Study on Effects Utilization of the Fly Ash Produced from Imported Coal for Concrete

点击翻译按钮获取中文摘要

The purpose of this paper is to investigate the utilization of fly ash produced from foreign coal on concrete. The investigation includes the physical and chemical properties of various types of fly ash, the properties of the concrete with fly ash. The effects of high fluidity concrete using superplasticizer together with fly ash, and the possibilities of using high volume fly ash on high afluigity concrete.The results obtained inthis proper are summarized as follows :1) The qualities of fly ash are highly infuenced by the producing condition and buming temperature of coal. And the fundamental properties of concerete containing fly ash are affected by specific surface area, ignition loss, and SiO_2 from fly ash. The change i the quality of concerete containing classified fine fly ash tends to be lower than the case with base fly ash.2) The amounts of superplasticizer used are calculated correspondingly to asdorption of methylene blue, ignition loss, and specific surface area. The change of air content with time is affected by the types of fly ash, and slum loss increases as air content decreasses. Classified fine fly ash is 2-3times as quanity of superplasticizer to give a certain air content as base fly ash.3) The strength of fly ash concrete is higher than that of fly ash free concrete at the long term stages (182days). Strength development is mainly affected by the specific surface areea and SiO_2 from fly ash. Drying shrinkage is inflyenced by the kinds fly ashes and shapes of fly ash. Concrete with fly ash is trendency to increase the drying shrinkage.4) High fluidity with classified fine fly asj are affected by the kinds of superplasticizers and fly ashes, and the property of fresh and hardened high fluidity concrete is good quality. The amount of superplasticizer use is calculated correspondingly to the flowability of concrete.