活性掺合料对再生混凝土耐久性影响

由于再生集料本身具有一些天然缺陷,导致再生集料配制的混凝土综合性能较同级配普通混凝土差,而矿渣、粉煤灰等活性掺合料可以改善混凝土的物理力学性能和耐久性能.本课题采用再生粗集料以不同比例取代天然集料的同时,用矿渣、粉煤灰等活性掺合料等量取代水泥,研究掺活性掺合料再生混凝土的力学性能和耐久性能.实验结果表明,随再生集料用量增加,混凝土的物理力学性能和耐久性能有所下降,但掺加一定量的活性掺合料可以明显改善再生混凝土的耐久性能.采用合适掺量的矿渣可以配制出坍落度为180 mm,28 d强度达50 MPa以上,各种耐久性能指标均达到基准混凝土技术指标的再生集料混凝土.

Influence of active admixture to durability of recycled concrete

Because of the vice of regenerated aggregate , the all - around performence of regenerated aggregate concrete is worse than ordinary concrete in the same mix proportion. However, the active admixture such as slag, fly ash and so on could improve the physical mechanics performance and durability of concrete. In this paper, the concrete was produced by regenerated aggregate instead of natural aggregate in different ratio, and the active admixture such as slag , fly ash and so on were in equivalent replacement of cement. It studied on the physical mechanics performance and durability of recycled concrete with active admixture. Experiment results showed that physical mechanics performance and durability of concrete was decreased by the increase of regenerated aggregate, but the various ratio of active admixture could improve the durability obviously. The concrete with various ratio of slag could meet with the technique requirements of basic concrete, and the slump was 180 mm and the strength of 28 days was above 50 MPa.