梯度热开裂-蒸汽压-荷载耦合作用下高性能混凝土缺陷演化研究

项目名称： 梯度热开裂-蒸汽压-荷载耦合作用下高性能混凝土缺陷演化研究

项目编号： No.51478290

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑环境与结构工程学科

项目作者： 杜红秀

作者单位： 太原理工大学

项目金额： 86万元

中文摘要： 高性能混凝土的高温损伤是一个多因素作用的复杂的非线性问题，是改善材料性能、提高结构抗火能力及灾后损伤评估的瓶颈与难点，而揭示其高温梯度热开裂-蒸汽压-荷载耦合作用下内部损伤缺陷和性能劣化发生的本质规律和机理是解决该难题的关键。本项目拟对高性能混凝土进行X射线CT三维动态显微观测、扫描电镜观测、压汞测试、孔隙水蒸汽压测试以及热变形测试，研究混凝土内部微结构损伤特征、缺陷演化规律；建立基于浆体基质和骨料热变形不匹配引发的热开裂随温度演化的模型；引入侵彻理论和空腔膨胀理论，建立不同形状缺陷蒸汽压作用下的劣化演化模型；基于弹塑性力学和材料科学理论，根据能量守恒原理，采用有效的无网格分析方法，对热开裂-蒸汽压-荷载耦合作用下混凝土损伤缺陷演化规律进行模拟研究；建立兼顾外界作用和材料自身演化的高性能混凝土的高温损伤理论体系，为促进混凝土抗火及其损伤评估研究的发展提供实验和理论依据。

中文关键词： 高性能混凝土；梯度热开裂；蒸汽压；耦合；缺陷演化

英文摘要： Abstract：Being a complicated nonlinear problem influence by many factors, the damage caused by high-temperature to High Performance Concrete (HPC), has been the critical point for the improvement of material performance, enhancement of structure fire resistance, and damage assessment after disaster. The key issues of the problem are the essential rules and mechanisms of the damage and performance degradation occurred in HPC under the coupling of thermal cracking-vapor pressure -load action under high temperature gradient. In this project, the microstructure damage characteristics and defect evolution in HPC after high temperature gradient will be systematically investigated by X-ray, CT three-dimensional dynamic microscopy, scanning electron microscopy observation, mercury injection, testing pore water vapor pressure and thermal deformation test, the evolution model of thermal cracking with temperature, caused by the mismatching of thermal deformation of slurry matrix and aggregate, will be established. Meanwhile, with the help of the penetration theory and empty expansion theory, the degradation evolution model under the action of vapor pressure with different shape defects will be built. Then according to the principle of energy conservation, elastic-plastic mechanics and material science theory, the damage degradation of HPC under the coupling of thermal cracking-vapor pressure-load action will be numerically investigated by the effective meshless finite element analysis method. Finally, the high temperature damage theoretical system of HPC will be established based on comprehensive consideration of external influence and internal evolution of HPC. This project will provide experimental and theoretical basis for promoting the development of research on fire resistance and damage assessment of concrete.

英文关键词： HPC;Gradient Thermal Cracking;Vapor Pressure;Coupling;Defect Evolution