改进坍落度法测试自密实混凝土工作性  

Self-compacting Concrete Workability Testing by Improved Slump Method

作　　者：李亚龙[1] 赵庆新[1] 李化建[2] 何小军[1] 安同力 赵芸平[4] 

机构地区：[1]燕山大学,秦皇岛066004 [2]中国铁道科学研究院铁道建筑研究所,北京100081 [3]丰润建筑安装工程有限公司,唐山064000 [4]唐山学院,唐山063000

出　　处：《硅酸盐通报》2016年第12期4110-4117,共8页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金项目(51578477);河北省研究生创新资助项目(2016SJSS038);燕山大学研究生创新资助项目(2015XJSS043)

摘　　要：对坍落度筒进行改进,提出了一种自密实混凝土工作性测试方法,可同时表征自密实混凝土工作性的三个方面：流动性、间隙通过性和抗离析性,并能判别引起间隙通过性不良的原因,具有方便、快捷、适合现场应用等特点。改进坍落度筒扩展度SF在600~700 mm之间,流动性较好;拌合物完全出筒时间TF在4~21 s范围内,椭圆度δ≤2.4%,间隙通过性较好;椭圆度δ≤2.4%,视觉稳定性指数VSI≤1,抗离析性较好。SF〉700 mm或4 s≤TF≤7 s,要注意观察拌合物离析倾向。TF〉21 s,混凝土流动性不足,引发间隙通过性差;δ〉2.4%,混凝土粘聚性不足,引发间隙通过性不良。A new apparatus was developed to conveniently test the workability of the self-compacting concrete （SCC）. The fluidity, passing quality through gaps and anti-separation quality of SCC can be determined simultaneously. The reason why poor passing quality through gaps occurs can also be distinguished via this method whose characteristics are convenient, fast and suitable field application. The slump flow SF of modified slump cone between 600 mm to 700 mm indicates that the fluidity of fresh concrete is good. If the time of freshconcrete Tr going out of the modified slump cone completely is between 4 s and 21 s and the ellipticity t~ is not larger than 2.4%, which means that the fresh concrete has good passing quality through gaps. If the visual stability index VSI is not larger thanl and the ellipticity 8 is less than 2.4%, it can be considered that the anti-separation quality of fresh concrete is good. When the value of SF is larger than 700 mm or the value of Tr is between 4 s and 7 s, it is important to observe the trend of segregationin fresh concrete mixture. That the value of TF is larger than 21 s implies the poor fluidity, which leads to the poor passing quality through gaps of fresh concrete. The cohesiveness is inadequate when the value of δ is larger than 2.4% , which leads to poor passing quality through gaps of fresh concrete.

关 键 词：自密实混凝土 工作性 坍落度筒 

分 类 号：TU528.01[建筑科学—建筑技术科学]