固废粗集料平均弹性模量与混凝土弹性模量的相关性

Correlation Between Average Elastic Modulus of Solid Waste Coarse Aggregate and Elastic Modulus of Concrete

试验研究了12种不同固废粗集料压碎值试验中σ-ε曲线与配制混凝土的静态弹性模量之间关系,进行了压碎值试验固废粗集料变形的离散元数值模拟,分析了国内外主要标准中公式计算固废粗集料混凝土弹性模量误差偏大的原因。研究结果表明:基于中国、美国和欧洲标准的普通密度固废粗集料混凝土弹性模量计算值分别高出实测值45.5%、15.8%和52.5%;固废粗集料在压碎值试验σ-ε曲线的线性区间主要发生弹性变形;建立的固废粗集料σ-ε曲线指数模型拟合度高,R^(2)均大于0.99;通过在传统的压碎值试验中引入粗集料平均弹性模量、含水系数等参数,回归建立了固废粗集料混凝土弹性模量半经验公式,R^(2)为0.867。利用已有文献数据对半经验公式的普适性进行了检验,高判定系数(R^(2)=0.895)实测值与预测值的比较表明模型具有有效性,为快速、可靠预测固废粗集料混凝土弹性模量提供了依据。

The correlation between theσ-εcurve characteristics of twelve solid waste coarse aggregate in the crushing value test and the static elastic modulus of concrete was studied experimentally,and the deformation of coarse aggregate in crushing value test was simulated by discrete element method,as well as the reason of big error in calculating elastic modulus of solid waste coarse aggregate concrete by expressions in main codes at home and abroad was analyzed.The results showed that the calculated values of elastic modulus of ordinary density solid waste coarse aggregate concrete by the codes from Chinese,American and European are 45.5%,15.8%and 52.5%higher than the measured values,respectively;the solid waste coarse aggregate maintains almost elastic state within the linear region ofσ-εcurve;the established solid waste coarse aggregateσ-εcurve exponential model has a high degree of fit,R^(2)>0.99;by introducing the parameters such as average elastic modulus and water content coefficient of coarse aggregate based on the traditional crushing value test,the semi-empirical expression of elastic modulus of solid waste coarse aggregate concrete was established by regression,and R^(2)is 0.867.Finally,the general applicability of the semi-empirical expression was tested by the measured values from literature,and the high judgment coefficient(R^(2)=0.895)shows the effectiveness of the expression,which provides a basis for fast and reliable prediction of elastic modulus of solid waste coarse aggregate concrete.