The research on the evaluation and improvement method of pumpability of the high-fluidity concrete with the self-compacting ability of Rank 1

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A purpose of this study is to establish the evaluation and improvement method of pumpability of the high-fluidity concrete with the self-compacting ability of Rank 1.In this research project, the experimental tests have been conducted to take the new indexes for evaluation and improvement of pumpability of the high-fluidity concrete in two series as followed : A) Field pumping test through the circulated pipeline in 2003, B) Laboratory Tests by using the test method for deformability of fresh concrete in 2004. The objective of the field test was to measure the pressure loss of-fresh concrete flowing through the circulated pipeline by the actual concrete pumping on site. The exchanged horizontal conveying distance was about 59.5m. In this field test, the state of concrete in pumping was carried out from stable state to blocking state. The number of pressure gage was seven. Normal concrete having the slump of 18cm and the high-fluidity concrete with type IV of fly ash having the self-com … More pacting ability of Rank 1 were used in this field test. The objective of the laboratory tests was to examine whether the variation of the pressure of fresh concrete i s quantitative index of segregation resistance to pulsatile flow using a pumping tester. In this laboratory tests, the mix proportions and materials of the two concrete were same as those of the concretes in the files test. The fol lowing were concluded from the experimental work.(1) Pulsatile flow was generated as actual pumping by controlling move and stop of piston of pumping tester which used in test method of deformabi I i ty of the high - fluidity concrete with the self-compacting ability of Rank 1.(2) The comparison between test method of deformabi I i ty during pu l sat i l e flow and actual pumping in case of normal concrete, pressure loss of test method of deformabi I i ty is higher than pressure loss of actual pumping. So test method of deformability is considered to be safe in case of normal concrete. On the other hand, pressure loss of test method of deformability is lower than pressure loss of actual pumping in case of the high-fluidity concrete with the self-compacting ability of Rank 1 with high viscosity. Less