再生骨料混凝土横向变形系数及预测模型

Dilation Ratio and Modeling of Recycled Aggregate Concrete

为研究再生骨料的掺入对混凝土横向变形性能的影响,以再生骨料取代率及混凝土水灰比为主要参数,对14组共计42个150 mm×150 mm×300 mm的棱柱体试块进行轴压试验研究,量化了不同水灰比下取代率对横向变形系数的影响。基于两相复合材料理论,推导建立了可考虑不同水灰比下再生骨料影响差异的横向变形系数预测模型,并将模型预测结果与试验结果进行对比,验证了预测模型的可靠性。研究表明,再生粗、细骨料对横向变形系数耦合影响显著,且该影响随水灰比的提高而增大;所提模型预测结果与试验数据之比的平均值为1.000,变异系数为0.250。

To investigate the influence of recycled aggregate incorporation on the dilation behavior of concrete,the paper conducted the compressive tests for 14 groups of 150 mm×150 mm×300 mm prisms(totally 42 specimens)with different coarse recycled aggregate(CRA)and fine recycled aggregate(FRA)replacement ratios and water-cement ratios(w/c),and then quantified the influence of recycled aggregate(RA)replacement ratio on the dilation ratio of concrete with different w/c.Based on two-phase composite material theory,a new dilation ratio prediction model for RAC was proposed,which could consider the difference of replacement ratio influence with different w/c.The proposed model was benchmarked against the available test data.It was found that the CRA and FRA had a significant compounding effect on dilation ratio,which could be amplified by the increasing w/c ratio;the mean value and coefficient of variation(COV)for the ratio of predictions by proposed model to the available test results were 1.000 and 0.250,respectively.