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某医院直线加速器区大体积混凝土裂缝控制关键技术
作者：王德民1，卫剑楠2，马锋2，郑志华2，辜振睿1，李润1
（1.武汉三源特种建材有限责任公司，湖北 武汉 430083；2.南通八建集团有限公司，江苏 南通 226002）
摘要：通过配合比设计优化调整、配套的浇筑施工和养护工艺，使混凝土材料自身与施工技术得到了有效结合，实现了医院直线加速器区大体积混凝土结构无有害裂缝的目标。在大幅延长木模板带模时间（≥20 d）的基础上增加覆盖棉被或土工布层数的做法，是侧墙等竖向大体积混凝土结构裂缝控制的重点，能有效控制其内部的降温速率（≤4 ℃/d）和里表温差（≤25 ℃）。实体结构内部温度修正后应变最大值高达132 με，30 d后最小值仅为-80 με，说明在混凝土温降阶段氧化镁膨胀剂补偿了部分收缩，大幅提高了大体积混凝土的抗裂性能。
关键词：直线加速器；大体积混凝土；裂缝控制；氧化镁膨胀剂；降温速率
中图分类号：TU528.04 文献标识码：A 文章编号：1001-702X（2022）10-0051-04
Key technology for crack control of mass concrete in linear accelerator area of a hospital
WANG Demin1，WEI Jiannan2，MA Feng2，ZHENG Zhihua2，GU Zhenrui1，LI Run1
（1.Wuhan Sanyuan Special Building Materials Co. Ltd.，Wuhan 430083，China；
2.Nantong Eighth Construction Group Co. Ltd.，Nantong 226002，China）
Abstract：Through proportion optimization design adjustment，matching pouring construction and maintenance technology，concrete material and construction technology was effectively combined. The goal of no harmful cracks in mass concrete structure of the linear accelerator area was achieved. The number of cotton cover or geotextile layers was increased on the basis of a substantial increase in the holding time of wood formwork（≥20 days）. This approach was the focus of crack control for vertical mass concrete structures such as side walls，and it could effectively control the internal detemperature rate（≤4 ℃/d） and the internal surface temperature difference（≤25 ℃）.The maximum microstrain of the solid structure after temperature correction was as high as 132 με，and the minimum value was only -80 με after 30 days. It indicated that MgO expansive agent compensated part of the shrinkage during the temperature drop stage of concrete，greatly improved the crack resistance of mass concrete.
Key words：linear accelerator，mass concrete，crack control，MgO expansion agent，detemperature rate