https://doi.org/10.2208/jsceje.63.327
  DOI ID：10.2208/jsceje.63.327, ISSN：1880-6066, J-Global ID：200902258896811770, CiNii Articles ID：130004943117
• SHEAR CRACKING BEHAVIOR OF HIGH-STRENGTH PRESTRESSED REINFORCED CONCRETE BEAMS　　　　　　　　　　　　　　　
  Sudhira DE SILVA; MUTSUYOSH Hiroshi; ASAMOTO Shingo; TAKAGI Mayuko
  Proceedings of the Japan Concrete Institute, Volume：29, Number：3, First page：679, Last page：684, 2007, [Reviewed]
  English
  ISSN：1347-7560, CiNii Articles ID：110009697219, CiNii Books ID：AA12600419
• Time-Dependent Constitutive Model of Solidifying Concrete Based on Thermodynamic State of Moisture in Fine Pores　　　　　　　　　　　　　　　
  Shingo Asamoto; Tetsuya Ishida; Koichi Maekawa
  Journal of Advanced Concrete Technology, Volume：4, Number：2, First page：301, Last page：323, Jun. 2006, [Reviewed], [Lead]
  Japan Concrete Institute, Scientific journal
  DOI：https://doi.org/10.3151/jact.4.301
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33845640530&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=33845640530&origin=inward
  DOI ID：10.3151/jact.4.301, ISSN：1346-8014, eISSN：1347-3913, CiNii Articles ID：130000080306, ORCID：20393227, SCOPUS ID：33845640530
• 温度履歴に依存するセメント硬化体の細孔内水分状態と体積変化機構の連関　　　　　　　　　　　　　　　
  浅本晋吾; 石田哲也
  Volume：Vol.27, No.1, Number：1, First page：451, Last page：456, 2005, [Reviewed], [Lead]
  本研究では,細孔空隙中の水分状態が体積変化に与える影響を,温度履歴の観点から捉えることを目的とした。一定の高温乾燥後,封緘状態を与えた場合,収縮の顕著な回復が観察された。これは高温履歴のみに見られる挙動であり,封緘下での内在水分の再分配により,相対湿度の上昇が生じたと推察した。さらに常温・高温乾燥実験の比較検討を行い,細孔内水分の温度依存性がもたらす力学的特性について考察を行った。以上の検討を通じて,任意の温度環境における水分状態と体積変化機構の連関を強化したコンクリートの複合構成則の提案を行った。
  Japanese
  ISSN：1347-7560, J-Global ID：200902282612887630, CiNii Articles ID：110009695574, CiNii Books ID：AA12600419
• MICROSCOPIC APPROACH TO TIME-DEPENDENT DEFORMATION MECHANISM OF CONCRETE BASED ON LIQUID CHARACTERISTICS　　　　　　　　　　　　　　　
  ASAMOTO Shingo; ISHIDA Tetsuya
  Number：760, First page：159, Last page：172, 2004, [Reviewed], [Lead]
  Japanese
  DOI：https://doi.org/10.2208/jscej.2004.760_159
  DOI ID：10.2208/jscej.2004.760_159, ISSN：0289-7806, CiNii Articles ID：10012364562, CiNii Books ID：AN10014020
• コンクリートのクリープ・収縮に与える微細空隙中の液体特性及び分布の影響　　　　　　　　　　　　　　　
  浅本晋吾; 石田哲也
  Volume：Vol.25, Number：No.1, First page：509, Last page：514, 2003, [Reviewed], [Lead]
  本研究では,コンクリートの内部にある液体の特性及び分布がクリープ・収縮に与える影響について検討を行った。セメントペースト硬化後に絶乾を施し,各種液体に浸漬させ,収縮ひずみ・飽和度の経時変化の検討及びクリープ実験を行った。その結果,水を浸漬したときのみ飽和度・絶乾による収縮が大きく回復し,クリープ挙動も発生した。水以外の液体は微細空隙に浸漬しないことから,nmレベルのゲル・層間空隙,結晶といった微視的空隙にある水の特異な特性がクリープ・収縮に大きく影響していることが解った。
  Japanese
  ISSN：1347-7560, J-Global ID：200902222835338481, CiNii Articles ID：110009694291, CiNii Books ID：AA12600419
• ECCの疲労解析モデルの構築　　　　　　　　　　　　　　　
  松本高志; S. Peerapong; 浅本晋吾
  Volume：vol.24, Number：No.1, First page：237, Last page：242, 2002, [Reviewed]
  歪み硬化型高靭性セメント複合材料(ECC)の疲労解析モデルを構築した。ECCの複数ひび割れによる損傷領域の広がりとひび割れ局所化・進展を考慮している。ひび割れにおける伝達応力の疲労劣化が繊維疲労破断に起因するとし,伝達応力劣化関数の形で含めることにより疲労解析を行っている。ECCの曲げ疲労実験によるS-N曲線を解析モデルによる計算値と比較することにより妥当性を検証した。
  Japanese
  ISSN：1347-7560, J-Global ID：200902168141674293, CiNii Articles ID：110009693683, CiNii Books ID：AA12600419

• コンクリートとAI/2.設計分野 機械学習によるコンクリートの乾燥収縮の回帰分析と定式化　　　　　　　　　　　　　　　
  岡崎百合子; 岡崎慎一郎; 浅本晋吾; 今本啓一
  Volume：62, Number：9, 2024
  ISSN：0387-1061, J-Global ID：202402263879197091
• 日本インフラの「強み」と「オリジナリティ」はどこに?-求められる将来に向けた『進化』-第11回 No.10 マスコンクリートのひび割れ制御技術-大型構造物の新規建設の少ない今,目指す展開は?-　　　　　　　　　　　　　　　
  浅本晋吾
  Volume：105, Number：9, 2020
  ISSN：0021-468X, J-Global ID：202002261963754471
• Influence of High Temperature on Concrete Performance　　　　　　　　　　　　　　　
  浅本晋吾; 岡崎慎一郎; 蔵重勲; 千々和伸浩; 川端雄一郎
  コンクリート工学, Volume：57, Number：6, First page：426, Last page：432, Jun. 2019, [Reviewed]
  ISSN：0387-1061, J-Global ID：201902291702079683
• 熱力学的相平衡計算に基づく系内に存在する炭酸カルシウムがettringiteの安定性に及ぼす影響　　　　　　　　　　　　　　　
  浅本晋吾; 宮本慎太郎
  Volume：JCI-C98, 2019
  J-Global ID：202002222255679300
• 「DEFのリスクを考える」に関するシンポジウム 委員会報告書　　　　　　　　　　　　　　　
  川端雄一郎; 羽原俊祐; 小川彰一; 兵頭彦次; 吉田夏樹; 浅本晋吾; 東洋輔; 五十嵐豪; 上原元樹; 臼井達哉; 蔵重勲; 斎藤豪; 玉滝浩司; 寺本篤史; 取違剛; 松下哲郎; 野村博史; 宮本慎太郎; 村岡史朗; 森泰一郎; 西岡由紀子
  Volume：JCI-C98, 2019
  J-Global ID：202002219324875042
• Hydration and heat development　　　　　　　　　　　　　　　
  Laurie Lacarrière; Agnieszka Knoppik; Wilson Ricardo Leal da Silva; Tulio Honorio; Vit Šmilauer; Shingo Asamoto; Eduardo M.R. Fairbairn
