煤矸石胶凝材料水化产物及聚合度分析

来源期刊：中南大学学报(自然科学版)2011年第2期

论文作者：张吉秀 孙恒虎 万建华 张娜

文章页码：329 - 335

关键词：煤矸石；硅铝基胶凝材料；聚合度；水化产物

Key words：coal gangue; cementitious materials; polymerization degree; hydrates

摘    要：采用XRD，IR和NMR等分析方法研究北京房山煤矸石在水化过程中的物相及²⁹Si聚合度的变化规律。在²⁹Si NMR基础上提出利用相对桥氧数(RBO)评价硅氧多面体聚合度的方法，并用该方法研究煅烧煤矸石在活化及水化前后的RBO变化规律。研究结果表明：煤矸石中的粘土矿物绿泥石和白云母等在活化过程中发生分解，表征硅氧多面体聚合度的指标RBO明显降低；而在水化过程中随着水化龄期的增加，氢氧化钙不断与硅铝质物料中的[SiO₄]和[AlO₄]四面体发生反应，生成水钙沸石和碳硅钙石，导致RBO升高，浆体材料的结构致密性增加。这表明煤矸石中的[SiO₄]聚合度在煅烧活化过程中由高聚合度向低聚合度转变，在水化过程中则由低聚合度向高聚合度转变，聚合度或RBO的变化在一定程度上反映活化效果和胶凝活性的发挥程度。

Abstract: XRD, IR and NMR technique were used to study phase transition and ²⁹Si polymerization degree of hydrates in coal gangue added cement. A new method of the relative bridge oxygen (RBO) was proposed based on NMR technique to evaluate the polymerization degree of ²⁹Si in thermo activated coal gangue and hydrates of gangue added cement. The results show that the clay minerals such as leuchtenbergite and muscovite decompose and the RBO correspond to [SiO₄] degree of polymerization decreases in thermo-active process. But in hydration process calcium hydroxide reacts with [SiO₄] and [AlO₄] tetrahedron which make calcium hydroxide phase decrease and generate gismondinte and larnite. [SiO₄] polymerize to each other and RBO increases significantly. Meanwhile the density of paste increases with hyaration age. So the thermo-activation and hydration is the process of [SiO₄] depolymerization and polymerization respectively. The changes of ²⁹Si polymerization degree-RBO can be used to evaluate the coal gangue cementitious activity or hydration degree.