蒸汽养护条件下纳米TiO2对粉煤灰水泥体系早期力学性能的影响

Influence of Nano TiO2 on the Early Mechanical Properties of Fly Ash Cement System under Steam Curing

关键词:  纳米TiO2  粉煤灰  水化特性  火山灰反应  微观结构

Key words:  nano TiO2  fly ash  hydration characteristic  pozzolanic reaction  microstructure

摘要:

研究了蒸汽养护条件下纳米TiO2（NT）对粉煤灰水泥体系早期力学性能的影响,并探索了其影响机制.结果表明：NT的掺入可显著提高粉煤灰水泥体系的早期抗压强度,其最佳掺量为3%;NT的掺入显著提高了水泥熟料的水化程度及粉煤灰的二次水化程度,增加了水化硅酸钙（C S H）凝胶的聚合度;NT的掺入降低了粉煤灰水泥体系的孔隙率及总孔容,改善了其孔径分布,从而提高了粉煤灰水泥砂浆的密实度及早期抗压强度.

Abstract:

The influence of nano TiO2(NT) on the early mechanical properties of fly ash cement system was investigated, and the mechanism was explored. The results show that the incorporation of NT can considerably improve the early compressive strength of the fly ash cement system and the optimum content of NT is 3%. In addition, NT can significantly enhance the hydration degree of cement clinker and the secondary hydration degree of fly ash, it can increase the polymerization degree of calcium silicate hydrate（C S H）gels, decrease the porosity and total pore volume, improve the pore size distribution, and thus increase the compactness and early compressive strength of the fly ash cement mortars.