低钙粉煤灰活化制备防水涂料的试验研究

粉煤灰是燃煤电厂排放的粉状固体废弃物,已带来诸多的生态、环境问题。文章以攀枝花电厂低钙粉煤灰为原料,通过对其改性、化学激发制备具有较好防水效果、高掺量、高附加值的水泥基粉煤灰防水涂料。研究了粉煤灰改性、化学激发,以及同时改性与化学激发三种状况下所形成的粉煤灰防水涂料产品性能。研究了硫酸盐、硅酸盐两种化学激发剂体系下粉煤灰防水涂料性能。通过微观XRD、SEM分析,研究了粉煤灰的活化效果。结果表明:粉煤灰经表面改性后,改善了涂料的和易性,抗渗压力比原灰提高67%,比化学激发灰提高了25%。粉煤灰经同时表面改性与化学激发后抗渗能力比原灰提高了127%。硫酸盐激发体系活化效果好于硅酸盐体系。经硫酸盐体系活化的粉煤灰防水涂料15d的抗压强度、抗折强度、抗渗压力,以及渗透压力比均高于GB18445-2001标准28d值。

Experimental Study on Activation and Preparation of Waterproof Coating of Low Calcium Fly Ash

Fly ash as one of industrial solid wastes in coal fired power plant causes more and more serious ecological problem and environmental pollution. Cement-based fly ash waterproof coating with good water proof effect,high volume and high value-added was prepared by surface modification and chemical activation with low calcium fly ash of Panzhihua Power Plant. Influence of factors including modification,chemical activation of fly ash and simultaneous action of modification and chemical activation on performance of coating products were investigated. Effect of sulfate and silicate generating system on the performance of coating was also studied. Activation effect of fly ash was analyzed by micro-XRD and SEM. Results showed that fly ash could improve coating workability by surface modification,with impermeability stress increased by 67% compared with that of raw ash,and increased by 25% compared with that of chemical activation. Permeability ability of fly ash by both surface modification and chemical activation was significantly improved by increasing of 127% correspondingly compared with that of raw fly ash. Activation effect of sulfate generating system was better than those of silicate generating system,with impermeability stress of 15d and chemical activation higher than those of 28d standard in GB18445-2001.