低活性粉煤灰表面胶凝性能改善研究  

Improvement of Surface Cementitious Properties of Low Activity Fly Ash

作　　者：刘向阳[1] 张同生[1] 张平平[1] 韦江雄[1] 余其俊[1] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640

出　　处：《硅酸盐通报》2014年第7期1655-1661,共7页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(U1134008;51072058)

摘　　要：低活性粉煤灰颗粒与水化产物界面粘接不良，是导致粉煤灰水泥强度等性能较差的根本原因。本文将预水化的低活性粉煤灰在适宜温度下进行热处理，利用粉煤灰颗粒表面水化产物脱水相可再水化的原理，达到改善粉煤灰颗粒与水化产物的界面粘结性能。探讨了处理温度、粉煤灰粒度、预水化程度：等参数对粉煤灰活性指数的影响。结果表明：在750℃处理时，粉煤灰表面水化产物分解生成低结晶度β-C2S，该矿物可再水化，进而改善了粉煤灰颗粒与水化产物的界面粘结。预水化程度为5％～6％（水化深度0．22～0．27μm）时，处理后粉煤灰活性指数最高。该方法对粗粉煤灰活性改善效果较好，且对早期活性指数的提高幅度较大。Due to poor bonding between fly ash particles and hydration products, blended cements with fly ash usually show lower compressive strengths, especially at early ages. Surface cementitious properties of fly ash were improved by dehydration and rehydration processes of hydration products on the surface of fly ash particles. The results show that during the calcination at 750 ℃, C-S-H gel is mainly transformed into a less crystalline C2 S, leading to improved bonding between fly ash particles and hydration products due to rehydration of new generated C2S. The proper pre-hydration degree of fly ash was 5% -6% , and this method is particularly suitable for improving the compressive strength index of coarse fly ash at early ages

关 键 词：低活性粉煤灰 表面胶凝性 活性指数 水化产物脱水相 

分 类 号：TQ172[化学工程—水泥工业]