Introduction
Dr. Ippei Maruyama is a Professor of Graduate School of Engineering at The University of Tokyo (cross-appointment) and a Professor of Graduate School of Environmental Studies at Nagoya University. He earned his B.Eng. in 1998, M.Eng. in 2000 and Dr.Eng. in 2003 from The University of Tokyo. Before he joined Nagoya University, he was visiting researcher at Delft University of Technology and assistant professor at Hiroshima University. He became a professor in 2016 in Nagoya University, then joined the University of Tokyo as a Professor.
He is a past chair of international committee on irradiated concrete, a Bureau member of RILEM, the editor in chief of Journal of Advanced Concrete Technology, and an associate editor of Materials and Structures. He is leading several national projects relating to aging management of concrete structures in nuclear power plants, Fukushima daiichi decommissioning process, and a long-term use of concrete structures.
His current research topics include architectural engineering, building material engineering, design of concrete structures, aging management of concrete structures, preservation of historical buildings and civil structures, radiation physics and chemistry for concrete, cement chemistry, applied geochemistry (mainly calcite and ferrite concretion phenomena).
Awards:
- 2020 Journal of Advanced Concrete Technology, The outstanding paper of the year
Hydrogen Production and the Stability of Hardened Cement Paste under Gamma Irradiation - 2019 Japan Concrete Institute Award (Research paper division)
Impact of Drying on Structural Performance of Reinforced Concrete Shear Walls - 2018 Journal of Advanced Concrete Technology, The outstanding paper of the year
Impact of Drying on Structural Performance of Reinforced Concrete Shear Walls - 2018 Japan Concrete Institute Award (Research paper division)
Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation - 2017 Journal of Advanced Concrete Technology, The outstanding paper of the year
Development of Soundness Assessment Procedure for Concrete Members Affected by Neutron and Gamma-Ray Irradiation - 2017 Japan Concrete Institute Award (Research paper division)
Action Mechanisms of Shrinkage Reducing Admixture in Hardened Cement Paste - 2017 Japan Concrete Institute Award (Research paper division)
A numerical model for concrete strength change under neutron and gamma-ray irradiation - 2016 Journal of Advanced Concrete Technology, The outstanding paper of the year
1) A numerical model for concrete strength change under neutron and gamma-ray irradiation
2) Action Mechanisms of Shrinkage Reducing Admixture in Hardened Cement Paste - 2016 Japan Concrete Institute Award (Research paper division)
Numerical Approach towards Aging Management of Concrete Structures [Paper 1, Paper 2] - 2015 Journal of Advanced Concrete Technology, The outstanding paper of the year
Numerical Approach towards Aging Management of Concrete Structures: Material Strength Evaluation in a Massive Concrete Structure under One-Sided Heating - 2013 The Young Scientists’ Prize, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology, Japan
Volume change mechanism of cement-based materials. - 2012 The Prize of AIJ (Architectual institute of Japan) 2012, Research Theses Division
Water-related reaction, transfer, and volume change in concrete. - 2010 JCA (Japan Cement Association) : The best paper award
Deformation of cement paste in early age
(with Mr. A. Teramoto) - 2010 JCA (Japan Cement Assocation) : The best presentation award
IR-adsorption of C-S-H under drying process - 2010 Best paper in the category of Scientific Value at Sixth International Conference Concrete under Severe Conditions
Quantification of water penetration into concrete through cracks to rebars by neutron radiography.
(with Assoc. Prof. M. Kanematsu, Ms. N. Tsuchiya, Assoc. Prof. T. Noguchi) - 2009 JCA (Japan Cement Association) : The best paper award
Visualization and analysis of water behavior around cracking of concrete by Neutron Radiography. - 2009 JCI Annual Convention: Paper Encouragement Prize
Evaluation of crack width in massive reinforced concrete structures. - 2007 AIJ (Architectural Institute of Japan): Encouragement Prize
Hydration Model of Portland Cement. - 2006 ACF: “Best Concrete Technology” Award
Study on the Application of Low-quality Recycled Coarse Aggregate to Concrete Structure by Surface Modification Treatment.
(M.Tsujino, Assoc. Prof. T. Noguchi, M. Tamura, M. Kanematsu, I. Maruyama, H. Nagai) - 2006 JCI (Japan Concrete Institute): Award for promising researcher
Modeling of early age concrete based on a hydration model. - 2005 Yamada prize, The Maeda Engineering Foundation
Time depenedent property of cement based materials on the basis of micro-mechanics. - 2003 JCI Annual Convention: Paper Encouragement Prize
Running projects
(UT＋NU) Multi-scale research on impact of drying on mechanical performance of cement based materials and their structures.
