考虑应变软化的再生混凝土应力-应变全曲线方程

由于影响因素较多,确定再生混凝土的应力-应变全曲线性能需要积累较多的研究结果。采用0、50%和100%3种取代率,70 mm×70 mm×148 mm棱柱体试件,电-液伺服试验机,等位移速率加载,进行了再生混凝土单轴受压试验,获得了再生混凝土全曲线。试验表明:随取代率的增加,再生混凝土弹性模量略有减少,峰值应变逐渐增加,曲线上升段的略有差异。50%取代率组强度极限时试件的裂缝发展稳定性较差,100%取代率组峰值应力低变形能力较好。根据试验结果分析了应变软化现象,建立了再生混凝土考虑软化现象的全曲线方程。

Complete stress-strain curve equation of recycled aggregate concrete considering strain soften property

The recycled concrete has more factors that affect the factors of complete stress-strain curve,the more result of the test curves are needed to accumulate to confirm the property of recycled concrete.In this paper,three replacement rate of recycled aggregate were 0,50%and 100%,the dimension of the specimens were 70 mm×70 mm×148 mm,electric-hydraulic servo testing machine and displacement rate control loading were used in uniaxial compression test.Tests predicted that with the replacement rate increased,the recycled concrete elastic modulus decreased slightly,and the peak strain increased.The ascending part of the curve had a slightly different among these three groups.At the ultimate strength the cracks of 50% replacement rate had more unstable comparing the virgin aggregate samples,the 100% recycled concrete samples had lower ultimate stress and higher deformation.According to result of test,the strain softening phenomenon of recycled was discussed,the equation of recycled concrete complete stress-strain curve was established considering strain softening.