Experimental investigation on the relationship between pore characteristics and unconfined compressive strength of cemented paste backfill
Experimental investigation on the relationship between pore characteristics and unconfined compressive strength of cemented paste backfill
复制标题
胶结膏体充填体孔隙特征与无侧限抗压强度关系试验研究
DOI：
10.1016/j.conbuildmat.2018.05.224
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发表时间：
2018-08-10
影响因子：
7.4
通讯作者：
Song, Ki-Il
中科院分区：
文献类型：
--
作者：
Liu, Lang;Fang, Zhiyu;Song, Ki-Il
采用核磁共振（NMR）和扫描电镜（SEM）等技术表征了CPB试样的孔结构特征，并研究了无侧限抗压强度（UCS）与胶结充填体（CPB）孔结构特征之间的关系。结果表明，CPB试样中的孔隙主要是小的，“非损伤”的，约占70体积%的CPB试样中的所有孔隙。虽然“损伤”和“多重损伤”孔隙仅分别占总孔隙的3.93vol%和6.99vol%，但它们对CPB试样的UCS有显著影响。随着固化时间的延长，CPB试样的孔隙率逐渐降低（固化3d、14d和28d试样的平均孔隙率分别为11.07vol%、8.58vol%和7.09vol%）。此外，CPB试样的孔隙率也随着CPB浆料固相浓度的增加而降低。拟合分析表明，CPB试样的UCS与孔隙率呈指数负相关，与分形维数呈线性负相关。研究表明，利用核磁共振技术研究CPB试样力学性能与孔隙特征之间的关系是可行的。(C)2018爱思唯尔有限公司版权所有。
In this paper, the pore structure characteristics of CPB specimens were characterized using nuclear magnetic resonance (NMR) and scanning electronic microscopy (SEM) techniques, and the relationship between the unconfined compressive strength (UCS) and the pore characteristics of cemented paste backfill (CPB) was investigated. The results showed that the pores in CPB specimens were mainly small, "non-damaging" ones, which accounted for about 70 vol% of all pores in CPB specimens. Although the "damaging" and "multi-damaging" pores only accounted for 3.93 vol% and 6.99 vol% of all pores respectively, they had significant impacts on the UCS of CPB specimens. With the increase of curing time, the porosity of CPB specimens decreased gradually (i.e. the average porosities of CPB specimens at the curing time of 3 d, 14 d and 28 d were 11.07 vol%, 8.58 vol% and 7.09 vol%, respectively). Besides, the porosity of CPB specimens also decreased with the increase of solid concentration of CPB slurry. On the basis of fitting analysis, it could be observed that there was a negatively exponential relationship between the UCS and the porosity of CPB specimens and a linearly inverse relationship between the UCS and the fractal dimension. Our study demonstrates that it is feasible to study the relationship between mechanical properties and pore characteristics of CPB specimens by using the NMR technique. (C) 2018 Elsevier Ltd. All rights reserved.