Modeling of Decomposition and Self-healing Processes of Hardened Cement Paste Exposed to High Temperature
In civil and building engineering, there are lots of knowledge and experience on concrete exposed to high temperature and fire.To satisfy multifaceted requirements, wider variety of cementitious composite like concrete is challenged and we also seriously have to assess these performances on serviceability as well as unusual risk such as fire.This paper aims at coupled micro-pore structure formation, decomposition and self-healing models for enabling to assess the overall quality of concrete, and main attention is directed to protection performance of concrete under fire accident.To evaluate the fire performance of concrete having different characteristics from the past, the authors intend to improve the multi-scale hygro-chemo-physics model, which is practically integrated onto a finite-element program.In this research investigated is the model of dehydration, rehydration after wet curing exposed to high temperature over 400℃.In detail, three stages are considered;1) 100℃ and more, crystallization water of AFm is decomposed depending on temperature, 2) 200℃ and more, crystallization water of C-S-H is decomposed depending on temperature, 3) 400℃ and more, de-hydration of Ca(OH)2 occurs, and the crystalized water release proceeds, 4) over 800℃, returning of dehydrated C-S-H to clinker takes place.The formation of CaO in C-S-H gels at fire is also taken into account as a high reactive material to be easily self-healed with water.Compressive strength of cement composites and other mechanical characteristics are evaluated by using the micro-pore structure based modeling which was investigated and developed at room temperature, and the versatility of the strength modeling is discussed with experimental validation.
De-hydration Re-clinker Fire damage Self-healing Thermal analysis
Keitai Iwama Natsumi Ishibashi Koichi Maekawa
Graduate School of Urban Innovation, Yokohama National University, Kanagawa-ken, Japan
国际会议
福州
英文
227-234
2018-11-04（万方平台首次上网日期，不代表论文的发表时间）