再生混凝土棱柱体与立方体抗压强度关系模型

Model for the Relationship between Prism and Cube Compressive Strengths of Recycled Aggregate Concrete

再生混凝土棱柱体与立方体抗压强度之间的关系显著异于普通混凝土,而现有模型预测精度较低、离散性较高.为此,搜集并分析了文献中139组试验数据,研究了再生骨料取代率、吸水率与二者耦合效应对再生混凝土强度的显著影响,提出了再生混凝土棱柱体与立方体抗压强度关系模型,模型预测结果变异系数仅为5.4%.为方便使用,基于骨料分类,进一步简化了该模型.模型分析结果表明其不确定性服从正态分布,且与关键参数无关,采用该模型进行结构可靠度分析时可忽略其相关性.

The relationship between the prism and cube compressive strengths of recycled aggregate concrete is significantly different from that of normal aggregate concrete.However,the prediction accuracy of existing models is relatively low and the discrepancy between predicted results of these models is relatively high.139 groups of test data in literatures were collected and analyzed,and the significant influences of the replacement ratio,water absorption ratio and the compounding effect between these two parameters were disclosed.A model for the relationship between the prism and cube compressive strengths of recycled aggregate concrete was proposed,with the coefficient of variation being only 5.4%.For the convenience of usage,a simplified calculation model based on the recycled aggregate classification was also proposed.The results of the model analysis show that the model uncertainty follows a normal distribution and is independent of the key parameters.It is suggested that the correlation between the model uncertainty and the key parameters can be ignored when the model is used for reliability analysis.