补偿收缩混凝土在某箱体式污水处理厂中的应用  

Application of Shrinkage-compensating Concrete in a Box-type Sewage Treatment Plant

作　　者：舒震林 王德民 刘大为 武鹏飞 聂涛涛 郭海龙 张港 

机构地区：[1]武汉三源特种建材有限责任公司,湖北武汉430083 [2]中铁上海工程局集团有限公司,上海200436 [3]江苏诚意集团有限公司,江苏徐州221000

出　　处：《混凝土世界》2024年第5期80-84,共5页China Concrete

摘　　要：为提高箱体式污水处理厂主体结构混凝土的抗裂防渗性能,实现箱体式污水处理厂超长超大钢筋混凝土结构的无缝施工,本文采用“氧化镁膨胀剂配制的补偿收缩混凝土+膨胀加强带”组合技术,并在徐州市某箱体式污水处理厂工程箱体中应用。结果表明:在木模板带模养护条件下,外墙大体积混凝土内部到达温峰值后前3 d的平均降温速率超过了5 ℃/24 h,降温速率较快,若拆模过早则会进一步增大降温速率,温降收缩过大会导致竖向墙体结构早期产生有害裂缝;基础筏板和外墙混凝土内部温度修正后微应变最大值范围分别为84~107 με和37~65 με,30 d内缓慢降至8~34 με和-53~-88 με,氧化镁类补偿收缩混凝土能较好补偿早期温降收缩,筏板混凝土在30 d龄期内一直处于微膨胀状态,外墙混凝土收缩量相对较小,各实体结构均具有良好的抗裂防渗性能。In order to improve the crack resistance and anti-seepage performance of the main structure concrete of the box type sewage treatment plant,and achieve seamless construction of the ultra long and super large reinforced concrete structure of the box type sewage treatment plant,this paper adopts the combination technology of"compensating shrinkage concrete prepared with magnesium oxide expansion agent+expansion reinforcement belt",and applies it in the box body of a box type sewage treatment plant project in Xuzhou.The results show that under the condition of wooden formwork with mold curing,the average cooling rate of the large volume concrete inside the exterior wall in the first 3 days after reaching the temperature peak exceeds 5℃/24 h,with a fast cooling rate.If the mold is removed too early,the cooling rate will further increase.Excessive temperature shrinkage will lead to harmful cracks in the vertical wall structure in the early stage;the maximum microstrain values of the internal temperature correction for the foundation raft and exterior wall concrete are 84~107μεand 37~65με,respectively,and slowly decreased to 8~34μεand﹣53~﹣88μεwithin 30 days,magnesium oxide compensating shrinkage concrete can effectively compensate for early temperature drop shrinkage.Raft concrete has been in a slightly expanded state for 30 days,and the shrinkage of exterior wall concrete is relatively small.All solid structures have good crack resistance and anti-seepage performance.

关 键 词：箱体式污水处理厂 补偿收缩混凝土 氧化镁膨胀剂 抗裂防渗 微应变 

分 类 号：TU755[建筑科学—建筑技术科学] TU992.3