Study on Quantitative Indexes for Deterioration of Deformability and Segregation on Pulsatile Flow of Concrete Flowing in Pipe

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A purpose of _this study is for ahead of time evaluation of pumpability to build a test method to be able to same as a test method for bleeding of concrete under pressure and a test method for deformability of fresh concrete using a pumping tester on segregation resistance to pulsatile flow of fresh concrete f lowing in pipe. In this research project, the experimental tests have been conducted to take the new indexes for Deterioration of Deformability and Segregation in two series as followed : A) Laboratory Tests in 2001 B) Field Test in 2002. The objective of the laboratory tests was to examine whether the variation of the pressure of fresh concrete is quantitative index of segregation resistance to pulsatile flow using a pumping tester. In order to examine the applicability of the proposed index to the actual concrete pumping on site, the filed test was conductedThe following were concluded from the experimental work(1) The deformability and segregation resistance of fly ash concrete has larger than that of normal concrete and the range of stable pumping and unstable pumping of fly ash concrete has larger than that of normal concrete(2) The range of stable pumping of fly ash concrete and normal concrete are different and the average pump oil pressure of fly ash concrete is higher than that of normal concrete, but the a fluctuation of pump oil pressure becomes smaller than that of normal concrete(3) About the concrete of the slump 12-8cm, and fluctuation (a variation index) of pulsation with a bent pipe is larger than 10 times in comparison with pulsation in straight pipe(4) It is effective to take the variation index of pressure by one pulsation form time from a valley department to a valley department to quantify the pulsationAs a result of above, there is correlation in a variation index of pressure to be provided by a test method for deformability of fresh concrete using a pumping tester and fluctuation on-site pulsation