Strength sensitivity and failure mechanism of full tailings cemented backfills

Abstract

Full tailings cemented backfills were produced by taking Daye iron ore tailings as a raw material and cement as a cementing material.The relations of the backfills' strength with slurry concentration,sand-to-lime mass ratio and curing period,together with the sensitivity of the backfills' strength to these influencing factors,were studied by using single-factor five-level experiment design.The strength of the backfills follows an exponential function with slurry concentration and curing period,but a linear function with sand-to-lime mass ratio.Moreover,the sensitivity of the backfills' strength to curing period is the highest,but is the weakest to sand-to-lime mass ratio.Compressive failure test results show that destruction of the backfills goes through four stages,including micro-crack closure stage,linear elastic stage,micro-crack propagation stage,and crack coalescence stage.