双高混凝土优化配制试验研究

Experimental Study on Mix and Preparation Optimization of Double-high-performance Concrete

混凝土高性能化是保障混凝土结构质量的基本措施。通过系列试验,优化了双高(高工作性能、高强)混凝土配合比,研究了其基本力学性能,确定了C50~C80混凝土的施工配合比。结果表明:采用P·O 42.5R普通硅酸盐水泥,掺加优质矿粉和高性能聚羧酸减水剂,可配制拌合物工作性能良好的C70、C75和C80混凝土,其基本力学性能满足现行结构设计规范要求。基于试验结果,建议了考虑胶结材料强度和密度、水胶比的双高混凝土立方体抗压强度计算公式,并分别分析了轴心抗压强度、抗压弹性模量、劈裂抗拉强度和抗折强度与立方体抗压强度的关系。

High performance of concrete is the foundation of quality of concrete structures. In this paper, by the experimental study, the mixture proportion of double-high-performance concrete with workability and high strength was optimized, and the basic mechanical properties of concrete with high workability and high strength was investigated, and the construction mixture proportion of concrete C50-C80 was determined. Results show that by using ordinary silicate cement P ·O42.5R and admixing high-quality mineral powder and high-performance polycarboxylate water reducer,we made concrete C70, C75 and C80 with better workability and strength grade, and their basic mechanical properties are in accordance with current code for design of concrete structures. On the basis of test data,the for- mula considering the density and strength of eementitious materials, water binder ratio for calculating compressive strength of double- high-performance concrete is suggested, and the relations of axial compressive strength, splitting tensile strength, flexural strength and modulus of elasticity to cubic compressive strength are analyzed.