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内衬墙大体积混凝土温度监测及裂缝控制技术
作者：樊俊江
（上海市建筑科学研究院有限公司，上海 200032）
摘要：基于大掺量掺合料技术、掺加抗裂剂、保温保湿养护等经济便捷的措施，研究深隧工程内衬墙大体积混凝土裂缝控制技术，并通过在内衬墙环梁部位开展混凝土浇筑体温度监测和裂缝观察来验证裂缝控制效果。结果表明，当内衬墙混凝土中掺加50%粉煤灰矿粉复合掺合料，胶凝材料水化热较纯水泥降低27.5%，可有效降低混凝土浇筑体温升；掺加抗裂剂可产生膨胀应变、补偿收缩，并推迟混凝土水化进程。保温养护可降低混凝土浇筑体降温阶段的降温速率0.5~0.8 ℃/d；保湿养护可预防塑性阶段干缩龟裂缝的产生。综合4种措施可全方位降低不同类型裂缝的产生，单位面积裂缝数量降低80%以上，部分区域基本实现无裂缝。
关键词：深隧工程；大体积混凝土；掺合料；抗裂剂；裂缝控制
中图分类号：TU528.04 文献标识码：A 文章编号：1001-702X（2022）10-0045-06
Temperature monitoring and crack control technology of mass concrete for lining wall
FAN Junjiang
（Shanghai Institute of Building Science Co. Ltd.，Shanghai 200032，China）
Abstract：Based on the economic and convenient measures such as large amount of mineral admixture，anti-cracking agent，heat preservation curing and moisturizing curing，the crack control technology of mass concrete of inner lining wall in deep tunnel engineering is studied，and the crack control effect is verified by carrying out temperature monitoring and crack observation of concrete pouring body at the ring beam of inner lining wall. The results show that when 50% fly ash and slag composite admixture is added to the lining wall concrete，the hydration heat of cementitious material is reduced by 27.5% compared with that of pure cement，which can effectively reduce the temperature rise of concrete pouring; Adding anti cracking agent can compensate shrinkage，produce expansion strain and delay the hydration process of concrete. Heat preservation curing can reduce the cooling rate of concrete pouring body at the cooling stage by 0.5~0.8 ℃/d. Moisturizing curing can prevent the occurrence of dry shrinkage cracks in plastic stage. Combining the four measures can comprehensively reduce the generation of different types of cracks，reduce the number of cracks per unit area by more than 80%，and basically achieve no cracks in some areas.
Key words：deep tunnel engineering，mass concrete，mineral admixture，anti-cracking agent，crack control