锂渣对水泥复合土力学性能的影响

Effect of lithium slag on mechanical properties of cement composite soil

随着锂盐行业的迅猛发展,锂渣的堆积量也日益增加,有效利用率低,为了寻求锂渣综合利用的办法,将锂渣作为掺合料对水泥复合土进行无侧限抗压强度和三轴压缩试验,分析锂渣掺量对水泥复合土无侧限抗压强度、应力-应变关系、抗剪强度、黏聚力和内摩擦角的影响,并通过SEM试验分析锂渣对水泥复合土力学性能的作用机理.结果表明:锂渣的最佳掺量为12%时,相较于锂渣掺量0的无侧限抗压强度提高了85.1%,锂渣水泥复合土的应力-应变关系呈软化型;在一定范围内,随着锂渣掺量的增加其脆性越明显,抗剪强度、黏聚力及内摩擦角与锂渣掺量呈正比例增加;随着围压的增加其延性越明显;SEM试验结果表明锂渣能够改善水泥复合土的内部结构,增强其致密性.试验结果为锂渣在水泥复合土设计施工方面提供一定的技术参数和理论参考.

With the rapid development of the lithium salt industry,the accumulation of lithium slag was also increasing.In order to promote the comprehensive utilization method of lithium slag,lithium slag was used as an admixture on the cement composite soil without side limit compressive strength and three-axis compression test.Lithium slag dosage on the cement composite soil compressive strength,stress-strain,shear strength,cohesion and internal friction angle of cement composite soil were analyzed.Moreover,the mechanism of action of lithium slag on the mechanical properties of cement composite soil was analyzed by using the SEM method.The results show that when the amount of lithium slag is 12%,the unconfined compressive strength of cement composite soil is increased by 85.1%compared with 0%of lithium slag.The stress-strain relationship curve of lithium slag cement composite soil shows a softening type.The brittleness becomes more apparent with the increase amount of lithium slag and the shear strength,cohesion and internal friction angle increase in direct proportion to the amount of lithium slag doped within a certain range.With the increase of confining pressure,its ducti-lity becomes more obvious.The SEM test results show that lithium slag can improve the internal structure of cement composite soil and enhance its compactness.The experimental results provide certain technical parameters and theoretical references for the design and construction of lithium slag in cement composite soil.