Real size structural analysis 
RC member experiment 
RC member experiment 
Team work is important! 
Micro-scale analysis 
Numerical analysis
Funded projects:
- JSPS-KAKENHI (18H03804) “Mechanism of moisture transport in cement based materials under the first desorption” (FY2018 – 2022)
- JSPS-KAKENHI (15H04077 ) “Durability mechanics of concrete structure based on nano-atomic scale alteration of C-S-H” (FY2015-2017)
- JSPS-KAKENHI (26630254) “Control of aging of C-S-H by using nano-scale materials” (FY 2014 – 2015)
- JSPS-KAKENHI (19H00791) “Structural performance change in RC buildings due to drying” (project head: Prof. Masaomi Teshigawara) (FY2019-2022)
- Ministry of Land, Infrastructure, Transport and Tourism, Building Standards Law Expanding Research S30, “Study on Evaluation Method of Vibration Damping of Buildings for Improvement of Calculation Accuracy of Response Displacement in Limit Strength Calculation of Reinforced Concrete Structures” (project head: Prof. Masaomi Teshigawara)
- Collaboration research with Navier, Ecole des Ponts, CNRA and LafargeHolcim (FY2015-2018)
Related papers:
- I. Maruyama, T. Ohkubo, T. Haji, R. Kurihara, Reply to Zhou et al.’s “A discussion of the paper ‘Dynamic microstructural evaluation of hardened cement paste during first drying monitored by 1H NMR relaxometry,’” Cem. Concr. Res. 137 (2020) 106219. doi:10.1016/J.CEMCONRES.2020.106219.
- P. Suwanmaneechot, A. Aili, I. Maruyama, Creep behavior of C-S-H under different drying relative humidities: Interpretation of microindentation tests and sorption measurements by multi-scale analysis, Cem. Concr. Res. 132 (2020) 106036, 6ps. doi:10.1016/j.cemconres.2020.106036.
- R. Kurihara, I. Maruyama, Effects of heating and drying on the strength and stiffness of high-early-strength Portland cement pastes, Cem. Concr. Compos. 106 (2020) 103455, 10ps. doi:10.1016/j.cemconcomp.2019.103455.
- H. Sasano, I. Maruyama, Numerical study on the shear failure behavior of RC beams subjected to drying, Nucl. Eng. Des. 351 (2019) 203–211. doi:10.1016/j.nucengdes.2019.06.003.
- I. Maruyama, J. Rymeš, Temperature dependency of short-term length-change and desorption isotherms of matured hardened cement, J. Adv. Concr. Technol. 17 (2019) 188–194. doi:10.3151/jact.17.5.188.
- I. Maruyama, T. Ohkubo, T. Haji, R. Kurihara, Dynamic microstructural evolution of hardened cement paste during first drying monitored by 1H NMR relaxometry, Cem. Concr. Res. 122 (2019) 107–117. doi:10.1016/j.cemconres.2019.04.017.
- H. Sasano, I. Maruyama, A. Nakamura, Y. Yamamoto, M. Teshigawara, Impact of drying on structural performance of reinforced concrete shear walls, J. Adv. Concr. Technol. 16 (2018) 210–232. doi:https://doi.org/10.3151/jact.16.210.
- I. Maruyama, E. Gartner, K. Beppu, R. Kurihara, Role of alcohol-ethylene oxide polymers on the reduction of shrinkage of cement paste, Cem. Concr. Res. 111 (2018) 157–168. doi:10.1016/j.cemconres.2018.05.017.
- I. Maruyama, J. Rymeš, M. Vandamme, B. Coasne, Cavitation of water in hardened cement paste under short-term desorption measurements, Mater. Struct. Constr. 51 (2018). doi:10.1617/s11527-018-1285-x.
- E. Gartner, I. Maruyama, J. Chen, A new model for the C-S-H phase formed during the hydration of Portland cements, Cem. Concr. Res. 97 (2017) 95–106. doi:10.1016/j.cemconres.2017.03.001.
- I. Maruyama, H. Sasano, M. Lin, Impact of aggregate properties on the development of shrinkage-induced cracking in concrete under restraint conditions, Cem. Concr. Res. 85 (2016) 82–101. doi:10.1016/j.cemconres.2016.04.004.