  RILEM State-of-the-Art Reports, Volume：27, First page：13, Last page：46, 2019
  © 2019, RILEM. The driving process of early-age cracking in massive element is the hydration and reactions of the binder that composes the concrete. Indeed, these reactions are highly exothermic and lead to heat generation in the structure. It is thus of primary importance to be able to characterise and predict the heat generation of binders in order to assess the early-age cracking risk of a concrete structure. The first section of this chapter presents the main physical phenomena responsible for this heat generation. It must be kept in mind that only the general phenomena of hydration are presented. The aim is only to present how the chemical reactions lead to heat development and water consumption (which are of interest for our purpose). The reactivity of binder is a large scientific subject, and more detailed review can be found on this subject in other RILEM TCs (for instance, 238-SCM). The second (and main) section of the chapter is dedicated to the modelling of the heat development induced by cement hydration. Several approaches are presented: affinity-based models (that can be easily implemented in finite element codes), microstructural models (even if they are less adapted to the massive structure modelling), data mining, or inverse analysis.
  DOI：https://doi.org/10.1007/978-3-319-76617-1_2
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85047660969&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85047660969&origin=inward
  DOI ID：10.1007/978-3-319-76617-1_2, ISSN：2213-204X, eISSN：2213-2031, SCOPUS ID：85047660969
• Cracking risk and regulations　　　　　　　　　　　　　　　
  Agnieszka Knoppik; Jean Michel Torrenti; Shingo Asamoto; Eduardus Koenders; Dirk Schlicke; Luis Ebensperger
  RILEM State-of-the-Art Reports, Volume：27, First page：257, Last page：306, 2019
  © 2019, RILEM. This chapter is focused on the cracking risk at early ages. After general considerations about cracking, the cracking risk prediction is discussed. Two main ways to assess this risk are considered: through an evaluation of the tensile stresses and through an evaluation of the strains. Finally, the evaluation of crack opening at early ages and the reinforcement design in regulations are presented.
  DOI：https://doi.org/10.1007/978-3-319-76617-1_8
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85047664807&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85047664807&origin=inward
  DOI ID：10.1007/978-3-319-76617-1_8, ISSN：2213-204X, eISSN：2213-2031, SCOPUS ID：85047664807
• コンクリートの性能に及ぼす高温作用の影響評価研究小委員会(352委員会)成果報告書
  佐藤良一; 坂井悦郎; 浅本晋吾; 蔵重勲; 岡崎慎一郎; 川端雄一郎; 千々和伸浩; 伊藤隼人; 上田尚史; 上原元樹; 臼井達哉; 大野拓也; 小川由布子; 木ノ村幸士; 久我龍一郎; 車谷麻緒; 斎藤豪; 坂本亮; 佐々木謙二; 佐藤正己; 高橋恵輔; 高橋佑弥; 玉滝浩司; 取違剛; 芳賀和子; 人見尚; 藤井隆史; 矢ノ倉ひろみ; 山田雅宏; 米田大樹; 関健吾
  コンクリート技術シリーズ, Number：120, First page：140P, 16 Oct. 2018
  Japanese
  J-Global ID：201902286436417676
• Template for paper submission to the Eleventh U.S. National Conference on Earthquake Engineering　　　　　　　　　　　　　　　
  J. Dang; A. Shrestha; X. Wang; S. Matsunaga; P. J. Chun; S. Asamoto
  11th National Conference on Earthquake Engineering 2018, NCEE 2018: Integrating Science, Engineering, and Policy, Volume：10, First page：6165, Last page：6175, 2018
  Copyright © 2018 Earthquake Engineering Research Institute. All rights reserved. This template illustrates the format that must be used in the preparation of papers for the Eleventh U.S. National Conference on Earthquake Engineering. Text and headings should be in 12-point type. Included in this template are examples of headings, equation format, references, and other typographical features likely to be encountered in technical papers. The abstract can be shorter than the originally submitted abstract. Maximum paper length is 11 pages, including the cover page. The cover page is in a format required by Google Scholars for proper indexing. A good abstract should be an informative summary of the most important results. It should not be a summary of subjects covered. It should avoid expressions such as "is discussed" and " is described." It should not include references, figures, or tables. The abstract is of utmost importance, because it is the most widely read portion of a manuscript.
