MgO膨胀剂在大体积混凝土结构中的抗裂效果研究  

Study on the Anti-cracking Efficiency of MgO Expansive Agent on Shrinkage-compensating Concrete in Mass Concrete Wall Structure

作　　者：曹丰泽[1] 高玉亭 张慧杰 阎培渝[1] CAO Feng-ze;GAO Yu-ting;ZHANG Hui-jie;YAN Pei-yu(Department of Civil Engineering,Tsinghua University,Beijing 100084,China;Shenzhen Construction Engineering Group Co.,Ltd.,Shenzhen 518051,China)

机构地区：[1]清华大学土木工程系,北京100084 [2]深圳市建工集团股份有限公司,广东深圳518051

出　　处：《混凝土与水泥制品》2021年第8期24-27,共4页China Concrete and Cement Products

基　　金：国家自然科学基金项目(51878381、51678344)。

摘　　要：研究了掺加MgO膨胀剂配制的补偿收缩混凝土在具有高抗裂性要求的大体积混凝土侧墙施工过程中的体积变形和温度变化情况。现场试验结果表明:掺加6.2%M型MgO膨胀剂的C35补偿收缩混凝土在满足强度发展要求的前提下,可以在大体积混凝土结构内部温度下降段产生一定的膨胀,并长期保持稳定,补偿混凝土结构的温度收缩,从而使结构内部产生少量的预压应力,降低混凝土结构收缩裂缝的出现几率。The temperature and volume variation of shrinkage-compensating concrete mixed with MgO expansive agent was measured during the construction of a mass concrete wall with high anti-cracking requirement.The results show that MgO expansive agent compensates the shrinkage of mass concrete effectively during the descending period of temperature.The ultimate volumetric expansive rate of concrete is positive,forming a compressive pre-stress to resist cracking of concrete effectively.

关 键 词：氧化镁膨胀剂 补偿收缩混凝土 大体积结构 抗裂 膨胀率 

分 类 号：TU528.042.4[建筑科学—建筑技术科学]