Effect of different particle size distribution of zeolite on the strength of cemented paste backfill

Abstract

Cemented paste backfill system used for the storage of tailings underground also serves as support against subsidence due to roof loads. Therefore, paste backfill materials should be optimized according to strength, environment, and cost requirements. The main purpose of this study is to determine the ratio and optimal particle size distribution of zeolite which is one of the natural pozzolanic materials and can substitute cement in paste backfill. As a result of the experiments without zeolite, it was determined that paste backfill materials with the cement ratio of 9% and 11% can be used for ground support instead of the cemented paste backfill reference samples with 80% solid content. Then, zeolite-substituted samples were prepared in 2 different particle sizes of - 90 mu m and - 180 mu m at cement ratios of 5%, 10%, 15%, and 20%. Then, the effects of the paste backfill materials on the strength of curing periods of 28, 56, and 90 days were examined. As a result, it was found that 9% cemented paste backfills with 15% zeolite substitutes (- 90 mu m) and 11% cemented paste backfills with 10% zeolite substitutes (- 180 mu m) could be used in paste backfill. Also, 11% cemented paste backfills with 10% zeolite substitutes (- 180 mu m) provide better strength depending on the curing times.