作　　者： ; ; ; ;

机构地区： 中南大学土木工程学院

出　　处： 《中南大学学报（自然科学版）》 2012年第10期4022-4028,共7页

摘　　要： 参照工程化水泥基复合材料（ECC）的设计思路，制备PVA纤维增强砂浆，并使养护成熟的砂浆在不同荷载下预损伤，利用阻抗谱法测试不同频率CO时预损伤试件的交变电流响应，得到水泥基材料的交流阻抗特征曲线，对特征曲线进行数学分析得到表征渗流参数的水力半径（h）、迂曲度（T）双电层电容（C）和电荷传递电阻（Rct]。渗流结构参数可以间接反映荷载损伤浆体的孔隙结构变化。基于Menger海绵理论利用压汞法（MIP）得到损伤浆体的孔分形维数、孔隙率和孔累积分布；利用低温氮吸附法（BET），并结合开尔文方程对损伤浆体吸附分支与脱附分支特点进行分析。实验结果表明：预压力在峰值荷载的40％～50％之间时，浆体的细微观孔隙结构开始发生明显变化，损伤浆体的吸附等温线属于第Ⅱ类曲线。 According to preparing process of ECC, PVA reinforced mortar was prepared and cracked after mature, AC impedance characteristic curves of mortar obtained through testing alternating current response at different frequencies by impedance method. From the characteristic curves, percolation parameters （h, T, C, Rot） were calculated by mathematical analysis, and the parameters reflect the evolvement of pore structure indirectly. Fractal dimension, porosity, and cumulative pore distribution of pre-cracked mortar were analyzed by MIP method. At last, Characters of adsorption branch and desorption branch of cracked mortar were analyzed by BET method. The results show that pore structure changes clearly after 40%-50% peak load, and adsorption isotherm of pre-cracked mortar belongs to Type Ⅱ isotherm.

关 键 词： 砂浆 渗流结构 压汞法 氮吸附法

领　　域： [建筑科学]