索塔钢混结合段用大体积超高性能混凝土配制及应用研究

Research on preparation and application technology of large-volume ultra high performance concrete(UHPC) for bridge steel cable tower

针对襄阳庞公大桥索塔钢混结合段大体积超高性能混凝土(UHPC)的性能要求,采用紧密堆积理论优化UHPC胶凝材料体系各组分比例,通过掺加钢渣粉和复合膨胀剂配制出低水化热低收缩UHPC。结果表明,采用大掺量矿物掺合料优化胶材体系和集料体系,可制备出工作性能良好、各项性能指标均能满足项目要求的UHPC,绝热温升仅59.7℃,180d干燥收缩率仅280x10%钢渣粉的掺入不仅能有效降低UHPC水化热,对抑制收缩也有一定作用。

In order to meet performance requirements for large-volume UHPC in the steel-concrete joint section of the Panggong Bridge in Xiangyang. the proportion of each component of the cementitious material system is optimized by the compact packing theory,low hydration heat and low shrinkage UHPC is prepared by adding steel slag powder and composite expansion agent. The results show that UHPC with good working performance can be prepared by using high content of mineral admixture, the adiabatic temperature rise is only 59.7 ℃,the drying shrinkage rate of 180 d is only 280×10^-6, all other indicators can meet the project requirements. The hydration heat and drying shrinkage can be reduced by adding steel slag powder.