结构异质化纳米SiO2对碱钢渣基材料碱激发-水化协同反应调控机制研究

为顺应现代工程对建筑材料高耐久、长寿命的要求，碱激发材料面临着迫切的改性需求。本项目在纳米SiO2可显著提高胶凝材料密实度、优化凝胶组成的研究基础上，将其用于碱钢渣基材料的改性。采用溶胶凝胶法和乳液聚合法在纳米SiO2表层附上其它纳米材料壳结构，通过调整合成温度、PH值、反应时间等，控制壳结构的厚度，制备反应活性可控的结构异质化纳米SiO2，优化改性措施；测试碱激发-水化协同反应热和反应不同时期产物的特征，理论推断碱激发、水化的反应过程和程度，以此探讨纳米SiO2对碱激发-水化协同反应的作用及调控机制，控制改性进程；采用染色法或荧光示踪法分析纳米SiO2在胶凝材料中的分散性和对凝胶的物理填充、化学键合作用，并重点探讨其对凝胶Ca/Si比的影响，确定凝胶改性目标；测试纳米改性碱钢渣基材料的性能，分析改性效果。项目研究结果将为纳米SiO2对碱激发材料的深入改性研究提供新的方法和思路。

In order to adapt to modern engineering demand for high durability and long service life of building materials, alkali-activated materials face the urgent modification requirements. It has been suggested that nano SiO2 can greatly improve the packing density of cementitious materials and optimize the chemical components of gel. In this project, the improvement of alkali-activated steel slag materials quality is going to be studied with the modification effect of nano SiO2. Other nano materials as shell structure are used to be attached to the surface of nano SiO2 as core structure by sol gel method and emulsion polymerization method. By adjusting temperature, PH value, reaction time and so on to control the structure and thickness of shell structure, the core-shell type nano material which has controllable reactivity is prepared, thereby optimizing the modification measures. The reaction process and degree of alkali activation and hydration are theoretically inferred through measuring the alkali activation - hydration synergy reaction heat and the characteristics of reaction products in different times, based on this to discuss the action and regulatory mechanism of nano SiO2 on the alkali activation - hydration synergy reaction, in order to control the modification process. The dispersibility of nano SiO2 in the cementitious materials and its physical filling, chemical bonding on the gel are analyzed using the fluorescent tracing technique, and the effect of nano materials on the Ca/Si ratio of gel is mainly discussed, so as to determine the modification target of gel. The performance of alkali-activated steel slag concrete which is modified by the nano SiO2 is measured, in order to reflect the modification effects. It is expected that these studies may provide new method and new idea for the further in-depth study of the nano-materials modification on alkali-activated materials.