基于组合混料设计的高性能混凝土配合比优化研究

为了更加科学合理地进行高性能混凝土配合比设计,研究各个组分对高性能混凝土的影响,将水泥、矿粉、粉煤灰视为一组总质量不变的混料,细集料和粗集料视为另一组混料,通过组合设计分析了矿物掺合料、水泥、砂率的混料效应,同时得到了以坍落度和抗压强度为目标的回归方程,实现了配合比的优化设计.结果表明,为了得到工作性和抗压强度都较好的高性能混凝土,矿物掺合料的掺量和砂率均不宜过大.矿粉比粉煤灰先发挥强度作用,后期水泥与矿粉对高性能混凝土的抗压强度影响较大.砂率的增大对高性能混凝土的抗压强度影响较小,但会使高性能混凝土的坍落度先增加后降低.粉煤灰和矿粉的增加均会使高性能混凝土的坍落度增加.研究结论能够为高性能混凝土矿物掺合料、砂率的选择和配合比设计提供参考依据.

Mix Optimization of High Performance Concrete Based on Combined Mixture Design

In order to design the mix of high performance concrete more scientifically and rationally,the effect of each component in the high performance concrete was studied. Cement,ground granulated blast furnace slag(GGBS)and fly ash were regarded as a set of mix,fine aggregate and coarse aggregate were regarded as another set of mix. The mixing effect of mineral admixture,cement and sand ratio was analyzed by combined design,the regression equation of the slump and compressive strength was obtained,which can achieve the optimization of mix. The results show to get good workability and strength of high performance concrete,the content of mineral admixture and sand ratio should not be too high. The concrete early strength is greatly improved by GGBS than fly ash,in the later period,the strength of high performance concrete is effected by cement and GGBS. The increase of sand ratio has little effect on the strength of high performance concrete but has great effect on slump. The increase of fly ash and GGBS content both increase the slump of high performance concrete. The research results can provide reference for the selection of mineral admixtures,sand ratio and the mix design of high performance concrete.