Chemically induced changes in the geotechnical response of cementing paste backfill in shaking table test

Abstract

Abstract Cemented paste backfill (CPB) is extensively used for underground mine support and/or tailings management. However, CPB behavior under cyclic loadings might be affected by the chemistry of its pore-water, which often contains sulphate ions. Till today, no studies have addressed the effect of sulphate on the response of CPB to cyclic loadings by using shaking table technique. This study presents new findings of assessing the effect of the sulphate in the pore water of CPB on its geotechnical response to cyclic loading by using shaking table. CPB mixtures were prepared (with and without sulphate), poured into a flexible laminar shear box, cured to 4 h, and then exposed to cyclic loading using one-dimensional (1D) shaking table. Several parameters (e.g. pore water pressure, settlement, lateral deformation, acceleration, electrical conductivity, effective stress, and liquefaction susceptibility) were monitored or determined before, during, and after shaking. Obtained results indicate that the sulphate-bearing CPB cured to 4 h can be prone to liquefaction under the studied conditions. However, sulphate-free CPB samples are resistant to liquefaction. These results are expected to contribute to a better understanding of the effect of water chemistry on the cyclic behavior of CPB, consequently enhancing the cost-effective design of CPB structures.