自密实混凝土塑性阶段收缩补偿技术试验研究  

Experimental Study on Shrinkage Compensation Technology of Self-compacting Concrete in the Plastic Stage

作　　者：周帅 徐文 刘继虎 叶智远 ZHOU Shuai;XU Wen;LIU Ji-hu;YE Zhi-yuan(Beijing Construction Engineering New Building Materials Co.,Ltd,Beijing 100015 China;Jiangsu Subote New Materials Co.,Ltd,Nanjing Jiangsu 211103 China)

机构地区：[1]北京建工新型建材有限责任公司,北京100015 [2]江苏苏博特新材料股份有限公司,江苏南京211103

出　　处：《江苏建筑》2023年第2期144-147,151,共5页Jiangsu Construction

摘　　要：自密实混凝土塑性阶段的化学减缩和沉降收缩是导致自密实混凝土脱粘、脱空的一大主要因素。采用传统方法,在混凝土中加入铝粉,从而释放H2补偿收缩的方法,不仅发气历程短,还会产生“氢脆”现象,严重影响结构安全,因此铝粉的使用受到严格限制。基于此原因,文章发明了一种偶氮二甲酰胺发气材料,并从等待时间、环境温度和水泥净浆流动度3个因素,对其在水泥净浆塑性阶段的补偿收缩效果进行表征。成功应用于自密实混凝土塑性阶段的收缩补偿,对混凝土的力学性能和耐久性能无不利影响;成功制备出一种性能优良的自密实混凝土塑性收缩补偿功能材料。The chemical shrinkage and settlement shrinkage of self-compacting concrete in the plastic stage are the main factors that lead to the debonding and separation of self-compacting concrete.In the traditional method,aluminum powder is added to concrete to release H2 to compensate the early shrinkage of concrete.But this method,not only the gas release time is short,but also will lead to "Hydrogen embrittlement" phenomenon,serious impact on structural safety,so the use of aluminum powder has been strictly limited.For this reason,a kind of azodicarbonamide foaming agent was invented,and its compensating shrinkage effect in the plastic stage of cement paste was characterized by three factors:waiting time,environmental temperature and fluidity of cement paste.And it has been successfully applied to the shrinkage compensation of self-compacting concrete in the plastic stage,which has no adverse effect on the mechanical properties and durability of concrete.Finally,a kind of self-compacting concrete with excellent performance for plastic shrinkage compensation was successfully prepared.

关 键 词：塑性阶段 收缩变形 膨胀剂 含气量 自密实混凝土 

分 类 号：TU528[建筑科学—建筑技术科学]