不同养护条件下水泥基材料的孔隙结构

Pore Structure of Cement-Based Material under Different Curing Conditions

对于不同水胶比的水泥基材料，使用压汞法研究了其在饱水养护和密封养护条件下孔隙结构的特征．结果表明：养护条件对水泥基材料的孔径分布影响明显．与饱水养护相比，密封养护能显著增加RⅢ区间（100～1000nm）的孔隙含量（质量体积），降低RI区间（〈10nm）的孔隙含量；密封养护会降低水泥基材料的比表面积，增加净浆的孔隙率（体积分数），但对砂浆孔隙率的影响较不明显．胶凝材料中的磨细高炉矿渣（质量分数为65％）和硅粉（质量分数为5％）不能完全抑制孔隙自干燥导致的孔隙连通作用．

The influences of curing conditions on the pore structure of cement-based material with different water-binder ratios were investigated via mercury intrusion porosimetry（MIP）. The results show that cu- ring condition has substantial influence on the pore structure of cement-based material. Compared to the saturated curing, the sealed curing increases the pore content（mass volume） in 100 - 1 000 nm but decrea- ses that in 〈10 nm. By sealed curing the specific surface area of cement-based material is decreased, while the porosity（by volume） for pastes is increased, but the porosity for mortars has less obvious change. The secondary cementitious material, ground granulated blast furnace slag（65%, by mass） and silica fume （5%, by mass）, show limited capacity to resist the pore percolation by self-desiccation.