Abstract: Aiming at the problem of low-cost backfilling utilization for resource-oriented solid waste materials,this study takes multi-component solid wastes such as desulfurized gypsum,steel slag,and slag as the research objects,and conducts re search on the mix ratio optimization of component ratios of multi-component full-solid-waste-based cementitious materials. Based on the mixture design theory,16 groups of mix ratio schemes were designed to prepare multi-component solid-waste based cemented tailings backfill with 7-day and 28-day curing ages.Through dynamic and static mechanical tests,the mechani cal response laws and the optimal mix ratios meeting the dynamic and static strength requirements were explored.The results show that:① The dynamic and static compressive strengths of the backfill exhibit a significant positive correlation.Under the same mix ratio,the dynamic strength is higher than the static strength,and the dynamic and static strengths of the backfill at the 28-day curing age are generally higher than those at the 7-day curing age.② The strength prediction models constructed based on the response surface methodology have good accuracy.Combined with the factor analysis of multi-component solid wastes,it is found that within the material mix ratio range adopted in this experiment,slag content dominates the backfill strength under static load,while desulfurized gypsum content has the most significant impact on the strength under dynamic load.③ When the cement-sand ratio and slurry concentration are fixed,the backfill strength is determined by the synergistic effect of the multi-component solid wastes;the multi-component full-solid-waste-based cemented tailings backfill achieves high strength under the balanced mix ratio of low-to-medium content of desulfurized gypsum + moderate content of steel slag + high content of slag.The research results can provide theoretical guidance for the mix ratio design of solid waste-based cementitious materials.

Key words: solid waste materials,mixture design theory,cemented backfill,dynamic and static strength,optimal mix ratio