大坍落度混凝土CRCP早期开裂风险数值模拟分析  

Numerical Simulation Analysis of Early Cracking Risk of High Slump Concrete CRCP

作　　者：程小亮 余时清 秦苗 李盛[2] 孙煜 CHENG XiaoLiang;YU ShiQing;QIN Miao;LI Sheng;SUN Yu(MCC Southern City Construction Engineering Technology Co.Ltd.,Wuhan 430063,China;Key Laboratory of Special Environment Road Engineering of Hunan Province,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]中冶南方城市建设工程技术有限公司,武汉430063 [2]长沙理工大学特殊环境道路工程湖南省重点实验室,长沙410114

出　　处：《武汉理工大学学报（交通科学与工程版）》2023年第5期915-921,共7页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：国家重点研发计划项目(2021YFB2601000);湖南省自然科学基金(2022JJ30598)。

摘　　要：采用ABAQUS进行低温季节和不同环境相对湿度条件下的温湿场与应力场分析,判断CRCP结构的早期开裂风险,研究了配筋参数对CRCP路面裂缝扩展的影响.结果表明:在养护的前13 h内CRCP结构整体温度不断升高,路面板温度的振荡周期与环境温度变化周期一致.随着龄期的增长,路面由单一放热状态变为随环境温度变化的周期性放热、吸热交替作用,各深度处温度峰值逐渐减小且趋于稳定.在两种环境湿度条件下,养护前期路面结构各深度均处于较高湿度状态并随着龄期的增长湿度逐渐减小,路面结构对环境湿度的敏感程度随着路面深度的增加依次降低.环境湿度过小对路面受力有不利影响,CRCP产生最大拉应力的不利位置为路表中部.根据开裂风险曲线分析数据,在温度应力和湿度应力的综合作用下,整个养护期间CRCP结构均具有一定的开裂风险,其中26 h龄期左右开裂风险较大.在温度应力作用下,配筋率、纵筋的弹性模量、钢筋与混凝土的黏结强度等因素影响混凝土板端部的变形与混凝土最大拉应力,并进一步影响混凝土裂缝的扩展.ABAQUS was used to analyze the temperature,humidity and stress fields in low temperature season and under different environmental relative humidity conditions.The early cracking risk of CRCP structure was judged,and the influence of reinforcement parameters on crack propagation of CRCP pavement was studied.The results show that the overall temperature of CRCP structure increases continuously in the first 13 hours of curing,and the oscillation period of pavement slab temperature is consistent with the change period of ambient temperature.With the increase of age,the road surface changes from a single heat release state to a periodic heat release and heat absorption alternating with environmental temperature,and the temperature peak value at each depth gradually decreases and tends to be stable.Under two kinds of environmental humidity conditions,the depth of pavement structure is in a high humidity state in the early stage of maintenance,and the humidity gradually decreases with the increase of age,and the sensitivity of pavement structure to environmental humidity decreases with the increase of pavement depth.Too low ambient humidity has an adverse effect on pavement stress,and the unfavorable position where CRCP produces the maximum tensile stress is the middle of pavement surface.According to the analysis data of cracking risk curve,under the comprehensive action of temperature stress and humidity stress,CRCP structure has certain cracking risk during the whole curing period,and the cracking risk is greater at about 26 hours.Under the action of temperature stress,factors such as reinforcement ratio,elastic modulus of longitudinal reinforcement and bond strength between reinforcement and concrete affect the deformation of concrete slab end and the maximum tensile stress of concrete,and further affect the expansion of concrete cracks.

关 键 词：CRCP 大坍落度混凝土 温度场 湿度场 早期开裂 

分 类 号：U416[交通运输工程—道路与铁道工程]