超高索塔结构抗裂混凝土性能研究

Study on performance of crack-resistant concrete with super high cable tower structure

为提升沪通长江大桥主塔高强大体积强约束混凝土结构抗裂性能,采用温度场与膨胀历程双重调控关键技术,通过绝热温升、力学试验、变形试验及耐久性能等试验,配制出低温升、高抗裂性及高耐久性能混凝土。结果表明:采用P·Ⅱ52.5水泥,掺入22.9%Ⅰ级粉煤灰+13.9%矿粉+8%抗裂功能材料、水胶比0.31、砂率43%、外加剂掺量1.3%的索塔结构C60抗裂混凝土,7 d绝热温升48.7℃、28 d自生体积变形≥50με,既具有较好的抗裂性和耐久性能,同时又能够满足高程泵送和力学性能要求。C60低温升、高抗裂混凝土在该项目上取得良好应用效果。

In order to improve the crack resistance of the high-strength and strong-constrained concrete structure of the main tower of the Hutong Yangtze River Bridge,adopting the dual control technology of temperature field and expansion process,through adiabatic temperature rise,mechanical test,deformation test and durability test methods,low-temperature-rising,high-anti-cracking and high-durability concrete was prepared.The results show that:P·Ⅱ52.5 cement is blended with 22.9%gradeⅠfly ash+13.9%mineral powder+8%anti-cracking functional material,water-gel ratio 0.31,sand ratio 43%,1.3%admixture amount of cable tower structure C60 anti-cracking concrete,the 7 d adiabatic temperature rise of 48.7℃,28 d autogenous volume deformation≥50με,not only has good anti-cracking property and durability,but also meets the requirements of high pumping and mechanical properties.C60 low temperature-rising and high-anti-cracking concrete obtained good application effect in this project.