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通过变化再生细骨料的预吸水程度及掺量研究预吸水再生细骨料对混凝土干缩及抗冻性能的影响,研究结果表明:掺加再生细骨料会造成混凝土的干缩值增大,但不同于普通混凝土,再生细骨料混凝土28d~120d完成了全部干缩值的70%~85%;当再生细骨料替代率和初始含水率分别为50%时,后期其收缩性能与普通混凝土最为接近;掺加再生细骨料会导致混凝土抗冻性能下降,再生细骨料初始含水率为50%的混凝土抗冻性能下降较小且随龄期的增长抗冻性能提高幅度较大;适度预吸水的再生细骨料可以发挥类似于“内养护”的作用,从而减小再生细骨料对混凝土收缩及抗冻性能的影响。
The effect of pre-absorbent fine aggregate on the shrinkage and frost resistance of concrete was studied by varying the pre-absorbent degree and content of regenerated fine aggregate. The results show that the incorporation of regenerated fine aggregate will increase the shrinkage value of concrete , But different from the ordinary concrete, the recycled fine aggregate concrete completed 70% ~ 85% of the total dry shrinkage value from 28d to 120d. When the recycled fine aggregate replacement rate and the initial water content were 50% Ordinary concrete is the closest; Addition of regenerated fine aggregate will lead to the decrease of frost resistance of concrete; the frost resistance of concrete with the initial water content of 50% of regenerated fine aggregate decreases less and the antifreeze performance increases more with the increase of age ; Moderate pre-absorbent regenerated fine aggregate can play a role similar to the “conservation”, thereby reducing the impact of recycled fine aggregate concrete shrinkage and frost resistance.