关键词: 再生骨料;碳化深度;预测模型;抗压承载力

Abstract: To systemically investigate the influence of the type of recycled aggregate and its substitution ratio on the carbonation resistance of recycled concrete, the accelerated carbonization experiment was conducted on nine kinds of recycled concrete with different replacement rates of recycled coarse aggregate and fine aggregate.Based on the experiment, the carbonation depth and variation of cubic compressive strength after 3 d, 7 d, 14 d and 28 d carbonation were analyzed.The prediction model of recycled concrete carbonation depth was established through regression analysis.The load-carrying capacity of reinforced recycled concrete prisms after 28 d carbonation was studied.The experiment results indicate that carbonation leads to an increase of the cubic compressive strength,and the extent increases with the increasing displacement ratio of recycled aggregate.Compared with ordinary concrete, the carbonation resistance of recycled concrete is decreased, and the carbonation depth of recycled concrete at different stages is slightly higher than that of ordinary concrete.The incorporation of recycled aggregate has adverse effect on the compressive capacity of concrete after carbonation.The predicted carbonation depth of recycled concrete is in good agreement with the experimental results.

Key words: recycled aggregate;carbonation depth;prediction model;load-carrying capacity