摘要
赤壁长江公路大桥主桥设计为双塔双索面结合梁斜拉桥,为优化桥塔混凝土配合比,掌握桥塔混凝土性能特点,研究了粉煤灰单掺、粉煤灰和矿粉复掺对桥塔C50混凝土性能的影响,并通过压汞仪(MIP)和扫描电镜(SEM)分析了矿物掺合料对桥塔混凝土亚微观结构的影响。结果表明,采用粉煤灰和矿粉复合掺合料配制的桥塔C50混凝土工作性和强度符合设计和施工要求,干缩值较低,且早期强度及强度增进率、弹性模量、抗氯离子渗透性和抗碳化性能均优于单掺粉煤灰混凝土。复掺粉煤灰和矿粉对混凝土孔结构的细化作用和微结构的改善作用优于单掺粉煤灰。
The main bridge of the Chibi Yangtze River Highway Bridge is designed as a cable-stayed bridge with double tower and double cable plane.In order to optimize the mix proportions of the bridge tower concrete and understand the performance characteristics of the bridge tower concrete,the effects of single addition of fly ash(FA),and the compound of FA and ground blast furnace slag(GBFS)on the performance of the bridge tower C50 grade concrete were investigated,and the influence of mineral admixtures on the microstructure of the bridge tower concrete was analyzed by mercury porosimeter(MIP)and scanning electron microscope(SEM).The results show that the workability and strength of the bridge tower C50 concrete prepared with FA and GBFS composite admixtures meet the design and construction requirements,and its drying shrinkage value is low.Meanwhile,the bridge tower concrete prepared with FA and GBFS composite admixtures are better than the concrete with single addition of FA in early strength and strength development,elastic modulus,resistance to chloride ion permeability and anticarbonation of C50 concrete.Compared with single addition of FA,the composite additions of FA and GBFS had a better action on the refinement of pore structure and the improvement of microstructure of concrete.
作者
徐小华
谢俊凡
夏伟航
李北星
XU Xiao-hua;XIE Jun-fan;XIA Wei-hang;LI Bei-xing(Hubei Province Chibi Yangtze River Highway Bridge Co.,Ltd.,Chibi,Hubei 437300,China;State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan,Hubei 430070,China)
出处
《中国港湾建设》
2021年第2期40-45,共6页
China Harbour Engineering
基金
国家自然科学基金项目(51372185)。
关键词
桥塔
矿物掺合料
混凝土
配合比设计
性能
微结构
bridge tower
mineral admixture
concrete
mix proportion design
performance
microstructure