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85085625400&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85085625400&origin=inward
  SCOPUS ID：85085625400
• LOW COST BRIDGE SEISMIC MONITORING APPLYING USED SMART PHONES AND CLOUD SERVER　　　　　　　　　　　　　　　
  Ji Dang; Ashish Shrestha; Xin Wang; Shogo Matsunaga; Pang-jo Chun; Shingo Asamoto
  Proceedings of Eleventh U.S. National Conference on Earthquake Engineering, First page：1124, 2018
  English
• 地域アセットマネジメントにおける簡易点検手法の適用に関する一考察　　　　　　　　　　　　　　　
  大窪 和明; 全 邦釘; 浅本 晋吾; 岡崎 慎一郎
  First page：117, Last page：122, Dec. 2017
  Japanese
• Mesoscopic analysis of different expansion causes in concrete by 3D Rigid Body Spring Model　　　　　　　　　　　　　　　
  EDDY Liyanto; AWASTHI Anupam; 松本浩嗣; 長井宏平; 浅本晋吾
  生産研究, Volume：69, Number：4, 2017
  ISSN：0037-105X, J-Global ID：201702273465439025
• Bridge Health Monitoring System Based on Smart Devices in Takamatsu Bridge　　　　　　　　　　　　　　　
  Ashish Shrestha; Ji Dang; Xin Wang; Shogo Matsunaga; Shingo Asamoto; Okubo Kazuaki; Pang-jo Chun
  Proceedings of 2nd JSCE-CICHE Joint Workshop, Volume：2, 2017
  English
• Characteristics of Bridge Deterioration based on inspection data in Japan　　　　　　　　　　　　　　　
  Kazuaki Okubo; Pang-jo Chun; Shingo Asamoto
  Proceedings of the Eastern Asia Society of Transportation Studies, Volume：11, 2017
  English
• セメント系構築物と周辺地盤の化学的相互作用研究小委員会(345委員会)成果報告書
  小峯秀雄; 坂井悦郎; 名和豊春; 前川宏一; 石田哲也; 半井健一郎; 乾徹; 蔵重勲; 斎藤豪; 芳賀和子; 細川佳史; 吉田亮; 浅本晋吾; 五十嵐豪; 伊代田岳史; 入江正明; 上田隆雄; 上田洋; 内村太郎; 梅村靖弘; 枝松良展; 大石幹太; 大和田仁; 川本健; 菊地道生; 木ノ村幸士; 清田正人; 黒澤進; 桑野玲子; 小高猛司; 酒井雄也; 佐藤周之; 杉橋直行; 杉山大輔; 須田裕哉; 高橋佑弥; 取違剛; 中村弘典; 二戸信和; 庭瀬一仁
  コンクリート技術シリーズ, Number：103, First page：I(1)-I(7),I-V,1-425,427-431, 03 Jul. 2014
  Japanese
  J-Global ID：201502242272304516
• 若材齢にクリープを促進したPC梁のプレストレス変化と構造性能に関する研究　　　　　　　　　　　　　　　
  浅本晋吾; 牧剛史; 加藤恭介; 今野由香里
  Volume：22nd, 2013
  J-Global ID：201302214554586494
• Detection of corrosion-induced damage in reinforced concrete beams based on structural damping identification
  S. Shahzad; H. Yamaguchi; R. Takanami; S. Asamoto
  Proceedings of the 13th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2013, 2013
  This article examines the possibility of corrosion damage detection in reinforced concrete (here after RC) beams based on modal damping changes. Four RC beams were damaged artificially by inducing uniform and localized corrosions on the beams. Modal tests were performed on the test beams before and after the corrosion damages, and extracted modal parameters were compared with each other. The result showed certain amount of changes in modal parameters, namely natural frequency and modal damping ratio, and the modal damping ratio was more sensitive than the natural frequency against corrosion-induced damages. This indicates that the local and small corrosion damage might be detectable by monitoring the modal damping ratio of RC structures.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84905223561&origin=inward
  ORCID put code：20393215, SCOPUS ID：84905223561
• Multi-scale modeling to link observed behavior, characterization and analysis
  H. Mihashi; K. Maekawa; T. Ishida; S. Asamoto; I. Maruyama
  Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures - Proceedings of the 8th Int. Conference on Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures, Volume：1, First page：117, Last page：143, 2009
  This paper provides an overview of the mathematical modeling for time-dependent behaviour of cementitious materials. Since the cementitious materials have complex and multi-scale structures, the modeling need to bridge a very wide range of the order from nano-scale for material science level to meter-scale for structural analysis. Furthermore the structure of the cementitious materials is formed through chemical reaction and changes with time as a function of the environmental condition. Thus analytical models for observed behaviour in the cementitious materials need to be sufficiently comprehensive and precise characterization for material structure and measurement of the environmental conditions are essential for building up the constitutive models.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952341754&origin=inward
  ORCID put code：20393222, SCOPUS ID：79952341754
• Multi-scale constitutive model of solidifying concrete coupled with micro-physical properties of cementitious composites
  T. Ishida; K. Maekawa; A. Bongochgetsakul; S. Asamoto
  Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures - Proceedings of the 8th Int. Conference on Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures, Volume：1, First page：145, Last page：151, 2009
  Multi-scale constitutive modeling of solidifying concrete for creep and shrinkage prediction is presented as a systematic knowledge base of coupled cementitious composites and structural mechanics. In this study, present model of micro-pore structure development, moisture equilibrium and transport, and the time-dependent constitutive law are enhanced through experimental verifications and sensitivity analyses, he authors proposed model for predicting moisture transport and water content under arbitrary temperature by enhancing an existing model. The equilibrium relationship among pore pressure, saturated/absolute vapor pressure was described, and the flux of vapor and liquid water has been generalized with respect to temperature. The enhanced model of moisture transport and equilibrium has been coupled with a multi-chemo-physical model for the time-dependent deformation of concrete. Through systematic experimental verifications, it was shown that the model has potential to simulate time-dependent deformations such as autogenous/drying shrinkage and basic/drying creep in laboratory tests under arbitrary environmental and loading conditions. © 2009 Taylor & Francis Group.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952324030&origin=inward
  ORCID put code：20393220, SCOPUS ID：79952324030
• Multi-scale analysis of concrete shrinkage coupling with aggregate properties
