内养护对混凝土抗裂性及水化的影响  

Influence of Internal Curing on Crack Resistance and Hydration of Concrete

作　　者：朱长华[1,2] 李享涛[1,2] 王保江[1,2] 谢永江[1,2] 

机构地区：[1]中国铁道科学研究院铁道建筑研究所,北京100081 [2]中国铁道科学研究院高速铁路轨道技术国家重点实验室,北京100081

出　　处：《建筑材料学报》2013年第2期221-225,共5页Journal of Building Materials

基　　金：铁道部科技研究开发计划项目(2010G019-A)

摘　　要：用3种高吸水聚合物(super-absorbent polymer,SAP)作为内养护剂,通过研究其在饱和Ca(OH)2溶液中的吸水特性及配制混凝土的工作性进行优选.研究了优选SAP掺量及粒径对混凝土早期变形和抗裂性的影响,并通过水化热测试、X射线衍射分析内养护的作用机理.结果表明:经优选的内养护剂可减小混凝土的早期变形,提高混凝土抵抗塑性收缩、自收缩开裂的能力及水泥水化程度;内养护剂掺量对混凝土抗裂性、水泥水化程度的影响较大,而其粒径变化所带来的影响则相对较小.Using three types of SAPs as internal agent, the SAPs were compared and selected by measuring water absorption characteristic in saturated calcium hydroxide solution and the workability of fresh con crete with such SAPs. Then the effect of the optimized SAP dosage and its particle size on the early de formation and crack resistance of concrete was studied; the measurement of hydration heat and XRD were used to analyze the internal curing mechanism of the SAP. It was indicated from results that the early de formation of concrete can be reduced by using the optimized SAP, and the resistance to crack induced by initial shrinkage or autogenous shrinkage can be enhanced, besides, the hydration degree of cement can be promoted as well; as SAP dosage was increased instead of that particle size was varied, the crack resistance of concrete and hydration degree of cement increased obviously.

关 键 词：高吸水聚合物 内养护 引入水 抗裂性 水化程度 

分 类 号：TU528.01[建筑科学—建筑技术科学]