【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S_F在600~700 mm之间,流动性较好;拌合物完全出筒时间T_F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。S_F>700 mm或4 s≤T_F≤7 s,要注意观察拌合物离析倾向。T_F>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。更多还原

【Abstract】 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 SFof modified slump cone between 600 mm to 700 mm indicates that the fluidity of fresh concrete is good. If the time of freshconcrete TFgoing out of the modified slump cone completely is between 4 s and 21 s and the ellipticity δ 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 than1 and the ellipticity δ is less than 2. 4%,it can be considered that the anti-separation quality of fresh concrete is good. When the value of SFis larger than 700 mm or the value of TFis between 4 s and 7 s,it is important to observe the trend of segregationin fresh concrete mixture. That the value of TFis larger than21 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 qualitythrough gaps of fresh concrete.更多还原