  S. Asamoto; T. Ishida; K. Maekawa
  Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures - Proceedings of the 8th Int. Conference on Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures, Volume：1, First page：161, Last page：167, 2009
  The authors aim to quantitatively understand the influence of various aggregate properties on concrete shrinkage behavior based on microscopic information of hardening cement paste and aggregate. The multi-scale constitutive model reveals that differences in aggregate Young's modulus cannot be solely responsible for the observed significant difference in corresponding shrinkage behavior of concrete. Hence, shrinkage of the aggregate itself is considered as a possibility and the integrated concrete shrinkage simulation is carried out coupling with an aggregate shrinkage model related to the moisture state in aggregate pores. The model reasonably simulates the greatly varying shrinkage behavior of concretes with various types of aggregates taking into account aggregate shrinkage. © 2009 Taylor & Francis Group.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952332456&origin=inward
  ORCID put code：20393219, SCOPUS ID：79952332456
• Influences of environmental factors on shrinkage behavior of concrete
  A. Otsuka; S. Asamoto; C. Miura
  Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures - Proceedings of the 8th Int. Conference on Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures, Volume：2, First page：1419, Last page：1425, 2009
  In this study, the authors focus on concrete shrinkage behavior under different environmental conditions. The influences of both rain and sun radiation are investigated for understanding the dominant environmental factors on the concrete shrinkage. Prismatic specimens with different water-to-cement ratios were exposed to three outdoor conditions in order to examine rain and sun radiation effects separately. Furthermore, for the purpose of studying the effect of rain and sun radiation on shrinkage cracking on the surface of Rein-forced Concrete (RC) members, the shrinkage cracking behavior of concrete was also measured. Through the comprehensive interpretation of various experimental results, it is concluded that the rain greatly inhibits the shrinkage of plain concrete but the effect of sun radiation is relatively small, while shrinkage cracking behavior can be strongly affected by sun radiation. © 2009 Taylor & Francis Group.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952337955&origin=inward
  ORCID put code：20393221, SCOPUS ID：79952337955
• Concept of Concrete Bridge Maintenance and its Application　　　　　　　　　　　　　　　
  MUTSUYOSHI H.; ASAMOTO S.; TAKASE H.
  コンクリート工学, Volume：46, Number：3, First page：10, Last page：16, 01 Mar. 2008
  Japanese
  ISSN：0387-1061, J-Global ID：200902254193557981, CiNii Articles ID：10020242486, CiNii Books ID：AN00094169
• Multi-scale time-dependent deformation model of solidifying cementitious materials coupling with aggregate properties　　　　　　　　　　　　　　　
  S. Asamoto; T. Ishida; K. Maekawa
  First page：225, Last page：232, 2008
• Hybrid FRP composite I-beams consisting of CF/GFRP　　　　　　　　　　　　　　　
  H. Mutsuyoshi; N. D. Hai; S. Asamoto; A. C. Manalo; T. Matsui
  Proceedings of the 4th International Conference on FRP Composites in Civil Engineering, CICE 2008, 2008, [Reviewed]
  © 2008 Empa-Akademie. All rights reserved. A hybrid Fiber Reinforced Polymer (FRP) composite consisting of Carbon Fiber Reinforced Polymers (CFRP) and Glass Fiber Reinforced Polymers (GFRP) has been developed in Japan. The innovative feature of this beam is the combined use of CFRP and GFRP in flanges to increase the stiffness, while only GFRP is utilized in the web to reduce the overall cost. A number of tensile and compressive coupon tests were conducted to determine the material properties which were used in the analytical investigations of the large-scale beams. A series of large-scale beams were tested under four-point bending varying the volume content of CFRP in flanges. Preliminary experimental results revealed that the beams failed due to the crushing of fibers near the loading point and owing to the delamination of the compressive flange between the interface of CFRP and GFRP layers. The failure mode of beams depends upon the volume content of CFRP in flanges. In addition, three-dimensional finite element analysis was carried out and showed a good correlation with experimental results.
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79952209100&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952209100&origin=inward
  SCOPUS ID：79952209100
• Mechanical behavior of hybrid FRP composites with bolted joints　　　　　　　　　　　　　　　
  A. C. Manalo; H. Mutsuyoshi; S. Asamoto; T. Aravinthan; T. Matsui
  Futures in Mechanics of Structures and Materials - Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, ACMSM20, First page：47, Last page：53, 2008, [Reviewed]
  The behavior of an innovative hybrid Fibre Reinforced Polymer (FRP) composite with bolted joints was investigated. Coupons and full-size specimens were tested to determine the effect of applied bolt-torque and the contribution of adhesive bonding on the load capacity and failure mode of the hybrid FRP with bolted joints. The results showed that at different levels of applied bolt torque (10, 15, 20 and 25 N-m), little friction resistance developed. A slight increase on the load capacity was however observed with increasing tightening torque. On the other hand, the bolting accompanied by adhesive bonding provided resistance against slipping. The full-size hybrid FRP girder with joints using bolts and epoxy exhibited the same strength and stiffness as the girder without joints while bolting alone resulted to a beam with only 65% of the stiffness of those without joints. Theoretical analyses were conducted and result showed a good agreement with the experimental results. © 2009 Taylor & Francis Group, London.
