氧化镁膨胀剂在超长墙体结构裂缝控制中的应用研究  

Application research of MgO expansive agent in crack control of super-long wall structure

作　　者：刘汉宏 王德民 舒震林 王海林 吴爱 李治祥 张港 LIU Hanhong;WANG Demin;SHU Zhenlin;WANG Hailin;WU Ai;LI Zhixiang;ZHANG Gang(Hunan Provincial Transportation Planning Survey and Design Institute Co.Ltd.,Changsha 410200,China;Wuhan Sanyuan Special Building Materials Co.Ltd.,Wuhan 430083,China;Taizhou Same Construction Engineering Quality Inspection Co.Ltd.,Taizhou 225300,China)

机构地区：[1]湖南省交通规划勘察设计院有限公司,湖南长沙410200 [2]武汉三源特种建材有限责任公司,湖北武汉430083 [3]泰州市同一建设工程质量检测有限公司,江苏泰州225300

出　　处：《新型建筑材料》2024年第3期57-60,69,共5页New Building Materials

摘　　要：氧化镁膨胀剂的微膨胀性能可较好地补偿混凝土早期温降收缩,在超长墙体结构中具有良好的裂缝控制效果。实体结构监测数据表明,300~400 mm厚墙体结构在木模板带模养护条件下,内部温度在15~24 h到达温峰值,到达温峰值后前3 d的降温速率在5.0~9.3℃/d,在2~5 d内产生早期温降收缩裂缝;超长墙体结构的连续直墙长度越长,裂缝数量越多;在工程实体结构相比普通混凝土,采用氧化镁膨胀剂配制的补偿收缩混凝土30 d内的温度修正后微应变增长了80με~134με,综合微应变值增长了100με~185με。The micro-expansion performance of MgO expansive agent in concrete can better compensate the early temperature drop shrinkage,and has a good crack control effect in the ultra-long wall structure.The monitoring data of the solid structure show that the internal temperature of the 300~400 mm thick wall structure reached the temperature peak at about 15~24 h under the curing condition of the wood formwork,and the cooling rate of the first three day after reaching the temperature peak was about 5.0~9.3℃/d.Early temperature drop shrinkage cracks would basically occur within 2~5 d,and the longer the length of the continuous straight wall of the super-long wall structure,the more the number of cracks.Compared with ordinary concrete,the micro-strain of shrinkage-compensating concrete prepared with magnesium oxide expansive agent increased by 80με~134μεafter temperature correction within 30 days in the engineering solid structure,and the comprehensive micro-strain value increased by 100με~185με.

关 键 词：氧化镁膨胀剂 补偿收缩混凝土 超长墙体结构 裂缝控制 微应变 

分 类 号：TU755[建筑科学—建筑技术科学]