自然环境混凝土徐变试验和预测模型研究  

Experimental Study and Prediction Model for Concrete Creep in Ambient Environment

作　　者：杨永清[1] 鲁薇薇[1] 李晓斌[1] 余小华[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《西南交通大学学报》2015年第6期977-983,1010,共8页Journal of Southwest Jiaotong University

基　　金：铁道部科技研究开发计划重大课题资助项目(2008G031-K)

摘　　要：为准确预测实际工程结构混凝土徐变的发展规律,在反映恒温、恒湿条件下混凝土徐变性能的基准徐变系数基础上,引入温度、湿度徐变系数,建立了预测实际环境温、湿度条件下混凝土徐变的组合徐变模型.借鉴徐变计算理论,提出了由环境温度变化引起的混凝土附加徐变的实用计算方法.研究结果表明:自然环境中随时间变化的温、湿度导致现行徐变模型的预测结果与实际的徐变变形存在显著差异,其引起的混凝土附加徐变随季节更替而产生周期性增减交替变化;组合徐变模型给出的结果与试验结果最大相对偏差为6%,与试验结果最为接近的现行徐变模型相比,减小了7%.In order to accurately predict structural concrete creep,utilizing the benchmark creep coefficient under constant temperature and humidity,temperature creep coefficient and moisture creep coefficient were introduced to develop the combination creep model for concrete exposed to the actual ambient environment. Based on creep theory,a practical method to calculate additional creep caused by variable ambient temperature was provided. The results indicate that due to the time- varying ambient temperature and relative humidity,there is a marked difference between the actual creep and model predicted creep. The additional creep is subject to seasonal cycle variation. The relative deviation between the experimental and calculated results of combination creep model is 6%,which is reduced by 7% in contrast to the closest results by the current creep model.

关 键 词：徐变 徐变预测模型 试验研究 实用计算方法 自然环境 

分 类 号：U448.33[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]