摘要
采用温控型钙镁复合膨胀剂配制了补偿收缩混凝土,重点分析和研究了抗裂防渗混凝土在实体结构大体积混凝土中的温峰控制和微应变变化规律。研究结果表明:采用温控型钙镁复合膨胀剂配制的抗裂防渗混凝土在明挖穿湖隧道工程主体结构大体积混凝土中具有良好的温控抗裂防渗效果。与基准混凝土相比,抗裂防渗混凝土水中14 d限制膨胀率提高了0.025%、水中14 d转空气中28 d限制膨胀率提高了0.035%。实体结构监测数据表明,相比于普通防水混凝土,抗裂防渗混凝土基础底板中心温度峰值降低了7.2℃,峰值的出现时间延长了约8 h,30 d龄期内温度修正后微应变的最大值和最小值分别增加了59×10^(-6)和95×10^(-6),综合微应变最大值和最小值分别增加了33×10^(-6)和106×10^(-6);外墙中心温度峰值降低了5.8℃,峰值的出现时间延长了约10 h,30 d龄期内温度修正后微应变的最大值和最小值分别增加了53×10^(-6)和95×10^(-6),综合微应变最大值和最小值分别增加了42×10^(-6)和87×10^(-6)。
A temperature controlled calcium magnesium composite expansion agent was used to prepare compensating shrinkage concrete.The temperature peak control and micro strain variation law of crack resistant and anti-seepage concrete in mass concrete were analyzed and studied in detail.The research results indicate that the crack resistant and anti-seepage concrete formulated with temperature controlled calcium magnesium composite expansion agent has good temperature control,crack resistance and anti-seepage effects in the project.Compared with the benchmark concrete,the crack resistant and anti-seepage concrete has a 0.025%increase of the 14 day restricted expansion rate in water and a 0.035%increase of the 28 day restricted expansion rate in air after 14 days in water.The monitoring data shows that compared with ordinary waterproof concrete,the peak temperature of the center of the crack resistant and anti-seepage concrete foundation bottom plate decreased by 7.2℃,and the appearance time of the peak extended by about 8 hours.Both the maximum and minimum values of the micro strain after temperature correction increased by 59×10^(-6) and 95×10^(-6),respectively during the 30 day age period.The maximum and minimum values of the comprehensive micro strain increased by 33×10^(-6) and 106×10^(-6),respectively;The peak temperature at the center of the exterior wall decreased by 5.8℃,and the appearance time of the peak was extended by about 10 hours.During the 30 day age,the maximum and minimum values of the micro strain after temperature correction increased by 53×10^(-6) and 95×10^(-6),respectively.The maximum and minimum values of the comprehensive micro strain increased by 42×10^(-6) and 87×10^(-6),respectively.
作者
范从友
王德民
Fan Congyou;Wang Demin(Zhongyifeng Construction Group Co.,Ltd.,Suzhou 215131,China)
出处
《市政技术》
2025年第3期261-267,共7页
Journal of Municipal Technology
关键词
明挖穿湖隧道
大体积混凝土
补偿收缩混凝土
温控型钙镁复合膨胀剂
温控抗裂防渗性能
温峰控制
微应变
open-cut lake-crossing tunnel
mass concrete
shrinkage compensating concrete
temperature-controlled calcium-magnesium composite expansion agent
temperature-controlled crack resistant and anti-seepage property
temperature peak control
micro-strain