- I. Maruyama, N. Sakamoto, K. Matsui, G. Igarashi, Microstructural changes in white Portland cement paste under the first drying process evaluated by WAXS, SAXS, and USAXS, Cem. Concr. Res. 91 (2016) 24–32. doi:http://dx.doi.org/10.1016/j.cemconres.2016.10.002.
- I. Maruyama, K. Beppu, R. Kurihara, A. Furuta, Action mechanisms of shrinkage reducing admixture in hardened cement paste, J. Adv. Concr. Technol. 14 (2016) 311–323. doi:10.3151/jact.14.311.
- I. Maruyama, Multi-scale review for possible mechanisms of natural frequency change of reinforced concrete structures under an ordinary drying condition, J. Adv. Concr. Technol. 14 (2016) 691–705. doi:10.3151/jact.14.691.
- I. Maruyama, G. Igarashi, Y. Nishioka, Bimodal behavior of C-S-H interpreted from short-term length change and water vapor sorption isotherms of hardened cement paste, Cem. Concr. Res. 73 (2015) 158–168. doi:10.1016/j.cemconres.2015.03.010.
- I. Maruyama, H. Sasano, Strain and crack distribution in concrete during drying, Mater. Struct. Constr. 47 (2014) 517–532. doi:10.1617/s11527-013-0076-7.
- I. Maruyama, H. Sasano, Y. Nishioka, G. Igarashi, Strength and Young’s modulus change in concrete due to long-term drying and heating up to 90 °C, Cem. Concr. Res. 66 (2014) 48–63. doi:10.1016/j.cemconres.2014.07.016.
- I. Maruyama, Y. Nishioka, G. Igarashi, K. Matsui, Microstructural and bulk property changes in hardened cement paste during the first drying process, Cem. Concr. Res. 58 (2014) 20–34. doi:10.1016/j.cemconres.2014.01.007.
- I. Maruyama, Origin of drying shrinkage of hardened cement paste: Hydration pressure, J. Adv. Concr. Technol. 8 (2010) 187–200. doi:10.3151/jact.8.187.
(UT+NU）Natural/Artificial carbonate-concretion formation
Escalante 
Escalante 
White cliff 
Miyazaki 
Miyazaki 
Fe-concretion 
Moqui marble 
Precursor of Moqui marble 
Similarity of the precursors and Moqui marbles
Funding projects:
- NEDO: C4S project (Calcium carbonate concrete system for sustainability), PJ3 technical lead (FY2020-2022)
- JSPS-KAKENHI (18H03893) Application of natural calcium carbonate concretion for occlusion (Project leader: Prof. H. Yoshida, FY2018 – 2021 )
- JSPS-KAKENHI (15H04224) Application of natural calcium carbonate concretion for occlusion (Project leader: Prof. H. Yoshida, FY2015 – 2018)
- JSPS-KAKENHI (15H05227) Applied geo-scientific field study on Fe-concretion and multi-species ion transfer (Project leader: Prof. H. Yoshida, FY2015 – 2017 )
- JSPS-KAKENHI (26630464) Natural analogue of occlusion of cracking due to carbonate concretion (Project leader: Prof. H. Yoshida, FY2014-2017)
Relevant papers:
- H. Yoshida, H. Hasegawa, N. Katsuta, I. Maruyama, S. Sirono, M. Minami, Y. Asahara, S. Nishimoto, Y. Yamaguchi, N. Ichinnorov, R. Metcalfe, Fe-oxide concretions formed by interacting carbonate and acidic waters on Earth and Mars, Sci. Adv. 4 (2018). doi:10.1126/sciadv.aau0872.
- H. Yoshida, A. Ujihara, M. Minami, Y. Asahara, N. Katsuta, K. Yamamoto, S.I. Sirono, I. Maruyama, S. Nishimoto, R. Metcalfe, Early post-mortem formation of carbonate concretions around tusk-shells over week-month timescales, Sci. Rep. 5 (2015) 1–7. doi:10.1038/srep14123.
(NU) Concrete degradation under neutron and gamma-ray irradiation environments
PIE HOT facility in IFE 
JEEP II reactor 
JEEP II reactor 
Capsule factory 
Capsule design
Funded projects:
– Evaluation of soundness of concrete subjected to irradiation based on mechanism of metamictization of rock-forming minerals,
Funded by METI, collaboration with Mitsubishi Research Institute, Nagaoka University of Technology, Mitsubishi Research Associates, Kajima Corporation, UJV-REZ, and so on. (FY2017-2022)
Relevant papers:
- Sasano, H., Maruyama, I., Sawada, S., Ohkubo, T., Murakami, K. and Suzuki, K., (2020). “Meso-Scale Modelling of the Mechanical Properties of Concrete Affected by Radiation-Induced Aggregate Expansion.”,Journal of Advanced Concrete Technology. Japan Concrete Institute, 18(10), pp. 648–677, doi: 10.3151/jact.18.648.
