基于两相复合材料的再生混凝土弹性模量预测模型

Compared with models that employ compressive strength of recycled aggregate concrete (RAC) to predict its elastic modulus, models based on two-phase composite material can better reflect the influences of recycled coarse aggregate (RCA) on the elastic modulus of RAC, and thus can provide better predictions. Current model is deduced by taking the weighted average of elastic modulus of aggregate and mortar phases as the elastic modulus of RAC, which is usually conservative. Different composite models have provided various predictions for elastic modulus of natural aggregate concrete. This paper considered the influences of residual mortar and deduced six models for elastic modulus of RAC based on the composite models. Based on 100 test data, the proposed models were assessed, and model uncertainties and their correlation with RAC parameters were evaluated, which provide statistical information for further reliability analysis of RAC members and structures. It is shown that the differences between model prediction results can reach up to 23.3%. BNC(RAC) model has the most accuracy, and the mean value and coefficient of variation of the ratio between its predictions and test data are 1.014 and 8.2%, respectively. The model uncertainty is normally distributed.