【摘要】 利用热膨胀仪测得硬化水泥浆和粗集料热变形性能存在较大的差异,在一定条件下二者的即时线膨胀系数相差2倍左右;经过热循环(室温—75℃)作用,粗集料与水泥浆的界面可产生微裂纹,进一步的热循环将促进裂纹扩展;120次热循环后水泥基材料的抗压强度下降超过30%。试验结果表明组分热变形差异的存在,对处于热疲劳作用下水泥基材料的热稳定性和力学性能将产生显著影响。更多还原

【Abstract】 The thermal deformation behavior of hardened cement paste and coarse aggregate were conducted by the WorkHorse-1 Dilatometer made in Anter Corporation(USA).The results showed that thermal expansion coefficient of hardened cement paste was over two times than that of coarse aggregate with great diversity.After more thermal cycles,the microcracking induced by the thermal stress appeared and propagated along the interfacial zone between hardened cement paste and aggregate.When to experience 120 thermal cycles,the reduction percentage of compressive strength for cement-based was over 30%,which aggravated the structure damage under load.All of above results approved that the existence of thermal deformation difference between components influence the thermal stability and mechanical performance under the thermal fatigue.更多还原