Effects of curing time and ice-to-water ratio on performance of cemented paste backfill containing ice slag

With the continuous development of mining-with-backfill technology, more requirements are proposed for the utilized backfill materials, such as cold-loading, heat-saving, energy-storing, and seepage-proofing. In this paper, a new type of backfill material was proposed by introducing ice into cemented paste backfill (CPB), which is referred as the iced CPB (ICED_CPB) technology. Such an ICED_CPB technology can be used to meet the challenges in hot workplaces that are being frequently encountered as the mining depth increases. The performance of ICED_CPB under the coupled effect of curing time and ice/water ratio (IWR) was investigated experimentally. Some factors affecting the performance of CPB, such as the number of pores (N), porosity fractal dimension (D-c), roundness (RD), permeability (K), unconfined compressive strength (UCS), electrical resistivity (ER) and longitudinal wave velocity (V-L) were investigated and their relationships were discussed. The results indicate that the optimum IWR was determined to be 1.2 for the ICED_CPB system in this study. The influence of IWR on N, D-c, K followed a decrease-then-increase pattern while followed an increase-then-decrease pattern on RD, UCS, ER and longitudinal wave velocity. N, D-c, and K increased while RD, UCS, ER and longitudinal wave velocity decreased with increasing curing time. (C) 2019 Elsevier Ltd. All rights reserved.