高强再生混凝土干缩特性

研究了再生粗细骨料对混凝土干缩性能的影响，试验结果表明，再生骨料对混凝土的干缩影响显著，尤其是再生细骨料。重点研究了高强再生粗骨料混凝土的干缩特性，通过高强再生混凝土配合比优化设计，再生粗骨料混凝土的干缩率仅稍大于天然粗骨料混凝土，与其基本相当。在再生混凝土中掺膨胀剂具有很好的补偿收缩效果，达到高强再生混凝土微千缩的目的。研究表明，干燥环境养护对再生混凝土强度的影响明显大于普通混凝土，因此，再生混凝土更需注意保湿养护。还从界面结构和骨料特性分析了再生混凝土的干缩机理。

Dry Shrinkage Features of High strength Recycled Concrete

At first, the influence of recycled coarse and fine aggregate on dry shrinkage features of concrete was studied. It is indicated that the recycled aggregate makes significant impact on dry shrinkage features of concrete, particularly the fine aggregate. Through the optimization of the mix of recycled high-strength concrete, the dry shrinkage rate of coarse aggregate concrete was only slightly larger than that of the natural one. Bulking agent used in recycled concrete could compensate the shrinkage effectively to achieve the objective of micro-shrinkage. At the same time, it is shown that the impact of conservation in dry environment on recycled concrete strength is greater than that of ordinary one. Thus, more attention should be paid to the moisture in the conservation of recycled concrete. In addition, the shrinkage mechanism of recycled concrete was analyzed from the perspectives of interface structure and aggregate features.