煤矿安全2019，Vol.50Issue(9)：75-78,4.DOI:10.13347/j.cnki.mkaq.2019.09.019
基于NMR技术的充填体孔隙结构的冻融损伤演化特征
Characteristics of Freeze-thaw Damage Evolution of Pore Structure in Backfill Material Based on NMR Technology
摘要
Abstract
To study the evolution rule of pore structure in backfill material under freeze-thaw cycles, the nuclear magnetic resonance(NMR)technique was used to scan the meso-structure damage after 0, 50, 100 and 200 freeze-thaw cycles to obtain the relaxation time T2 spectrum of NMR. The laws of pore evolution and the mechanism of meso structure damage were analyzed. The results show that the variation of T2 distribution curves reflects the evolution and expansion characteristics of the pores in the samples under freeze-thaw cycles; with the increase of freeze-thaw cycles, the T2 spectral area which characterizes the porosity of the materials increases rapidly at the initial stage and decreases at the later stage, and the proportion of small pores increases with the number of cycles. With the increase of cycles, the ratio of macro-pores increases with the increase of the number of times. Through the discussion of the evolution mechanism of pore structure, it is pointed out that the joint failure due to the combined action of osmotic force and frost heave force in freeze-thaw cycles is the fundamental reason for the formation of the connecting fracture.关键词
充填混凝土/核磁共振/冻融循环/孔隙结构/损伤演化特征Key words
backfill concrete/nuclear magnetic resonance(NMR)/freeze-thaw cycles/pore structure/characteristics of damage evolution分类
矿业与冶金引用本文复制引用
杜晓方..基于NMR技术的充填体孔隙结构的冻融损伤演化特征[J].煤矿安全,2019,50(9):75-78,4.基金项目
河南省科技厅自然科学基金资助项目(142102310151) （142102310151）
