矿渣掺量及激发剂模数对偏高岭土基地聚物常温固化的影响

将粒化高炉矿渣(GGBFS)掺入偏高岭土(MK)中,研究了矿渣掺量对具有常温固化能力胶凝材料稠度、凝结时间及力学性能的影响,并通过X射线衍射(XRD),傅里叶变换红外光谱(FTIR),扫描电镜(SEM)等分析手段研究了偏高岭土-矿渣复合体系的反应机理.结果表明:将矿渣掺入偏高岭土能减小浆体的稠度,缩短其凝结时间;偏高岭土-矿渣复合体系可在常温下固化,得到具有较高强度的硬化浆体;在碱激发作用下偏高岭土-矿渣复合体系发生了地质聚合反应和矿渣水化反应,生成了N-A-S-H凝胶与C-S-H凝胶共存的结构;激发剂模数和偏高岭土与矿渣的质量比是影响反应产物强度的主要因素——矿渣掺量不高于40%(质量分数)时,反应产物的强度随激发剂模数增大而降低;矿渣掺量超过60%后,反应产物强度随激发剂模数增大而提高.

Influence of GGBFS Content and Activator Modulus on Curing of Metakaolin Based Geopolymer at Ambient Temperature

Ground granulated blast furnace slag(GGBFS) was used to substitute for part of metakaolin, to obtain the cementitious material being able to cure at ambient temperature. The technical methods of XRD, FTIR, and SEM were employed to study the reaction mechanism of the metakaolinGGBFS compound material. The results show that the viscosity and the curing time of the alkaline activated paste will be reduced by adding GGBFS into metakaolin. The hardened binder with substantial compressive strength can be obtained by activating the compound of metakaolin and GGBFS at ambient temperature. The results by XRD and FTIR reveal that the N A S H gel by geopolymerization of metakaolin and the C S H gel by hydration of GGBFS are generated simultaneously during the activation process of the compound system. The activator modulus(SiO2Na2O ratio) and the mass ratio of metakaolin and GGBFS are the prime factors which influence the mechanical properties of reaction products, because the compressive strength of hardening paste decreases with the increase in activator modulus when the mass ratio of GGBFS is less than 40%, while it increases with the increase in activator modulus when the GGBFS ratio exceeds 60%.