电石渣改良过湿黏土的物理力学试验研究

Experimental study on physical and mechanical properties of over-wet clayey soils stabilized by calcium carbide residues

将工业废料电石渣用于高速公路路基的过湿黏土填料改良。通过含水率、颗分、击实、无侧限抗压强度、回弹模量和干湿循环等室内试验,研究了不同掺量及龄期下,电石渣改良土的基本物理力学性质和水稳性,并与生石灰改良土进行对比。结果表明:电石渣较生石灰比表面积更大、pH更高,在相同掺量和养护条件下,电石渣改良土较生石灰改良土的物理性能改善更明显,粗颗粒含量、最大干密度和最佳含水率都更高,塑性指数更小;电石渣改良土的路用强度指标包括无侧限抗压强度、CBR、回弹模量均优于生石灰改良土。电石渣改良土的水稳定性随掺量的增加而提高,耐干湿性能明显优于生石灰改良土;养护龄期对耐久性的影响不显著。

The calcium carbide residue(CCR) is utilized to improve the over-wet clayey soils,which is used as subgrade materials in highway construction.A series of laboratory tests on moisture content,particle distribution,compaction,unconfined compression strength,modulus of resilience and wetting-drying cycle are carried out to study the mechanical properties of CCR-stabilized soils and lime-stabilized soils.The binder dosages are 4%,6%,8%,and 4%,6% for CCR and lime respectively.The results indicate that the CCR has higher specific surface area,pH and fine particle content.Accordingly,the CCR-stabilized soils have greater physical performance than the lime-stabilized soils in terms of particle size distribution,plasticity index,the maximum dry density and the optimum moisture content.Additionally,the mechanical performance of CCR-stabilized soils is greater than that of the lime-stabilized soils,including the unconfined compressive strength,CBR,modulus of resilience and water durability.