泄洪洞高性能衬砌混凝土自由体积应变监测

Field Monitoring Test and Feedback on Free Volume Strain for High-Performance Concrete Lining of Spillway Tunnel

泄洪洞衬砌混凝土必须具有防冲耐磨等特性,因此常采用掺硅粉高性能混凝土。在某特大型水电工程的泄洪洞边墙衬砌混凝土中埋设无应力计进行掺硅粉高性能混凝土应变监测试验,分别采用常规最小二乘法以及无应力计测值统计模型进行掺硅粉高性能混凝土热膨胀系数和自生体积变形反演。分析表明:两种方法反演的热膨胀系数较接近,在7.5×10-6/℃左右;高性能衬砌混凝土自生体积变形呈收缩型,单调递减,后期基本稳定在-20×10-6。

Abstract ： Concrete lining of spillway tunnel must have the characteristics such as erosion prevention, abrasion resistance and so on. So high-perform- ance concrete with ganister sand is commonly used. In this paper, a strain monitoring test of the high-performance concrete had been done on a south- western hydroelectric power project, in which there was a non-stress meter in the concrete used in the spillway tunnel. During the test, two methods were adopted, which were the common method of the least square technique and the method of building a modal based on the statistical data from the non-stress meter, to get feedback of the thermal expansion coefficient and the autogenous volume deformation. The analysis shows that the thermal ex- pansion coefficients are very close to each other getting from the two methods, which are about7.5×10^6/℃. The autogenous volume deformation of the high-performance concrete has a shrinkage and monotonically decreasing and tends to be steady around -20 × 10^ -6 in the later period.