减水剂的品种和掺量对预拌混凝土坍落度/扩展度经时损失的影响

伴随着预拌混凝土的普及应用,混凝土坍落度由于经失损失造成搅拌车不能正常卸料、泵送或密实成型的现象时有发生,从而影响施工效率和混凝土质量.本文通过对两个品种、2种不同掺量减水剂的对比试验,分析了减水剂的品种和掺量对预拌混凝土坍落度、扩展度以及抗压破坏荷载值经时损失的影响.试验结果表明,聚羧酸系减水剂较奈系减水剂有更好的水泥适应性,且掺量少、减水率高、混凝土坍落度及扩展度经时损失少.

Effect of Water Reducer Varieties and Amounts on the Gradual Loss in Slump and Flow of the Ready-mixed Concrete

With the popularity of ready-mixed concrete,the gradual loss in slump of the ready-mixed concrete often causes a lot of problems that the ready-mixed concrete is hard to unloading from concrete mix vehicle,pumping and dense molding,thus influences construction efficiency and concretes quality.The experiments on the effect of water reducer amounts and varieties on the gradual loss in slump and flow as well as compressive failure load values of the ready-mixed concrete are carried out.which is benefit for engineering.The test results show that,high performance water reducer can improve the initial fluidity of concrete,but it leads to the serious rheology gradual loss.Water reducer latter admixing and double-combined mineral admixtures helps to improve the slump and the flow of gradual loss.