摘要
侧墙混凝土结构快速温降过程中很大的温度收缩是导致其易于开裂的关键原因。为抑制这一风险,从温度场与膨胀历程双重调控角度出发,一方面通过新型水化热调控材料削弱侧墙混凝土温峰,控制温降速率,抑制温度收缩;另一方面掺入CaO类高效膨胀剂,产生显著有效膨胀,补偿侧墙混凝土结构温度收缩和自收缩。二者复合使用,是提升侧墙混凝土抗裂性行之有效的方法。这一技术在重庆天和国际商业中心侧墙大体积混凝土结构中得到成功应用,混凝土14 d水养限制膨胀率达0.028%,并降低了结构中心部位最高温升约6.2℃,降温幅度近10%。
It is the key reason for sidewall concrete cracking that high temperature shrinkage occurred in rapid temperature decline process of the structure. In this paper,the dual-regulation technology of temperature field and expansion history was used to restrain the cracking risk. On one side,a new type of chemical admixture was developed to weaken the temperature peak of sidewall concrete,control its temperature drop rate and reduce the temperature shrinkage;on the other side,CaO expansion agent was employed to produce remarkable and effective expansion to compensate the temperature shrinkage and autogenous shrinkage. The compound use of the above two materials is a proven method to improve crack resistance of sidewall concrete. This dual-reg-ulation technology of temperature field and expansion history has been successfully applied in the sidewall structure of Chongqing Tianhe International Business Center project. The 14 d concrete limited expansion rate reached 0.028%,mean while the maximum temperature rise in the central site of the structure was decreased by about 6.2 ℃ and the decrease extent was close to 10%.
出处
《新型建筑材料》
2014年第1期39-41,45,共4页
New Building Materials
关键词
开裂
温度场
膨胀历程
双重调控
大体积混凝土
cracking
temperature filed
expansion history
dual-regulation
mass concrete
