摘要
流动性又是表征新拌混凝土工作性能的一个重要指标,本文将常规流动性测试方法与流变测试新技术相结合,研究新拌混凝土的流变性能,提出一种简便和精确测定新拌混凝土流变特性的方法,用坍落度筒中拌合物的上表面坍落某定高度时的经历时间来反映新拌混凝土的塑性粘度,设计了试验装置和试验步骤,建立了用坍落度和坍落50m m、100m m的时间来表征屈服应力和塑性粘度的半经验式数学模型,可以简便测试出新拌混凝土的流变学参数。改进式坍落度筒的测试范围为坍落度为50m m～300m m。经验证,改进式坍落度筒测试结果与粘度计测试结果吻合较好,验证了上述模型的正确性,利用上述模型。
Fludity is an impotant index of workability of fresh concrete. In this paper normal concrete fluidity testing method and new rheology testing method are combined and used in military high sock concrete mixes, a simple field test method intended to provide an evaluation of the two Bingham rheological parameters, yield stress and plastic viscosity, was developed. To determine the plastic viscosity the time necessary for the upper surface of the concrete in the standard slump cone to slump determined heights was measured. The apparatus and test procedure are described. Semi-empirical models are proposed for the yield stress and for the plastic viscosity as function of the final slump and 50mm and 100mm slumping time. The models can be used to measure the rheologci parameters. The application of the modified slump test is limited to concretes with a slump of 50 to 300 mm. It is found that the results of modified slump test and viscometer were well anastomotic and the former models were valid.
出处
《混凝土》
CAS
CSCD
北大核心
2006年第8期64-69,共6页
Concrete
关键词
高性能混凝土
流动性
流变
坍落度
坍落时间
high performance e concrete
fluidity
rheology
slump test
slump time
