小截面预应力渡槽高性能混凝土配合比优选

Optimization of mixture ratio of high performance concrete for small section prestressed aqueduct

本文基于当前较成熟的高性能混凝土配合比设计理论,优选各类材料,对试配结果进行统计分析,以研究不同材料的配比变化对配合比的影响。试验过程中,采取适当增加胶凝材料用量,减少粗骨料用量,增大细骨料细度模数的配合比设计理念,得到具有优异的坍落度、和易性以及扩散度,特别是较低“经时坍损”的高性能混凝土及与单跨槽身浇筑进度相匹配的凝结时间。最终试配出具有高强度保证率和优异抗裂性能,且能适应小截面渡槽槽身施工的高性能混凝土配合比,体现了配合比的设计创新,为类似施工难度高的工程配合比设计提供了新的思路。

The paper is based on the current mature design theory of high performance concrete mixture ratio.Various materials are selected.The results of the test are statistically analyzed to study the influence of themixture ratiochanges of different materials on the mixture ratio.The following mixture ratio design concepts are adopted during the test,namely the dosage of cementing materials is suitably increased,the dosage of coarse aggregates is reduced,and the fineness modulus of fine aggregate is increased.Excellent slump,workability and diffusivity are obtained,especially the lower“time-lapse slump”and the setting time matched with the pouring schedule of the single-span aqueduct.Finally,the mixture ratio of high performance concrete with high strength guarantee rate and excellent crack resistanceis obtained,which is suitable for the construction of the small section aqueduct.It reflects the design innovation of the mixture ratio,thereby providing a new idea for the design of the mixture ratio in similar projects with high construction difficulty.