废弃轮胎橡胶颗粒轻质混合土强度特性试验研究

Consolidated undrained triaxial compression tests on lightweight soil mixed with rubber chips of scrap tires

废弃轮胎橡胶颗粒轻质混合土(RST轻质土)是一种由原料土、废弃轮胎橡胶颗粒、水泥和水混合而成的新型轻质填筑材料。它不仅可以减小资源浪费和环境污染,还具有轻质高强的优点,可以改善填土的工程性质。为了研究其抗剪强度特性,对不同配合比的废弃轮胎橡胶颗粒轻质混合土,进行常规三轴固结不排水剪切试验,得出了固结不排水剪破坏形态及应力应变曲线、孔压应变曲线形态。结果表明随着橡胶颗粒含量的增加,RST轻质土的应力应变曲线从软化型向硬化型过渡。试验还得出了材料配比对固结不排水剪切试验下RST轻质土的抗剪强度、抗剪强度指标及孔隙水压力系数的影响规律,并从强度机理和土体骨架结构的角度分别解释了材料配比影响抗剪强度指标和孔隙水压力系数的原因,结果表明RST轻质土的强度可以用灰土比进行线性拟合。研究成果可作为进一步研究这种新材料本构关系的依据。

Lightweight soil mixed with rubber chips of scrap tires is a kind of new geotechnical material which is composed of soil,rubber chips of scrap tires,water and cement.It can reduce waste of resources and environmental contamination,and has the characteristics of being light as well as improving strength and engineering properties of the fill.Based on the consolidated undrained triaxial compression tests,the lightweight soil mixed with rubber chips of scrap tires of different ingredient proportions is studied to analyze its shear strength properties.Then the states of failure,stress-strain curves and pore pressure-strain curves of the soil are found.The results show that with the increase of rubber chips content,the stress-strain curves of the soil changes from the softening type to the hardening one.Besides,the influencing rules of the proportion of ingredient on its shear strength,shear strength parameters and pore pressure coefficients are obtained.The reasons for the influence of proportion of ingredient on shear strength parameters and pore water pressure coefficients are also discussed respectively from the perspective of the strengh mechanism and aggregate structure of the soil.The results also show that the strength of the soil can be linearly predicted by cement content.Thus the present findings may lay a foundation for further researches on the constitutive relation properties of the soil.