高强混凝土徐变力学实验研究

Experimental Study of Creep Mechanics for High Strength Concrete

为掌握苏通大桥连续刚构桥所用C60高强混凝土的徐变性能,开展了自然环境下配筋高强混凝土的徐变力学试验。为获得徐变试验所需75t的加载力,设计并制造出95t的徐变加载装置,解决了混凝土徐变试验大吨位加载的问题。针对应变测试过程中温度变化对应变测试的影响作了深入的探讨,提出了应变计温度影响的修正方法。通过试验结果与现行桥规JTG D62-2004的比较得出:配筋高强混凝土徐变系数远小于规范取值,且在170天后徐变系数有收敛的特征。试验结果说明,实桥所用C60高强混凝土的徐变可以满足桥梁对混凝土耐久性的要求。

In order to obtain creep properties of high strength concrete （HSC） used in Sutong continuous rigid-frame bridge, creep experiment of reinforced high strength concrete was carried out under natural environment. To obtain 75-ton loading force for creep experiment, a 95-ton creeploading device was designed and manufactured, which solve the large-tonnage loading problem in concrete creep experiment. The temperature effect on concrete strain gauge was analyzed and the temperature correction method of strain gauge was also presented. The measured values of creep coefficient are far less than that of current bridge code （JTG D62-2004）, and it has the characteristics of convergence after 170 days. Results show that the creep of HSC C60 used in the real bridge can satisfy the requirements for concrete durability.