用低等级湿排灰配制中低强度混凝土的试验研究

以生石灰、生石膏为激发剂,采用化学激发、水热激发与机械磨细相结合的高效复合活化技术对低等级湿排粉煤灰进行活化处理,可得到高活性粉煤灰掺合料。用此掺合料,掺入高效减水剂,配制出高掺量粉煤灰C20~C40中低强度混凝土,粉煤灰取代水泥率可达到40%~50%,试样7d抗压强度与基准混凝土相当,28d与60d抗压强度达到或超过基准混凝土。

Experimental Study on Preparing Middle-and-Low Strength Concrete with Low Grade Wet Fly ash

The highly active fly ash admixture was obtained by activation treatment of low grade wet fly ash with efficient composite activating techniques of chemical activation,hydrothermal activation and mechanical grinding,using quicklime and raw gypsum as activators.The middle-and-low strength concrete C20~C40 of high fly ash content was then prepared by adding the fly ash admixture and water reducer to the concrete grout,in which the ratio of fly ash replacing cement could account for 40%~50%.The resulting product can compare to the primary standard concrete in teams of the 7d compressive strength,and even exceed it in terms of the 28d and 60d compressive strength.