摘  要：基于低场核磁共振技术，研究了聚丙烯纤维掺量分别为0、0.6 kg/m3、0.9 kg/m³和1.2 kg/m³以及粗骨料取代率为40%的煤矸石混凝土在冻融作用下T2谱面积的分布与变化特征、内部微观孔结构分布特性以及孔隙冻融损伤规律。结果表明，随着冻融循环次数的增加，T2谱整体呈右移趋势，即向大孔隙方向偏移，且T2谱面积逐渐增大的同时第一峰面积所占百分比在减小，第二峰和第三峰面积所占百分比在增加，表明冻融循环使煤矸石混凝土内部的大孔隙大幅增加，内部出现了明显的冻融损伤；0.6 kg/m³的聚丙烯纤维对煤矸石混凝土内部孔隙的细化作用最好。

Abstract: Based on low-field nuclear magnetic resonance(NMR), the T2 spectrum distribution, T2 spectrum area variation, internal micro-pore structure distribution and pore freeze-thaw damage law of coal gangue concrete with 40% replacement rate of coarse aggregate and with 0, 0.6 kg/m³, 0.9 kg/m³ and 1.2 kg/m³ polypropylene fibre content under freeze-thaw cycles were studied. The results show that with the increase of freeze-thaw cycles, the whole T2 spectrum shifts to the right direction, that is to the direction of macro-pore, and with the area of T2 spectrum increases gradually, the percentage of the first peak area decreases, while the percentages of the second and third peak area increase, which indicates that the freeze-thaw cycle greatly increases the macro-pore in coal gangue concrete and causes obvious freeze-thaw damage. When the content of polypropylene fibre is 0.6 kg/m³, the fining effect on the internal pore of gangue concrete is the best.