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79952224570&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952224570&origin=inward
  ORCID put code：20393224, SCOPUS ID：79952224570
• Experimental investigation of innovative hybrid composite girders with GFRP and CFRP　　　　　　　　　　　　　　　
  S. Asamoto; H. Mutsuyoshi; T. Aravinthan; K. Suzukawa
  Proceedings of the 4th International Structural Engineering and Construction Conference, ISEC-4 - Innovations in Structural Engineering and Construction, Volume：1, First page：669, Last page：675, 2008, [Reviewed]
  This paper focuses on flexural behavior of innovative hybrid I-shaped girders consisting of Glass Fiber Reinforced Plastics and Carbon Fiber Reinforced Plastics. The experimental investigation revealed that the delamination at the interface of glass and carbon fibers in the compressive flange caused a sudden failure and lead to smaller loading capacity than the expected in the case of girders with smaller flange width. In the case of wider flange width, the local buckling of flange in compressive side was observed. It was experimentally found that the appropriate installation of web stiffeners is an effective way to prevent the local buckling of wide flange sections but that FRP materials cannot also exhibit their intrinsic material strength due to the delamination. In order to utilize the materials properties of FRP effectively, it is recommended that further study is conducted with a section having neutral axis towards the upper side of the section. © 2008 Taylor & Francis Group.
  TAYLOR & FRANCIS LTD, English
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=55549147546&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=55549147546&origin=inward
  ORCID put code：20393225, SCOPUS ID：55549147546, Web of Science ID：WOS:000253973500102
• Composite behavior of hybrid CFRP-GFRP bridge girders　　　　　　　　　　　　　　　
  H. Mutsuyoshi; N. D. Hai; S. Asamoto; H. Minn; T. Matsui
  Futures in Mechanics of Structures and Materials - Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, ACMSM20, First page：61, Last page：67, 2008, [Reviewed]
  A hybrid FRP bridge girder consisting of CFRP and GFRP has been developed in Japan. A number of tensile and compressive coupon tests were conducted to determine the material properties of hybrid FRP laminates which were used in the analytical investigations of the large-scale FRP beams. A series of beams with wide flange widths varying the volume content of CFRP in flanges were tested under four-points loading. The experimental investigations revealed that the failure mode of these beams was induced by the local buckling of the compressive flange. In order to avoid the local buckling, stiffeners were installed in the flexural and shear span of beams. Although an appropriate installation of stiffeners can prevent the buckle of beams, however FRP materials cannot perform their superior material strengths in tension and compression. Therefore, further developments are necessary to utilize FRP composite more effectively. Analyses were carried out and showed a good correlation with experimental results. © 2009 Taylor & Francis Group, London.
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79952213274&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79952213274&origin=inward
  ORCID put code：20393223, SCOPUS ID：79952213274
• Flexural behavior of hybrid FRP girder with concrete deck　　　　　　　　　　　　　　　
  H. Mutsuyoshi; T. Aravinthan; S. Asamoto; A. C. Manalo; K. Suzukawa
  Proceedings of the 1st Asia-Pacific Conference on FRP in Structures, APFIS 2007, Volume：2, First page：1107, Last page：1112, 2007
  © 2007 International Institute for FRP in Construction An innovative hybrid composite girder is being developed in Japan consisting of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP). The innovative feature of this girder is the optimum use of CFRP and GFRP in flanges to maximize structural performance while reducing the overall cost by using only GFRP in the web section. The flexural behavior of such hybrid FRP composite girders was investigated. Preliminary tests revealed that hybrid FRP girder failed due to local buckling and separation of laminates in the compression flange with the tensile strain much lower than the expected maximum strain. In view of improving its structural performance and practical application, concrete deck was provided on top of the hybrid FRP composite girder to avoid local brittle failure and to fully utilize the superior characteristics of the FRP materials. Different types of shear connection were trialed to provide composite action between the hybrid FRP girder and concrete deck. This paper will discuss the results of the experimental investigation on the combined section of concrete deck and hybrid FRP composite girder focusing mainly on issues related to the composite action of such girders.
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85083566815&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85083566815&origin=inward
  SCOPUS ID：85083566815
• Multi-scale Constitutive Model of Solidifying Cementitious Composites and Application to Cracking Assessment of a Concrete Structure　　　　　　　　　　　　　　　
  Ishida, T; Asamoto, S; Maekawa, K
  First page：85, Last page：99, 2006
• Effect of aggregate stiffness and porosity on shrinkage of concrete
  Yasuaki Furuya; Shingo Asamoto; Tetsuya Ishida
  Materials, Experimentation, Maintenance and Rehabilitation - Proceedings of the 10th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2010, First page：737, Last page：742, 2006
  This study aims to clarify the influence of water absorption and stiffness of gravels on autogenous and drying shrinkage of concrete. In order to extract their contribution to shrinkage, normal gravel, lightweight gravel and epoxy-coated lightweight gravel were used in shrinkage tests. According to our experimental results, water migration from gravel affects autogenous shrinkage but has little relation with drying shrinkage. It was noticed that the effect of gravel stiffness was much more significant on drying shrinkage than on autogenous shrinkage while the water absorption has lager influence on autogenous shrinkage than drying shrinkage. The observed results were compared with the multi-scale constitutive model for time-dependent deformation, developed in the author's research group. The model can compute drying shrinkages with concretes having different aggregates reasonably. Though the analytical results are somewhat larger than the experimental results in the case of autogenous shrinkage at an early age, the effect of aggregate stiffness and porosity on shrinkage of concrete can be simulated. © 2006 by School of Engineering and Technology, Asian Institute of Technology.