- Kambayashi, D., Sasano, H., Sawada, S., Suzuki, K. and Maruyama, I., (2020). “Numerical Analysis of a Concrete Biological Shielding Wall under Neutron Irradiation by 3D RBSM.”,Journal of Advanced Concrete Technology. Japan Concrete Institute, 18(10), pp. 618–632, doi: 10.3151/jact.18.618.
- V.N. Luu, K. Murakami, H. Samouh, I. Maruyama, K. Suzuki, P. Prak Tom, L. Chen, S. Kano, H. Yang, H. Abe, M. Suzuki, Swelling of alpha-quartz induced by MeV ions irradiation: Critical dose and swelling mechanism, J. Nucl. Mater. 539 (2020) 152266. doi:10.1016/j.jnucmat.2020.152266.
- S. Ishikawa, I. Maruyama, M. Takizawa, J. Etoh, O. Kontani, S. Sawada, Hydrogen production and the stability of hardened cement paste under gamma irradiation, J. Adv. Concr. Technol. 17 (2019) 673–685. doi:10.3151/jact.17.673. (JACT outstanding paper 2019)
- I. Maruyama, S. Ishikawa, J. Yasukouchi, S. Sawada, R. Kurihara, M. Takizawa, O. Kontani, Impact of gamma-ray irradiation on hardened white Portland cement pastes exposed to atmosphere, Cem. Concr. Res. 108 (2018) 59–71. doi:10.1016/j.cemconres.2018.03.005.
- I. Maruyama, O. Kontani, M. Takizawa, S. Sawada, S. Ishikawa, J. Yasukouchi, O. Sato, J. Etoh, T. Igari, Development of soundness assessment procedure for concrete members affected by neutron and gamma-ray irradiation, J. Adv. Concr. Technol. 15 (2017) 440–523. doi:10.3151/jact.15.440. (JACT outstanding paper 2017)
- I. Maruyama, K. Haba, O. Sato, S. Ishikawa, O. Kontani, M. Takizawa, A numerical model for concrete strength change under neutron and gamma-ray irradiation, J. Adv. Concr. Technol. 14 (2016) 144–163. doi:10.3151/jact.14.144. (JACT outstanding paper 2016)
- I. Maruyama, S. Muto, Change in relative density of natural rock minerals due to electron irradiation, J. Adv. Concr. Technol. 14 (2016) 706–716. doi:10.3151/jact.14.706.
- I. Maruyama, G. Igarashi, Numerical approach towards aging management of concrete structures: Material strength evaluation in a massive concrete structure under one-sided heating, J. Adv. Concr. Technol. 13 (2015) 500–527. doi:10.3151/jact.13.500.
- G. Igarashi, I. Maruyama, Y. Nishioka, H. Yoshida, Influence of mineral composition of siliceous rock on its volume change, Constr. Build. Mater. 94 (2015) 701–709. doi:10.1016/j.conbuildmat.2015.07.071.
(NU) Enhancement of soundness evaluation for concrete structures and members by using the data harvested from decommissioning nuclear power plants
Funded projects:
- Soundness evaluation of concrete members phase I, collaboration with Chube electric company (FY2017-2019)
- Soundness evaluation of concrete members phase II, collaboration with Chube electric company (FY2020-2023)
Relevant papers:
- Maruyama, I., Rymeš, J., Aili, A., Sawada, S., Kontani, O., Ueda, S. and Shimamoto, R., (2021). “Long-term use of modern Portland cement concrete: The impact of Al-tobermorite formation.”,Materials & Design. Elsevier, 198, p. 109297, doi: 10.1016/j.matdes.2020.109297.
- J. Rymeš, I. Maruyama, R. Shimamoto, A. Tachibana, Y. Tanaka, S. Sawada, Y. Ichikawa, O. Kontani, Long-term material properties of a thick concrete wall exposed to ordinary environmental conditions in a nuclear reactor building: The contribution of cement hydrates and feldspar interaction, J. Adv. Concr. Technol. 17 (2019) 195–215. doi:10.3151/jact.17.5.195.
- Y. Ichikawa, I. Maruyama, H. Wada, K. Yokokura, S. Ishikawa, G. Saito, Soundness evaluation method for concrete structures based on the data obtained from decommissioning Hamaoka nuclear power plant, Part 3: Investigation on core sampling method, Proceeding Annu. Conf. of AIJ. Structure (2017) 1259–1260.
