Research On Mechanical Properties Of Graphene Oxide Cement Soil

Graphene oxide as one of the important derivatives of graphene,has excellent mechanical properties.As a new type of nanomaterials,how to apply graphene to civil engineering is a hot topic for researchers.Cement soil mixing pile treatment is a common method of foundation reinforcement,but the cement soil has poor crack resistance and low bending strength,which has obvious defects.Therefore,this paper considers adding graphene oxide to cement soil,and explores the influence of graphene oxide on the mechanical properties of cement soil through mechanical property test,and studies the microstructure of graphene oxide cement soil through SEM and XRD tests.The specific research contents are as follows:(1)The unconfined compressive strength test and direct shear test were carried out on the cemented soil with graphene oxide.The results show that graphene oxide can significantly improve the unconfined compressive strength and shear strength performance of cement soil.With the increase of the content of graphene oxide,the mechanical properties of graphene oxide increase at first and then decrease compared with ordinary cement soil.At the same time,the increase rate of compressive strength of graphene oxide cement soil largely depends on the proportion between the content of graphene oxide and cement;(2)Through the analysis of the damage performance test results of the cement soil,it is found that the addition of graphene oxide can obviously improve the damage characteristics of cement soil,and the damage stress threshold value of cement soil is improved;(3)Through SEM and XRD tests,it is found that the addition of graphene oxide promotes the replacement of calcium ions and sodium potassium ions in the hardening process of cement soil,and the oxygen-containing functional groups on its surface can provide sites for cement hydration and promote the formation of dense cement hydrates;on the other hand,graphene oxide improves the compactness of cement soil microstructure,In the failure process of cement soil,it is difficult for microcracks to propagate through graphene oxide nanosheets and slow down the stress concentration.These conditions promote the development of cement soil strength.