基于统计回归的钢筋与再生混凝土粘结强度分析

Analysis of Bonding Strength between Rebar and Recycled Concrete Based on Statistical Regression

为了研究钢筋与再生混凝土粘结强度,在有关钢筋与再生混凝土粘结性能试验数据统计的基础上,分析了再生混凝土抗压强度、保护层厚度、钢筋锚固长度和钢筋直径等参数对其粘结强度的影响规律;利用最小二乘法统计回归得到了钢筋与再生混凝土粘结强度的计算公式,并用该公式对钢筋再生混凝土试验数据进行了验算和对比。研究表明:随着再生混凝土抗压强度和再生混凝土保护层相对厚度的增大,钢筋与再生混凝土粘结强度呈增大趋势;钢筋与再生混凝土粘结强度随着钢筋锚固长度的增大而减小;钢筋直径钢筋直径为10 mm钢筋与再生混凝土的粘结强度略大于其他钢筋直径的粘结强度。文中提出的钢筋与再生混凝土粘结强度计算模型的计算值与基于拉拔试验实测值较为接近,预测结果较为合理。

In the purpose of researching the bond strength between reinforcing steel bar and recycled concrete,we examined the influences of parameters including compressive strength and protective layer thickness of recycled concrete as well as length of anchorage and diameter of rebar on the bonding strength according to test data of the bond performance between steel and recycled concrete.We employed the least squares method to obtain the equation of bonding strength by statistical regression and verified the equation by comparing the calculation result with test data.Result demonstrated that with the increase of compressive strength and protective layer thickness of recycled concrete,the bonding strength between rebar and recycled concrete also increased;however,with the elongation of steel anchorage length,the bonding strength reduced.The bonding strength when rebar diameter was 10 mm was larger than that of other diameters.The calculated results are close to the test results,indicating that the model presented in this paper is reasonable.