- K. Yokokura, H. Wada, O. Kontani, I. Maruyama, Concrete strength evaluation of massive concrete structures based on the data obtained from decommissioning nuclear power plant, 24th Int. Conf. Struct. Mech. React. Technol. SMiRT-24,. (2017) 209–218.Maruyama, I., Rymeš, J., Aili, A., Sawada, S., Kontani, O., Ueda, S. and Shimamoto, R., (2021). “Long-term use of modern Portland cement concrete: The impact of Al-tobermorite formation.”,Materials & Design. Elsevier, 198, p. 109297, doi: 10.1016/j.matdes.2020.109297.
- J. Rymeš, I. Maruyama, R. Shimamoto, A. Tachibana, Y. Tanaka, S. Sawada, Y. Ichikawa, O. Kontani, Long-term material properties of a thick concrete wall exposed to ordinary environmental conditions in a nuclear reactor building: The contribution of cement hydrates and feldspar interaction, J. Adv. Concr. Technol. 17 (2019) 195–215. doi:10.3151/jact.17.5.195.
- Y. Ichikawa, I. Maruyama, H. Wada, K. Yokokura, S. Ishikawa, G. Saito, Soundness evaluation method for concrete structures based on the data obtained from decommissioning Hamaoka nuclear power plant, Part 3: Investigation on core sampling method, Proceeding Annu. Conf. of AIJ. Structure (2017) 1259–1260.
- K. Yokokura, H. Wada, O. Kontani, I. Maruyama, Concrete strength evaluation of massive concrete structures based on the data obtained from decommissioning nuclear power plant, 24th Int. Conf. Struct. Mech. React. Technol. SMiRT-24,. (2017) 209–218.
(UT) Estimation of radio-active element contamination in concrete of Fukushima Daiichi plants
- Kiran, R., Samouh, H., Igarashi, G., Haji, T., Ohkubo, T., Tomita, S. and Maruyama, I., (2020). “Temperature-Dependent Water Redistribution from Large Pores to Fine Pores after Water Uptake in Hardened Cement Paste.“,Journal of Advanced Concrete Technology. Japan Concrete Institute, 18(10), pp. 588–599, doi: 10.3151/jact.18.588.
Other papers:
- M. Nagao, K. Kobayashi, Y. Jin, I. Maruyama, T. Hibino, Ionic conductive and photocatalytic properties of cementitious materials: calcium silicate hydrate and calcium aluminoferrite, J. Mater. Chem. A. (2020) 15157–15166. doi:10.1039/D0TA04866F.
- A. Matsuda, I. Maruyama, A. Meawad, S. Pareek, Y. Araki, Reaction, phases, and microstructure of fly ash-based alkali-activated materials, J. Adv. Concr. Technol. 17 (2019) 93–101. doi:10.3151/jact.17.93.
- I. Jang, I. Maruyama, Numerical Prediction of Crack Width in Massive Concrete Member Due To Heat of Hydration, in: R. Sato (Ed.), JCI-RILEM Int. Work. “Control Crack. Mass Concr. Relat. Issues Concern. Early Age Crack. Concr. Struct., Tokyo, Japan, 2017: pp. 91–100.
- T. HAJI, S. KOTERA, R. KURIHARA, I. MARUYAMA, Impact of Demolding Age and Mineral Composition of Cement on Drying Shrinkage of Cement Paste, Proc. Japan Concr. Inst. 38 (2016) 45–50.
- I. Maruyama, A. Teramoto, G. Igarashi, Strain and thermal expansion coefficients of various cement pastes during hydration at early ages, Mater. Struct. 47 (2014) 27–37. doi:10.1617/s11527-013-0042-4.
- I. Maruyama, A. Teramoto, Effect of water-retaining lightweight aggregate on the reduction of thermal expansion coefficient in mortar subject to temperature histories, Cem. Concr. Compos. 34 (2012) 1124–1129. doi:10.1016/j.cemconcomp.2012.08.003.
- I. Maruyama, M. Suzuki, R. Sato, Stress distribution and crack formation in full-scaled ultra-high strength concrete columns, Mater. Struct. Constr. 45 (2012) 1829–1847. doi:10.1617/s11527-012-9873-7.
- I. Maruyama, N. Kishi, K. Kawase, Measurement of water content in hardened cement paste using terahertz radiation, J. Struct. Constr. Eng. 75 (2010) 1073–1079. doi:10.3130/aijs.75.1073.