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

管内混凝土脉动流动变形性能恶化与离析定量指标研究

• 批准号: 13650508
• 负责人: HASHIMOTO Chikanori
• 金额: $ 2.62万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650508/
• 关键词: Pumpability; Field test; Pulsatile flow; Test method for deformability of fresh concrete using a pumping tester; Fly ash; Segregation; Fluctuation; Bent pipe; フレッシュコンクリート; 材料分離抵抗性; 変形性評価試験; 平均ポンプ油圧; 変動係数; フライアッシュIV種; 粗骨材濃度

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

本研究的目的是提前评估可泵送性，建立一种与压力下混凝土泌水试验方法相同的试验方法，以及使用泵送试验机对新拌混凝土的抗离析性进行变形试验方法。新拌混凝土在管道中流动的脉动流。在本研究项目中，对变形能力恶化和偏析的新指标进行了以下两个系列的实验测试：A）2001年实验室测试B）2002年现场测试。实验室测试的目的是检查新拌混凝土压力的变化是否是泵送试验仪抗脉动流离析性能的定量指标。为了检验所提出的指标在现场实际泵送混凝土中的适用性，进行了现场试验，通过试验工作得出以下结论：（1）粉煤灰混凝土的变形能力和抗离析能力比普通混凝土大，粉煤灰混凝土的稳定泵送和不稳定泵送范围比普通混凝土大(2)粉煤灰混凝土与普通混凝土的稳定泵送范围不同,粉煤灰混凝土的平均泵油压力高于普通混凝土。普通混凝土，但泵油压力的波动比普通混凝土小。(3)对于坍落度12-8cm的混凝土，弯管的脉动波动(变化指数)比脉动大10倍以上直管内 (4) 取从波谷部到波谷部的 1 个脉动形成时间的压力变化指数来量化脉动是有效的。 由上可知，变化指数之间存在相关性。使用泵送测试仪和波动现场脉动测试新拌混凝土变形能力的测试方法所提供的压力