粉煤灰水泥体系中粉煤灰活性的化学激发  

Study on the Chemical Activation of Fly Ash in Fly Ash Blended Portland Cement System

作　　者：栾晓风[1] 潘志华[1] 王冬冬[1] 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009

出　　处：《硅酸盐通报》2010年第4期757-761,783,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家973项目资助(2009CB623104)

摘　　要：本文借助于水泥物理性能试验和XRD测试手段就NaOH、Na2SO4和Na3PO4.12H2O三种不同阴离子钠盐的添加对粉煤灰水泥中粉煤灰活性的激发作用进行了比较性研究。结果表明,粉煤灰水泥中添加适量NaOH,Na2SO4和Na3PO4.12H2O均能有效地激发粉煤灰的活性,这个适宜掺量分别为NaOH:0.5%,Na2SO4:3.0%和Na3PO4.12H2O:2.0%。在适宜掺量下,NaOH添加可使水泥3 d和28 d抗压强度分别提高6.8%和7.7%;添加Na2SO4则对早期强度激发效果显著,3 d抗压强度可提高18.2%;Na3PO4.12H2O则对后期强度激发效果显著,28 d抗压强度可提高17.7%。XRD分析表明,上述三种化学物质的添加均引起了粉煤灰中石英衍射峰和水泥硬化体中Ca(OH)2衍射峰的降低,说明它们都在不同程度上促进了水泥水化放出的Ca(OH)2与粉煤灰中的酸性氧化物的反应,从而加剧粉煤灰潜在活性的释放。Comparative study was carried out on the effect of three chemical activators with different anions on the activation of fly ash in fly ash-Portland cement clinker system by means of physical property test and XRD analysis. Results show that addition of these three chemical activators in an appropriate dosage promotes the activation of fly ash significantly. The optimum dosage is NaOH 0.5% at which the increase of 3 d and 28 d compressive strength of the cement mortar is 6.8% and 7.7% respectively, and Na2SO4 3.0% at which the increase of 3 d compressive strength is 18.2% , and Na3PO4·12H2O：2.0% at which the increase of 28 d compressive strength is 17.7%. XRD analysis reveals that addition of the chemical activators causes reduction of the intensity of the diffraction peaks responsible for quartz in fly ash and Ca （OH）2 in hardened cement paste, originated from the hydration of cement and the which suggests that the reaction between Ca （OH）2 acidic oxides originated from fly ash is enhanced, accelerating the evolution of the potential reactivity of fly ash.

关 键 词：粉煤灰 水泥 激发 强度 

分 类 号：TQ172[化学工程—水泥工业]