Study On Mechanical Property And Durability Of Cement-soil Mixed With Salix

The rational and effective utilization of resources is the core of sustainable development.Cement-soil is made from natural soil and a certain amount of cement.This kind of material is widely used in geotechnical engineering and infrastructure construction fields.It has the advantages of low cost,convenient materials and simple construction.However,ordinary cement-soil performs poorly in terms of durability and early strength.Therefore,in this paper,salix was crushed and added into cement-soil as an admixture to explore its effect on mechanical properties and durability of cement-soil,so as to find a new way for the utilization of sandy shrubs and even waste wood to be used after flat stubble.Firstly,the salix was crushed with a grinder,and the products were classified according to the difference of shape and length.According to the classification results,the unconfined compressive strength test was carried out by designing single factor and orthogonal test scheme,and the single factor test showed that the influence of curing age on the compressive strength of cement-soil was positively correlated.When comparing the admixtures of powdery,fibrous and filamentous salix,the optimum shape is wood silk.In view of the shape of wood fiber,the orthogonal test was designed by using the method of three factors and four levels to comprehensively consider the cement content,different lengths of wood fiber and wood fiber content of three factors.According to the comprehensive test results,when the cement content is 15%and the length of wood wire is about 11.8mm and the content is 1.5%,the cement-soil has the highest compressive strength and is called as modified cement-soil.Then the stress-strain curve obtained from the test is further analyzed to compare the effects of various admixtures on the peak strain,toughness and elastic modulus in the deformation characteristics of cement-soil.A verification test was set up to verify the mechanical properties of the modified cement soil.Then,by observing the photos of the damaged specimens and combining with the corresponding stress-strain curves,the damage laws of cement and soil are discussed.Finally,the freeze-thaw resistance,dry and wet resistance and corrosion resistance of modified cement-soil are compared with that of ordinary cement-soil,and the freeze-thaw resistance and corrosion resistance of modified cement-soil are improved.Cement-soil strength within 15 wet and dry cycles did not decrease but increased.The microstructure of cement-soil was observed by sem,and the effect of admixtures on cement-soil was analyzed.