再生粗骨料特性及其对再生混凝土性能的影响

Properties of Recycled Coarse Aggregate and Its Influence on Recycled Concrete

关键词:  再生混凝土  粗骨料  普通混凝土  坍落度  土性  水灰比  压碎指标  吸水特性  降低  性能

Key words:  recycled coarse aggregate(RCA),recycled concrete,water absorption,slump,compressive strength

摘要:

系统测试了再生粗骨料的基本特性，研究了不考虑与考虑再生粗骨料的高吸水特性时再生混凝土的基本性能．结果表明，再生粗骨料的基本性能与天然骨料相比存在一定差异，主要表现为密度低、吸水率大、压碎指标大、坚固性差．不考虑再生粗骨料的吸水特性时，再生混凝土的坍落度偏小，强度低于普通混凝土，且水灰比越大，强度降低越多；考虑再生粗骨料的吸水特性时，再生混凝土可获得与普通混凝土相近的坍落度，强度则较普通混凝土降低更多，但其降低程度随水灰比的增大而减小。

Abstract:

Some properties of recycled coarse aggregate (RCA) were tested. The basic performance of recycled concrete with or without considering the high water absorption of RCA was studies. The results indicate that properties of RCA are different from that of natural coarse aggtegate (NCA), mainly characterized as low density, high water absorption and crush index as well as low soundness. The slump and compressive strength of concrete with recycled aggregate are lower than that of concrete with natural aggregate when high water absorption of RCA is not considered. However, when high water absorption is considered, the compressive strength decreases further, while the slump can be similar to that of concrete with natural aggregate.