Strength sensitivity and failure mechanism of full tailings cemented backfills

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.