废弃混凝土制全再生细骨料在高强混凝土中的试验研究

Research on the recycled total-fine aggregate from waste concrete in high strength concrete

全再生细骨料是将废弃混凝土全部制备成5mm以下的再生细骨料,相比传统的再生细骨料,其具有表观密度高、吸水率低等特点。由于骨料性能明显改善,全再生细骨料有可能在高强混凝土中得到应用。本文首先根据全再生细骨料的特点进行高强混凝土配合比设计,然后与同水胶比的河砂混凝土进行对比试验,结果表明全再生细骨料能够全取代河砂应用于C70高强混凝土中,且在混凝土工作性能和抗压强度相当的情况,胶凝材料用量降低13. 0%。

Recycled total-fine aggregate is made from waste concrete by crush it all to recycled fine aggregate.Compared with the traditional recycled fine aggregate,recycled total-fine aggregate has higher apparent density and lower water absorption. Due to the obvious improvement of aggregate performance,it is possible to apply recycled total-fine aggregate in high-strength concrete. At first,by using the recycled total-fine aggregate,the high-strength concrete mixture ratio design is carried out,and then compared with river-sand concrete with same water binder ratio. The results show that the recycled total-fine aggregate can fully replace river-sand used in the C70 highstrength concrete,and at the similar workability and compressive strength,the amount of cementitious material in recycled total-fine aggregate concrete is reduced by 13. 0%.