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84886704338&origin=inward
  ORCID put code：20393228, SCOPUS ID：84886704338
• Influence of Thermo-Hygro Profile and Micro-Pore Characteristic on Time-Dependent Mechanical Behavior of Concrete　　　　　　　　　　　　　　　
  Shingo ASAMOTO; Tetsuya ISHIDA
  Proceedings of the 9th East Asia-Pacific Conference on Structural Engineering and Construction (EASEC9), Volume：CMD, First page：8, Last page：13, 2003
• Influence of liquid characteristic and its distribution in micro-pore on time-dependent mechanical behavior of concrete　　　　　　　　　　　　　　　
  Shingo ASAMOTO; Tetsuya ISHIDA
  Engineering Conference on Advances in Cement and Concrete, First page：181, Last page：190, 2003

• 日本インフラの「技」 : 原点と未来　　　　　　　　　　　　　　　
  中居, 楓子; 浅本, 晋吾; 家田, 仁; 土木学会; 土木学会土木学会誌編集委員会
  Dec. 2022
  Japanese, Total pages：288p
  CiNii Books：http://ci.nii.ac.jp/ncid/BD00514739
  ISBN：9784810610550, CiNii Books ID：BD00514739

• Japan Concrete Institute
• Japan Society of Civil Engineers
• RILEM

• 高炉セメントコンクリートのひび割れ要件解明と水和物形態に基づく収縮抑制手法の開発　　　　　　　　　　　　　　　
  01 Apr. 2023 - 31 Mar. 2026
  Grant amount(Total)：18460000, Direct funding：14200000, Indirect funding：4260000
  Grant number：23K26173
• Study on CO2 capture technology utilizing construction wastes and the corresponding composites of organic and inorganic materials　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), 01 Apr. 2023 - 31 Mar. 2026
  Kagawa University
  Grant amount(Total)：4680000, Direct funding：3600000, Indirect funding：1080000
  Grant number：23K03987
• 高炉セメントコンクリートのひび割れ要件解明と水和物形態に基づく収縮抑制手法の開発　　　　　　　　　　　　　　　
  01 Apr. 2023 - 31 Mar. 2026
  Grant amount(Total)：18460000, Direct funding：14200000, Indirect funding：4260000
  Grant number：23H01479
• 塩化物を高含有したコンクリートの腐食抑制効果と物性評価　　　　　　　　　　　　　　　
  30 Jun. 2023 - 31 Mar. 2025
  Grant amount(Total)：6240000, Direct funding：4800000, Indirect funding：1440000
  Grant number：23K17768
• 深層学習を実装した微細構造解析による鉄筋コンクリート内部損傷の逆推定と性能評価　　　　　　　　　　　　　　　
  01 Apr. 2022 - 31 Mar. 2025
  Grant amount(Total)：42640000, Direct funding：32800000, Indirect funding：9840000
  Grant number：22H00224
• A New AI Method for Bridge Inspection and Diagnosis that Combines CNN with Highly Accurate Damage Detection and Expertises　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), 01 Apr. 2021 - 31 Mar. 2024
  The University of Tokyo
  Grant amount(Total)：17420000, Direct funding：13400000, Indirect funding：4020000
  Grant number：21H01417
• 材料及び環境条件に基づくDEF膨張の発生・抑制機構の解明と構造性能への影響評価　　　　　　　　　　　　　　　
  01 Apr. 2020 - 31 Mar. 2023
  Grant amount(Total)：17680000, Direct funding：13600000, Indirect funding：4080000
  Grant number：20H02219
• Multiscale Modeling of Cementitious Materials and Structures based on Properties of Calcium Silicate Hydrates　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), 01 Apr. 2017 - 31 Mar. 2020
  Ishida Tetsuya, The University of Tokyo
  Grant amount(Total)：44200000, Direct funding：34000000, Indirect funding：10200000
  The objective of this study was to construct a multiscale thermodynamic model and a time-dependent constitutive law that take into account the properties of calcium silicate hydrates, whose characters are different depending on the type of binder, and to develop a numerical analysis scheme to directly evaluate both the microscopic properties of cementitious materials and the macroscopic behavior of structures. A model describing the hydration reaction of fly ash with various physico-chemical compositions was developed in a unified framework, and a generalized model including both artificial pozzolans and natural pozzolans was successfully constructed. In addition, we focused on the connectivity of pore structures and attempted to elucidate the mechanism of water and ion transport in microstructures, and found that the threshold value of water content that ensures pore connectivity can be uniquely determined regardless of the porosity.
  Grant number：17H01284
• Study on interface variation between different materials in concrete depending on temperature history during hardening and its association with durability　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 01 Apr. 2017 - 31 Mar. 2020
  Asamoto Shingo, Saitama University
  Grant amount(Total)：16770000, Direct funding：12900000, Indirect funding：3870000
  This study investigated the damage around constitutive materials of concrete and the subsequent change of material properties when the high temperature over 70 C is exposed to concrete at early ages. It is suggested that the high temperature can cause the micro damages at the interfacial zones depending on the materials and the resistivity of concrete to mass transfer of harmful materials may be decreased due to the damage. It is also found that the volumetric change and deformation characteristics can increase according to the materials and initial temperature history. The experimental and numerical analysis indicated that the swelling arising from the high temperature at early ages can be accelerated by carbonate ion. The long-term inhibition of the swelling by the coal ash was also experimentally confirmed.
  Grant number：17H03285
• Heat transfer phenomena and its suitable boundary conditions of geomaterials under cooling and heating process　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), 01 Apr. 2014 - 31 Mar. 2019
  Yamabe Tadashi, Saitama University
  Grant amount(Total)：30680000, Direct funding：23600000, Indirect funding：7080000
  To investigate the heat transfer characteristics of sand stone due to cooling and heating process, cylinder of 50mm diameter and sphere of 50mm and 100mm diameter were used as the samples. Two types of boundary conditions had been used for the derivation of exact solutions of the governing equations. They were Dirichlet boundary (DB) and heat transfer boundary (HTB) conditions. Hence, comparison had been made on these two boundary conditions to identify their suitability on heat transfer characteristics. The results show that the exact solutions derived using HTB has been fitted better than DB for both cooling and heating phenomenon in cylinders as well as in spheres.
  Grant number：26249068
• Maintenance and Long Life Sustainabilty of Prestressed Concrete Bridges　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 01 Apr. 2015 - 31 Mar. 2018
  MUTSUYOSHI Hiroshi; SANADA Osamu; AOKI Keiichi, Saitama University
  Grant amount(Total)：17810000, Direct funding：13700000, Indirect funding：4110000
  In order to clarify the flexural behavior of prestressed concrete (PC) beams having damaged tendons. The tendons of the PC beams were intentionally broken by a core drilling machine or accelerated corrosion process. The loading tests were carried out to investigate the influence of location and degree of damage of the tendons on the load carrying capacity of the PC beams. A nonlinear pushover analysis was also performed using fiber model and the analytical results were verified by the experimental results. From the analysis it was found that the load carrying capacity of the PC beams having damaged tendons can be estimated with good accuracy. Furthermore, the fiber model was applied for actual PC box bridges assuming the degree of corrosion damage of the PC tendons and the location of the corrosion. The analytical results were used to estimate the safety of the PC box bridges when the tendons are heavily corroded.
