超高性能水泥基灌浆料的孔结构特征

基于水泥-硅灰-矿粉三元胶凝体系，在超低水胶比条件下制备超高性能水泥基灌浆料（UHPCG），并采用压汞法分析其不同水化龄期的孔体积分布曲线、孔结构特征参数和孔径分布，研究孔结构特征。结果表明，在超低水胶比条件下，UHPCG的总孔隙率较低，且随着水化龄期延长，孔径趋于细化，结构也更密实。在标准养护28d龄期条件下，UHPCG的总孔隙率低至4.14%，平均孔径低至15.5nm，最可几孔径低至12.2nm。当标准养护龄期由1d增至28d时，小于20nm的无害凝胶孔在孔径分布中的比例大幅增长，大孔向无害凝胶孔转移，孔径分布趋于向无害凝胶孔集中，有利于提高其强度和耐久性。

Pore structure characteristics of ultra-high performance cement-based grouting materials

Based on cement - silica fume - mineral powder ternary gelling system, ultra-high performance cement-based grouting materials (UHPCG) with ultra-low water-to-binder (W/B) ratio are prepared, and the pore structure characteristics are investigated through the analysis of the pore volume distribution curve, characteristic parameters and pore diameter distribution at different hydration ages by mercury intrusion porosimetry. The results show that with ultra-low W/B ratio, the total porosity of UHPCG is lower, and as the hydration age prolongs, the pore diameter tends to refine and the structure becomes more dense. Under standard curing conditions of 28-day, the total porosity of UHPCG is as low as 4.14%, the average pore diameter is as low as 15.5nm, and the most probable pore diameter is as low as 12.2nm. When the standard curing age increases from 1-day to 28-day, the proportion of harmless gel pores of less than 20nm increases significantly, the large pores transfer to harmless gel pores, and the pore diameter distribution tends to focus on harmless gel pores, which is beneficial to improve its strength and durability.