几种化学物质对粉煤灰水泥活性激发效果

Activation effectiveness of some chemical substances for Portland cement blended with fly ash

借助于水泥砂浆试样的抗压强度跟踪测试,考察了几种无机化学物质对粉煤灰水泥的活性激发效果,同时借助于对水泥硬化体样品的XRD测试和SEM观察,深入通探讨了添加激发剂的粉煤灰水泥硬化体的水化产物和微观结构特征。试验结果表明:激发剂显著促进了粉煤灰水泥的活性激发,尤其是早期活性,水泥强度显著提高;XRD测试和SEM观察也表明,与空白样品相比,掺加激发剂的粉煤灰水泥硬化体明显表现出致密化的结构特征,粉煤灰颗粒表面趋向于粗糙化;Ca(OH)2衍射峰和石英衍射峰明显减弱,表明在激发剂作用下粉煤灰中的活性成分与水泥水化放出的Ca(OH)2之间化学反应得到了加剧。

The activation effectiveness of some inorganic chemical substances on Portland cement blended with fly ash was investigated by means of compressive strength determination for the comment mortar specimens.Meanwhile,the characteristic of the hydration products and the microstructure of the hardened cement paste of the Portland cement blended with fly ash were also studied by means of XRD analysis and SEM observation.The results shows that activators used enhance the evolution of reactivity of the fly ash, especially at early age,hence increasing the strength of the cemant.XRD analysis and SEM observation also show that hardened cement paste blended with fly ash and added with activator presents denser microstructure feature, surface of the fly ash particles tend to be coarser, as compared with that of reference speciman.At the same time,the reduction of the intensity of the diffraction peak of portlandite and quartz indicates that the chemical reaction between the active component in fly ash and portlandite released from the hydration of cement is enhanced under the presence of activator.