自密实混凝土工作性测试方法

为了推动自密实混凝土的工程应用,发展自密实混凝土工作性的标准化测试方法非常必要.开发了一种自密实混凝土工作性的测试仪,并由此发展了相应的测试方法,该测试方法通过测试混凝土的流出时间、动态扩展度以及动态离析率3个参数来反映自密实混凝土的工作性.试验结果验证了这种新的方法能够有效地评价和反映自密实混凝土的工作性.与已有的方法相比,该新方法具有简单易操作的特点,而且能够反映混凝土拌合物动态情况下的工作性.

TEST METHOD FOR WORKABILITY OF SELF-COMPACTING CONCRETE

In order to further promote application of self-compacting concrete (SCC), a standard method for testing workability of SCC is indispensable. A new test apparatus is developed and thus a new test method for workability of fresh SCC is presented. This new method reflects the workability of fresh SCC by testing three parameters of outflow time and dynamic flow spread value and dynamic segregation ratio. Experiments are carried out to examine the workability such as flowability, passing capability and segregation resistance of fresh SCC mixtures by use of this new method. And the segregation resistance of fresh SCC is assessed by dynamic segregation ratio measured by vibration wet sieving test. Comparatively, value of slump and slump-flow of corresponding fresh SCC are tested by use of slump cone. Preliminary results indicates this new test method is valid in evaluating workability of fresh SCC mixture and the corresponding parameters can reflects generally the workability including flowability, passing capability and segregation resistance of SCC mixture. This new method is also simple and convenient compared with other existed test methods.