摘要
为提高江海交汇环境下大型桥梁承台混凝土的耐久性，试验测试崇启大桥承台混凝土的基本力学性能、变形性能、氯离子扩散系数和相应胶凝材料的水化热等。研究表明，优化后的配合比混凝土基本力学性能满足设计要求；掺40％～60％矿物掺合料的混凝土28d干燥收缩率为（1．4～2．5）×10^-4，到120d趋于稳定；氯离子扩散系数随龄期的增长和掺合料的增加而降低，双掺组为单掺组的20％～30％；大掺量矿物掺合料胶凝材料的7d水化热相对未掺组降低了30％。通过优选，确定粉煤灰掺量40％、矿粉掺量20％配合比为该桥承台混凝土配合比。
To enhance the durability of the concrete for the pile caps in the confluent environment, the basic mechanical behavior, deformation behavior, chlorine diffusion coefficient and hydration heat of the corresponding binder of the concrete used in the pile caps of the Chongqi Bridge have been tested and studied. The results of the study show that the basic mechanical behavior of the concrete after its mix proportioning is optimized can meet the design requirements, the dry shrinkage ratio of the concrete added with 40%-60% of mineral admixture at 28 d is （1. 4-2.5） × 10^-4 and the shrinkage ratio tends to be stable at 120d. The chlorine diffusion coefficient decreases with the increase of concrete age and adding amount of the admixture and the coefficient of the specimen groups with double admixture is 20%-30% of the specimen groups with single admixture. In comparison to the specimen groups without admixture, the hydration heat of the binder added with great amount of mineral admixture at 7 d decreases 30%. By optimal selection, it is determined that the mix proportioning with 40% fly ash and 20% mineral admixture should be the mix proportioning of the concrete for the pile caps of the bridge.
出处
《世界桥梁》
北大核心
2011年第4期57-60,共4页
World Bridges
基金
973计划资助项目(2009CB623200)
关键词
桥梁
承台
混凝土
力学性能
变形性能
氯离子扩散系数
水化热
试验
研究
bridge
pile cap
concrete
mechanical behavior
deformation behavior
chlorine diffusion coefficient
hydration heat
test
study
