循环孔隙水对混凝土弹性应变、残余应变及损伤发展的影响  

Effect of Cyclic Pore Water on Plastic Strain and Damage Development of Concrete

作　　者：罗曦[1] 彭刚[1] 马小亮[1] 肖杰[1] 

机构地区：[1]三峡大学土木与建筑学院,443002

出　　处：《灾害与防治工程》2016年第1期39-45,共7页Disaster and Control Engineering

摘　　要：本文对混凝土进行了不同次数（0次、50次、100次、200次）的有压孔隙水循环处理，并在有水环境中直接对混凝土进行加载，加载速率恒定为10^-4／s。为了在应变空间上探究孔隙水压对混凝土内部损伤发展的影响，本文将应交分解为残余应变与弹性应变，并分别进行了分析。分析结果表明：①孔隙水对混凝土弹性应变和残余应变的影响主要集中在峰值应变之后；②Stefan效应的作用主要体现在水循环次数较少的时候；③水循环次数较少时，随着循环次数的增加，弹性应变最大值增大，塑性应变的发展滞后，混凝土脆性降低，而孔隙水循环次数达到一定量后，弹性应变最大值开始减小，塑性应变的发展开始提前，脆性开始升高。在此基础上，本文在应变空间上探究了不同工况下混凝土的损伤发展规律，以峰值应变点、弹性应变最大值点为两个临界点将混凝土的损伤发展过程划分为3个阶段。损伤分析的结果表明：在水循环次数较少时，由于Stefan效应，损伤的发展随循环次数的增加而滞后，在水循环次数达到一定值后，Stefan效应逐渐被抵消，损伤的发展开始提前。The number of concrete （0 times, 50 times, 100 times, 200 times） the pressure of pore water circulation, and in aqueous environment directly on the concrete loading, the loading rate constant is 10^-4/s. In order to study the pore water pressure in strain space in- fluence on the development of internal damage of concrete, the strain decomposition of re- sidual strain and elastic strain, and are analyzed separately. The results of the analysisshow that the pore water of concrete elastic strain and the residual strain effects are mainly concentrated in the peak strain; II Stefan effect is mainly reflected in the number of circu- lating water less; 3 water cycle number is small. With increasing number of cycles, the e- lastic strain maximum with increasing plastic strain development lags behind, the brittle- ness of concrete reduce, and gap water cycle number reach a certain amount, the elastic strain maximum began to decrease, plastic strain development began to advance, brittle be- gan to increase. On the basis of this, this paper in the strain space explores the different conditions of concrete damage evolution law, and the peak strain and elastic strain maximum point for two critical point of concrete damage development is divided into three stages. The result of damage analysis showed that the development of damage increased with the increase of the number of cycles, and the development of damage after the number of cycles reached a certain value.

关 键 词：混凝土 孔隙水压 残余应变 损伤特性 

分 类 号：TU441.8[建筑科学—岩土工程]