回弹-拔出综合法检测混凝土强度的试验研究

Experimental study on testing of concrete strength by rebound-pull out method

采用了本地区具有代表性的原材料,分别配制了强度等级为C10、C20、C30、C40、C50和C60近80组混凝土试验试件,进行回弹、拔出以及抗压强度试验。利用最小二乘法,选取三种不同形式的回归模型进行回归分析,建议采用复相关系数最大、平均相对误差和相对标准差最小的直线函数式作为本地区回弹-拔出综合法地方测强曲线。通过对比试验,比较综合法与单一方法推定混凝土强度值,综合法的相对误差较小,检测精度高。

According to the characteristics of concrete, using the typical raw materials of local area, the simples of C10, C20, C30, CAO, C.50, C60 for nearly 80 groups of concrete test specimens were made, and rebound, pulled out and the compressive strength values were tested. The regression equations of three different forms were given by using the Method of Minimum Squares. Compared with correlation coefficient,relative standard error and average relative error,the regression equation of liner model had the best effect and the highest accuracy. The equation was used as the local curve of rebound-pull out method. By the compared experiment, it was proved that the relative error of comprehensive method compared with single method was little. Moreover, the rebound-pull out method has high detecting precision.