Study On Mechanical Properties And Micro-structure Of Xi’an Loess Improved By Consolid System Combined With Landscape Waste Sand

Consolid System is a new environmental curing agent specially developed for soil solidified.It can greatly improve the water resistance and mechanical properties of clay foundation by the small particles in adhesion.Therefore,it has a very considerable application prospect.At present,the research on the engineering properties of Consolid System improved soil mainly focuses on clay soil,and the mechanical property test is mainly statics part.There are few experimental studies on the mechanical properties of loess,and the mechanical properties of loess roadbed under dynamic load are not involved.Therefore,based on the mechanism of Consolid System,this paper uses Consolid System,Loess and Landscape Waste Sand(40 mesh,200 mesh,1000 mesh)as raw materials to conduct experiments.The research contents include compaction test,uniaxial compression test,dynamic triaxial test,scanning electron microscope(SEM),X-ray diffraction(XRD)and mercury injection test(MIP).The aim is to study the improvement effect of Consolid System combined with Landscape Waste Sand in different mesh on mechanical properties and its microscopic mechanism under the action of static and dynamic loads.The test results show that:(1)The addition of 200 mesh and 1000 mesh Landscape Waste Sand increase the optimum water content of the solidified soil,while the addition of 40 mesh Landscape Waste Sand decrease the optimum water content.The variation of the maximum dry density under different mesh showed a similar rule,which was positively correlated with the content of waste sand for200-mesh and 1000-mesh landscape construction,and negatively correlated with the content of waste sand for 40-mesh landscape construction.(2)Consolid system can improve the compressive strength of loess.Combined with 40 mesh and 200 mesh Landscape Waste Sand,it can further improve the compressive strength of loess,while 1000 mesh Landscape Waste Sand has no obvious same effect on the strength of loess.In addition,the Consolid System can improve the stiffness of the improved soil and reduce the plastic deformation capacity of the solidified soil.When Landscape Waste Sand is added to loess,with the increase of the waste sand mesh,the stiffness of the improved loess decreases gradually,and the plastic deformation capacity increases gradually.(3)In the dynamic strength variation relationship,40 mesh and 200 mesh Landscape Waste Sand combined with Consolid System had a positive effect on the dynamic strength,while 1000 mesh Landscape Waste Sand combined with Consolid System had no obvious synergistic effect on the dynamic strength.In terms of the dynamic shear modulus change,the combination of Consolid System and 40 mesh Landscape Waste Sand has the largest amplitude of improvement on the dynamic shear modulus,followed by 200 mesh Landscape Waste Sand,and 1000 mesh Landscape Waste Sand has no obvious effect on the dynamic shear modulus of solidified soil.(4)According to the mesoscopic test,it can be found that the improvement of the loess by the Consolid system is mainly caused by the action of zeolite.When Consolid System is combined with Landscape Waste Sand for solidified.The 40 mesh Landscape Waste Sand can improve the strength of loess mainly by participating in the arrangement of skeleton particles and improving the contact mode among the skeleton particles.The 200 mesh Landscape Waste Sand mainly forms cementing body together with the Consolid system to improve the loess strength.After 1000 mesh landscape waste sand is added,the waste sand is evenly wrapped around the soil skeleton,which weakens the friction force and cohesion between the soil skeleton,and weakens the improvement effect of the Consolid System on the loess.