High Performance Concrete With Fly Ash Pumping Pilot Study

This paper carried out the experimental and practical application study on the comprehensive characters of high performance pumping concrete containing coal ash, which was made by mixing different amounts of coal ash into the concrete, the main results as follows:The effects of coal ash quality on fluidity of mortar, concrete slump and concrete slump losses were studied, the result showed that the mortar without coal ash need more high-range water reducing agent to possess ideal fluidity with reducing the ratio of water to cement, mixing the good-quality and fine coal ash into the mortar can markedly improve the mortar's fluidity and reduce the amount of mixed water reducing agent. In addition, the coal ash can restrain the concrete slump losses. The different kinds of coal ash have obviously different influences on concrete slump and concrete slump losses because of the different fineness, water requirement ratio and ignition loss, and the fine coal ash with low ignition loss can more obviously restrain the concrete slump losses.By studying the effect of coal ash amount on concrete compressive strength and working performance, we can concluded that the concrete strength changed with mixing amount of coal ash in the early age, when the mixing amount of coal ash was about 20%, the 7-day concrete strengthen has almost no change, however the concrete strength decreased markedly in the early age when the mixing amount of coal ash was more than 30%, moreover the strength of concrete containing coal ash increased more rapidly in the later age, and when the mixing amount was less than 30%, the strength will increase with the mixing amount of coal ash increasing.Coal ash concrete possessed excellent working and stuffing performance, fluidity and was easily pumping...