中文摘要：

针对以往没有考虑冷却方式对再生混凝土高温后强度的影响，以及再生混凝土高温后强度改变机理不够明确的现状，进行了再生混凝土高温后经历自然冷却（自冷）和水冷却（水冷）后的抗压强度试验，基于试验结果，建立了再生混凝土高温后自冷和水冷后的强度计算公式，并从微观结构探讨其强度变化机理。试验表明，在600℃以前，再生混凝土高温后水冷比自冷的强度低很多，但600℃后两者强度接近。随着温度的升高，再生粗骨料与水泥石的界面裂缝加宽，同时水泥石孔洞尺寸变大，结构变得疏松，并且水冷却比自然冷却对微观结构损伤更大。

英文摘要：

Considering that influence of cooling mode on strength of recycled concrete （RC） experienced high temperature was not considered,and change mechanism of RC strength experienced high temperature had not been known fully,Compression test of RC experienced high temperature was done, and based on the result, formula of compress strength for RC by water cooling and by air cooling is build,and its change mechanism was explored from microstructure.The test results show that before 600 ℃ ,RC strength experienced high temperature is very smaller by water cooling than by air cooling,but after 600 ℃ ,both is close to each other.With temperature increasing, interface crack between recycle coarse and cement paste becomes wider, and cement paste＇s pore structure becomes looser, and pore size becomes bigger, and microstructure damage is more serious by water cooling than by air cooling.