再生粗骨料混凝土力学性能试验研究

Experimental investigation on mechanical properties of recycled aggregate concrete

以某10年龄期的既有建筑物废弃混凝土作为再生粗骨料原料,配制了坍落度达140 mm的C40泵送混凝土。以再生粗骨料取代率、粉煤灰取代率为主要研究参量,对配制的混凝土试块的立方体抗压、棱柱体抗压、劈裂抗拉和弹性模量等力学性能指标进行了系统的试验研究。结果表明,再生混凝土的抗压、劈裂抗拉破坏形态与普通混凝土基本一致。在满足坍落度一定的前提下,立方体抗压强度、棱柱体抗压强度和弹性模量随着再生骨料取代率的增加而降低,而随着粉煤灰取代率的增加而有所提升;劈裂抗拉强度离散性较大,无明显规律;各力学指标间关系受再生粗骨料和粉煤灰取代率的影响也不明显。研究结果可为再生粗骨料的应用提供参考。

Using recycled coarse aggregate of an old buildings with about 10 years old as raw materials,the recycled aggregate concrete(RAC)with compressive strength of C40 and the slump about 140 mm was successfully prepared.The main variables were the replacement rate of recycled coarse aggregate and fly ash.The compressive strength,splitting strength and modulus of elasticity of recycled coarse aggregate concrete and natural coarse aggregate concrete(NAC)were studied.It was found that the failure modes were almost the same for RAC and NAC;and for a certain slump,the compressive strength and the modulus of elasticity of RAC decreased with the increase of replacement ratio of recycled coarse aggregate,while increased with the increase of fly ash replacement.And the splitting strength was not obviously influenced by both variables,so were also the relationships between mechanical performance indexes.All the above can be as reference.