摘   要：研究了温控型钙镁复合膨胀剂对某大型明挖穿湖隧道工程大体积混凝土抗裂防渗性能的影响。结果表明：不同结构部位混凝土内部温升为24.7~29.6 ℃，到达温峰后3 d内的降温速率为2.3~4.3 ℃/d，30 d内温度修正后应变从63~98με降低至-67~-23με；添加膨胀剂后，实体结构混凝土内部温峰降低了5.4 ℃，温峰出现时间延长了约9 h，30 d内温度修正后应变最大值和最小值分别增加了53με和76με；膨胀剂具有调控水泥水化放热历程和微膨胀补偿收缩的作用，用其制备的补偿收缩混凝土在大型明挖穿湖隧道工程大体积混凝土工程中取得了良好的抗裂防渗效果。

Abstract: The influence of temperature controlled calcium magnesium composite expansion agent on the crack resistance and anti-seepage performance of mass concrete in a large open-cut lake-crossing tunnel project was studied. The results show that the internal temperature rise of concrete in different structural parts is between 24.7~29.6 ℃, and the cooling rate within 3 d after reaching the temperature peak is 2.3~4.3 ℃/d. After temperature correction within 30 d, the strain decreases from 63~98με to -67~-23με. After adding the expansion agent, the internal temperature peak of the solid structure concrete decreases by 5.4 ℃, and the appearance time of the temperature peak is prolonged by about 9 h. Within 30 d, the maximum and minimum strain values after temperature correction increase by 53με and 76με, respectively. The expansion agent has the function of regulating the hydration heat release process of cement and compensating for micro expansion shrinkage. The prepared shrinkage-compensating concrete has achieved good crack resistance and anti-seepage effects in the mass concrete of large open-cut lake-crossing tunnel project.