  Grant number：15H04029
• Long-term behavior of joint connection in steel-concrete hybrid structural system　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 01 Apr. 2015 - 31 Mar. 2018
  Maki Takeshi, Saitama University
  Grant amount(Total)：18460000, Direct funding：14200000, Indirect funding：4260000
  The long-term external load acting on steel-concrete joint connection in steel-concrete hybrid structural system may induce additional deformation in shear connectors and their surrounding concrete. The long-term slip increment in shear connecting system leading to the deformation of joint connection is experimentally and numerically clarified in this research. The push-out test specimens with headed stud shear connectors were loaded with sustained external shear force for a month, and the long-term slip was numerically simulated by nonlinear finite element analysis. Furthermore, the long-term sustained loading test of joint connection between composite girder and prestressed concrete girder was also conducted so that the long-term deflection increment under various load level was quantified.
  Grant number：15H04030
• Study on characteristics change and its mechanism of cementitious materials exposed to 60-80 degrees C　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 01 Apr. 2013 - 31 Mar. 2016
  ASAMOTO Shingo; KURAHIGE Isao; NAWA Toyoharu, Saitama University
  Grant amount(Total)：17420000, Direct funding：13400000, Indirect funding：4020000
  In this study, mechanical properties such as compressive strength and chemical degradation of cementitious materials exposed to 60-80 °C was examined. As a result, history of 80 °C during the curing can retard the strength development comparing to 20 °C curing case based on the pore structure change. It was also found that the cement with limestone powder is more probable to cause a map cracking on the surface of cementitious materials when they are exposed to high temperature at early ages. It is suggested that the replacement of cement with fly ash can be effective to inhibit the chemical degradation and to avoid the large strength reduction depending on the aggregate type.
  Grant number：25289130
• Long-Term Dynamic Simulation of Large-Scale RC-PC Infrastructures Based on Quasi Thermo-hygral Modeling　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S), Grant-in-Aid for Scientific Research (S), 01 Apr. 2011 - 31 Mar. 2016
  MAEKAWA KOICHI; ISHIDA Tetsuya; ISHIHARA Takeshi; MISHIMA Tetsuya; ISHIBASHI Tadayoshi; TANABE Shigeru; SAKATA Noboru, The University of Tokyo
  Grant amount(Total)：224640000, Direct funding：172800000, Indirect funding：51840000
  By coupling micro-pore networks with nano-channel hydraulics, the hygral-mechanical model on thermodynamic equilibrium of moisture and momentum is upgraded. Rapid adsorption of rain and following evaporation can be accurately reproduced and the model is verified by the continuous monitoring of internal moisture and curvature of the box PC mockups exposed to natural environment. Long-term varying natural frequency of tall buildings and nuclear facilities is successfully simulated by the thermo-hygral model. Delayed shear failure of underground RC culverts was also simulated by the on-site existing facilities, and the remaining risk of failure can be estimated. A unified poro-mechanics with ASR silica & corrosion gels and condensed-ice is established with strong full coupling. Based upon the simulation platform as mention above, the complex deterioration of RC bridge decks under fatigue loads and ASR & freeze/thawing cycles is investigated and the strong coupling is fairly predicted.
  Grant number：23226011
• Analysis of deleterious gas leakage risk in injection well and development of high performance oil cement　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, 01 Apr. 2013 - 31 Mar. 2015
  ASAMOTO Shingo; OSADA Msahiko, Saitama University
  Grant amount(Total)：3900000, Direct funding：3000000, Indirect funding：900000
  This study focused on the development of the well cement which has a high resistance to harmful gas leakage in Carbon dioxide Captured and Storage (CCS) and Steam Assisted Gravity Drainage (SAGD) projects; CCS is a technology to reduce CO2 emission from power plant and factory by injecting CO2 into a couple of 1000m deep ground and SAGD is a heavy oil recovery technology to reduce heavy oil viscosity by the injection of hot steam and extract it from underground. As a result, it is experimentally found that the addition of fly ash and silica fume in oil well cement can be effective for the inhibition of mechanical deterioration and gas leakage. It is also suggested that the polymer may inhibit the chemical deterioration due to the CO2 in CCS project.
  Grant number：25630182
• Mechanism of damage-induced local damping and structural health monitoring of bridges based on damping change　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), 01 Apr. 2011 - 31 Mar. 2015
  YAMAGUCHI Hiroki; MATSUMOTO Yasunao; OKUI Yoshiaki; ASAMOTO Shingo; MUTSUYOSHI Hiroshi, Saitama University
  Grant amount(Total)：42250000, Direct funding：32500000, Indirect funding：9750000
  Damages (such as tension crack, corrosion and partial fracture) and damage –induced local damping increment in steel member, concrete member and steel-concrete interface are first experimentally studied to discuss the mechanism of local damping increased by local damages. The evaluation method of structural health condition for steel, RC and PC bridges is then proposed by developing a hybrid method of experimental and analytical modal syntheses based on ambient vibration measurement and global damping change monitoring. The method of ambient vibration measurement is carefully studied for optimizing it as a system and the identification of global damping change in bridges is refined with FE model updating method. How to implement the proposed method of bridge health evaluation to the Bridge Management System was finally discussed.
