混凝土收缩徐变效应预测模型及影响因素  

Prediction model and influencing factors for concrete shrinkage and creep effects

作　　者：孟江[1,2] 赵宝俊[1,3] 刘建梅[2] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]陕西省公路勘察设计院,陕西西安710071 [3]陕西省交通建设集团公司,陕西西安710075

出　　处：《长安大学学报（自然科学版）》2013年第2期56-62,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51078306)

摘　　要：为了提前预见混凝土的收缩和徐变对结构物使用性能的影响,分别采用CEB-FIP模型、ACI模型、BP模型和GL—2000模型等方法对混凝土的收缩、徐变进行计算分析,且对相同条件下各种计算方法得出的结果进行对比。结果表明:混凝土收缩应变对构件理论厚度比较敏感,而徐变系数对构件理论厚度敏感度较小,混凝土徐变效应随着加荷龄期的增加而减小;当加荷龄期由3d增加到28d时,混凝土的的徐变效应终值减小80%左右;收缩徐变效应对环境平均相对湿度比较敏感,当环境平均相对湿度从50%升至80%时,徐变系数减小近30%,而收缩应变减小达50%,比较而言,环境相对湿度变化对混凝土收缩效应较徐变效应更大。In order to forecast the influence of concrete shrinkage and creep on the performance of structures, the CEB-FIP model, ACI model, BP model and GL--2000 model were adopted re- spectively to calculate and analyze the shrinkage and creep of concrete and the results acquired with various calculating methods were compared under identical conditions. The results show that the theoretical thickness of structures is very sensitive to shrinkage and creep of concrete, but the creep coefficient is not sensitive to theoretical thickness of structures~ the creep effect of concrete decreases with the increase of loading period~ when loading period increases from 3 days to 28 days, the final value of concrete creep effect is reduced by about 80%~ shrinkage and creep effect are very sensitive to average relative humidity of environment, when the average relative humidity of environment is enhanced from 50% to 80%, the creep effect is reduced by approxi- mately 30%, while the shrinkage effect is reduced by as much as 50% ~ comparatively, the change of environmental relative humidity imposes greater influence on shrinkage effect than on creep effect of concrete. 1 tab, 4 figs, 23 refs.

关 键 词：桥梁工程 混凝土 收缩徐变 预测模型 影响因素 

分 类 号：U414.1[交通运输工程—道路与铁道工程]