中文摘要：

基于70%再生粗骨料取代率和净浆裹石法拌制再生混凝土,研究不同再生细骨料取代率及矿物掺合料品种与掺量对再生混凝土干燥收缩性能的影响规律。试验结果表明：再生混凝土的干缩应变比同条件下普通混凝土大40%左右,随着矿物掺合料掺量的增加,再生混凝土的干缩应变先减小后增大,单掺粉煤灰效果比复掺粉煤灰与矿渣效果更好,其最优掺量为40%,此时可使再生混凝土干缩应变低于普通混凝土。随着再生细骨料掺量的增加,再生混凝土的干缩应变增大,在单掺粉煤灰40%情况下,再生细骨料取代率在70%以内时,其干燥收缩可低于普通混凝土。在分析试验结果基础上,拟合出适用于再生混凝土干燥收缩的计算模型。

英文摘要：

The aggregates enveloped with cement method was used to produce the recycled concrete with 70% recycled coarse aggregate replacement rate.The factors that affect the drying shrinkage of recycled concrete were studied,including recycled fine aggregate replacement rates and different kinds and content of mineral admixture.The results show that the drying shrinkage strain of recycled concrete is about 40% greater than that of normal concrete in the same condition.With the increase of content of mineral admixture,the drying shrinkage strain of re- cycled concrete decreases at first and then increases.Compared with equivalent replacement of cement with fly and slag admixture, the ce- ment single mixed with fly ash is more effective to reduce the drying shrinkage strain of recycled concrete.The optimal content of fly ash is 40%.The drying shrinkage strain of recycled concrete with 40% content of fly ash can be no more than that of normal concrete.The drying shrinkage strain of recycled concrete increases with the increase of recycled fine aggregate replacement rates.Based on the optimal content of fly ash,the drying shrinkage strain of recycled concrete with no more than 70% recycled fine aggregate replacement rate can be lower than that of normal concrete.Based on the test results, the formula to predict the drying shrinkage strain of recycled concrete is proposed.