  Grant number：23246082
• Reduction of Chloride Ion in RC Structures by Inverse Diffusion Method　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, 01 Apr. 2012 - 31 Mar. 2014
  MUTSUYOSHI Hiroshi; ASAMOTO Shingo, Saitama University
  Grant amount(Total)：3640000, Direct funding：2800000, Indirect funding：840000
  Chloride ingress in Reinforced Concrete (RC) structures is the most aggressive phenomenon that causes the corrosion of steel reinforcement bars and warrants untimely expensive repair of the existing structures. To ensure the durability of RC structures, the development of high performing repairing material is immensely expected. This study was carried out using ion-exchange resin admixture to develop a high durable resin mixed cement mortar for reducing the chloride induced corrosion of RC structures. A set of experiments including immersion tests, inverse diffusion tests were conducted to investigate the chloride absorption behavior and corrosion reducing potentiality of resin mixed cement mortar. The test results revealed that, newly developed mortar could effectively reduce chloride concentration at the reinforcement area and restrain the chloride induced corrosion of RC structures.
  Grant number：24656266
• Development of Rational Design Method of RC and Steel-Concrete Hybrid Structures considering Local Creep Deformation between Concrete and Steel　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), 2011 - 2013
  MAKI Takeshi; ASAMOTO Shingo, Saitama University
  Grant amount(Total)：5330000, Direct funding：4100000, Indirect funding：1230000
  In the investigation on the shrinkage cracks of concrete, the tensile stress and tensile creep strain measured in concrete specimens with and without deformed bar showed different tendencies and the influence of time-dependency in bond behavior between concrete and deformed bar was clarified. By conducting the finite element analysis of underground RC structure-soil system, the active soil pressure reduction due to creep deformation of side wall and the possibility of reduction of wall thickness and reinforcement amount were clarified, which may lead to the rational design of underground RC structures. Furthermore, the influence of sustained shear and compression forces on the deformation of joint connection with stud shear connector in steel-concrete hybrid structures was quantitatively clarified.
  Grant number：23560563
• Development of risk management system for long-term stability of cementitious materials in important structures at deep underground　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A), Grant-in-Aid for Young Scientists (A), 2011 - 2012
  ASAMOTO Shingo; KURASHIGE Isao; OKAZAKI Shinichiro; BRUNO Capra; OLIVIER POUPARD; YVI LE GUEN, Saitama University
  Grant amount(Total)：28080000, Direct funding：21600000, Indirect funding：6480000
  In this study, the risk of CO_2 leakage through the well for Carbon Captured and Storage and the long-term performance of artificial cement barrier in the facility of nuclear waste disposal are numerically and experimentally analyzed. The leakage risk is examined focusing on the cracking of cement paste in the well due to CO_2 injection pressure and the chemical deterioration of the cement paste exposed to high temperature, high pressure and high concentration of CO_2 at deep underground. The calcium leaching to increase the risk of radioactive nuclide leakage is investigated using previous numerical models to deliberate dominant parameters for the leaching.
  Grant number：23686063
• Technological development for reducing shrinkage cracking in cold climates　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 2010 - 2012
  NAWA Toyoharu; KURUMISAWA Kiyofumi; ASAMOTO Singo, Hokkaido University
  Grant amount(Total)：17030000, Direct funding：13100000, Indirect funding：3930000
  For technological development of shrinkage cracking suppression in cold climates, we have elucidated the frost damage degradation mechanisms and drying shrinkage reduction of shrinkage reducing agent, and developed a new shrinkage reducing agent (SRA) with improved freeze-thaw resistance. In addition, our shrinkage reducing agents had been optimized the molecular structure of shrinkage reducing agent according to an integrated model for the freezing and thawing action deterioration and drying shrinkage. In laboratory we examined the properties of fresh and hardened concrete such as workability, setting, mechanical properties, drying shrinkage, carbonation, rebar corrosion and the freeze-thaw resistance, and confirmed that the properties of SRA concrete were equivalent to those of concrete without SRA. Finally, we had also manufactured SRA concrete at ready-mixed concrete plant and fabricated in the actual structures, and confirmed that the performance of SRA concretes satisfied the target requirements.
  Grant number：22360220
• 塩化物イオン吸着材を繊維に取り組んだ高耐久繊維補強コンクリートの開発　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, Grant-in-Aid for Challenging Exploratory Research, 2009 - 2010
  Saitama University
  Grant amount(Total)：3100000, Direct funding：3100000
  Grant number：21656110
• Development of shrinkage cracking assessment system of concrete containing mineral admixture　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), 2009 - 2010
  ASAMOTO Shingo, Saitama University
  Grant amount(Total)：4420000, Direct funding：3400000, Indirect funding：1020000
  The comprehensive experimental study for the assessment of the shrinkage cracking of concrete with industrial waste such as blast furnace slag and fly ash is carried out. The experimental results suggest that the shrinkage cracking resistance after curing at elevated temperature is likely to be decreased due to reductions of tensile creep and tensile strength when the mineral admixture is replaced with cement, while the dense pore structure arising from the promoted chemical reaction under high temperature can mitigate the shrinkage. It is significant to take into account the effect of temperature history of concrete with mineral admixture to predict the shrinkage cracking.
  Grant number：21760342
• Shear Cracks of Prestressed Reinforced Concrete Members　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), 2007 - 2008
  MUTSUYOSHI Hiroshi; MAKI Takeshi; ASAMOTO Shingo; HA Minh, Saitama University
  Grant amount(Total)：11830000, Direct funding：9100000, Indirect funding：2730000
  Grant number：19360199
• Development of model to predict deterioration of concrete structuresb ased on actual environmental conditions　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), 2007 - 2008
  ASAMOTO Shingo, Saitama University
  Grant amount(Total)：3660000, Direct funding：3300000, Indirect funding：360000
  Grant number：19760301
• 微視的機構に立脚したコンクリート材料の時間依存構成モデルの構築　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows, Grant-in-Aid for JSPS Fellows, 2003 - 2005
  The University of Tokyo
  Grant amount(Total)：2400000, Direct funding：2400000
  Grant number：03J52271
• コンクリート工学　　　　　　　　　　　　　　　
  Competitive research funding
• Concrete Engineering　　　　　　　　　　　　　　　
  Competitive research funding