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

本研究的目的是建立一级自密实高流动性混凝土可泵性的评价和改善方法。本研究项目采用以下两个系列的高流动性混凝土可泵性评价和改善新指标进行了试验研究：A）2003年通过循环管道进行现场泵送试验，B）2004年采用新拌混凝土变形性试验方法进行室内试验。现场试验的目的是通过现场实际泵送混凝土来测量新拌混凝土流经循环管道的压力损失。交换水平输送距离约为59.5m。本次现场试验对泵送过程中混凝土的状态进行了从稳定状态到堵塞状态的试验。压力计的数量为7个。坍落度为18cm的普通混凝土和具有自密实性的IV型粉煤灰高流动性混凝土 ...更多信息 试验采用了等级为1的捕集能力。利用泵送试验机对新拌混凝土的压力变化是否是抗脉动流离析的定量指标进行了试验研究。本次室内试验中，两种混凝土的配合比和材料与档案试验中的混凝土相同。从实验工作中得出以下结论。(1)在自密实1级大流动性混凝土变形性试验方法中，通过控制泵送试验机活塞的移动和停止，产生与实际泵送相同的脉动流。(2)通过对普通混凝土在泵送过程中的变形试验方法与实际泵送过程中的变形试验方法的比较，发现变形试验方法的压力损失大于实际泵送过程中的压力损失。因此，对于普通混凝土，变形性能的试验方法是安全的。另一方面，对于自密实能力为1级的高粘度大流动性混凝土，变形性试验方法的压力损失低于实际泵送的压力损失。少

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