（1 湘潭大学土木工程与力学学院， 湘潭 411105； 2 东南大学土木工程学院， 南京 211189；3 湖南大学土木工程学院，  长沙  410082）

［摘要］为研究混凝土高温后质量损失及抗压强度的退化规律，对高温后混凝土立方体试件的质量损失和抗压性能进行了测试，分析了温度对混凝土的质量损失和抗压强度的影响以及高温后混凝土的受压破坏特征。研究结果表明，随着温度的升高，混凝土的质量损失逐渐增大而抗压强度整体呈下降趋势，800℃的高温作用后混凝土抗压强度基本丧失，相比于常温其损失程度高达85-4%；总体而言，混凝土抗压强度随温度升高而减小的幅度与质量损失率随温度升高而增大的幅度基本一致。通过对试验数据的拟合回归分析，建立了混凝土抗压强度与温度、质量损失率与温度及抗压强度与质量损失率之间的计算公式，可利用所提出的公式通过混凝土质量损失或受火温度来初步预估火灾后混凝土结构的剩余抗压强度。

［关键词］混凝土； 高温； 质量损失； 抗压强度

中图分类号：TU528-45文献标识码：A文章编号：1002-848X(2019)04-0076-06

Experimental study on mass loss and compressive strength degradation law of concrete after high temperature exposure

Zhang Bai1, 2, Chen Jun1, Yang Ou3, Jiang Enhao1, Ma Yu1

(1 College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, China;2 School of Civil Engineering, Southeast University, Nanjing 211189, China;3 College of Civil Engineering, Hunan University, Changsha 410082, China)

Abstract:To investigate the mass loss and compressive strength degradation law of concrete after high temperature exposure, the mass loss and compressive properties of concrete cube specimen after temperature exposure was investigated. The effect of  temperature on mass loss and compressive strength of concrete and the compression failure characteristics after temperature exposure was analyzed. The research results show that the compressive strength of concrete decreases gradually and the mass loss of concrete increases gradually with the high temperature increases. After 800℃, the compressive strength of concrete is basically vanished, which is up to 85-4% loss compared to the normal temperature. In general, the decreasing extent in the compressive strength of concrete with increase of temperature are basically consistent to that of the growth in the mass loss rate of concrete with increase of temperature. Through fitting regression analysis of test data, the formulas were established for calculating the compressive strength of concrete with temperature, calculating mass loss rate and temperature, and calculating compressive strength and mass loss rate. The formulas could be used to predict the residual compressive strength of concrete after fire through mass loss and temperature.

Keywords:concrete; high temperature; mass loss; compressive strength

*国家自然科学基金资助项目(51578229)。

作者简介：张白，博士研究生，Email:baizhang1120@126.com。