Study On Creep And Microstructure Of Corroded Sandstone

The hydrochemical factors in the rock mass environment are continuously int eracting with each other by physical,chemical and mechanical methods.However,t here are many inherent defects in the rocks generated by geological processes.Un der Water-rock interaction,the rock surface characteristics will change,the internal d efects of the rock are enlarged,the microstructure will change and the mechanical properties of rock are gradually affected.In this paper,based on rock creep theory and electrochemical impedance spect rum theory,rock corrosion test and creep test of corroded sandstone are carried o ut.In addition,electrochemical tests are used to describe corrosion sandstone micros tructure in different hydrochemical environments.The purpose of all the experiment s are to study the microstructural changes?the instantaneous mechanical characteri stics and the creep of corroded sandstone,to speculation its long-term strength.The main conclusions are as follows:(1)The microstructure of sandstone has change d by the interaction of water and rock,which mainly shows that the resistance of the solution _sR decreases with the increase of corrosion time and the hydrochemi cal solution's level of the acid alkala,the double layer capacitance CPE-T increase s.Therefore,the electrochemical impedance spectroscopy is suitable for characterizin g the microstructure of rock.(2)Through the analysis of uniaxial compression test and uniaxial creep test of corroded sandstone,the results show that the uniaxial compressive strength,elastic modulusand long-term strength of sandstone samples reduce under hydration,in addition,the creep deformation increases.(3)Testing the strain trend of corroded sandstone by electrochemical method,at the early sta ge of each stress loading,the microcracks of corroded sandstone develops rapidly.Besides,the sample's creep strain has some relationship with the solution resista nce and double layer capacitance.And it provides a reference for the characterizat ion of creep strain of corroded sandstone by electrochemical impedance spectrosco py.About the conclusion of this article,they are useful for studing the influence of water-rock interaction on the physical and mechanical properties of rock.Moreo ver,they it can be used for reference in the detection of rock microstructure.