Influence of tailings particle size,cement-sand ratio,and slurry concentration on mechanical properties of tailings backfill
In order to study the influence of tailing particle size,cement-sand ratio,and slurry concentration on the mechani-cal properties of cemented tailings backfill ( CTB),the uniaxial compression tests based on digital image related technologies were conducted to analyze the mechanical properties and strain field distribution characteristics of CTB with different particle sizes.The scanning electron microscope was used to obtain the microstructure characteristics of CTB,so as to reveal the influ-ence mechanism of tailings particle size on the mechanical properties of CTB.The results show that with the increase of tail-ings particle size,the elastic stage of stress-strain curve is prolonged,and the plastic stage is shortened.The evolution process of fracture can be divided into four stages:closure,development,expansion and penetration,and the cracking degree of CTB is smaller before the peak stress and larger after the peak stress.With the increase of tailings particle size,the surface porosity of CTB decreases,and the number of C-S-H gel increases gradually.The influence degree of multiple factors on the strength of CTB is as follows:tailings particle size and cement-sand ratio>tailings particle size and slurry concentration>slurry concentration and cement-sand ratio.The research results can provide theoretical guidance for the design of backfill pa-rameters in underground mines.
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维普
