Experimental Research On Electrochemical Treatment Of Mudstone

Mudstone is the main composition of sedimentary rock in coal measures strata，and themain mineral composition includes clay minerals，detrital minerals and epigenetic minerals，and the proportion of clay mineral content can reach more than40%. Due to the presence ofclay minerals in mudstone，its physical and chemical properties are susceptible to water，humidity，temperature and pressure and other environmental factors，particularly，mudstonecould show strong swelling capacity and prone to softening disintegration when clay mineralscontact with water. In the recent years，with the rapid development of China’s economy，thepace of the construction of engineering field has accelerated，the properties of mudstone willhave a significant impact on the stability of project，and resulting in great economic losses.Therefore，to explore a method of changing the properties of physical and chemical onmudstone，which is important for improving the security and stability of soft rock engineeringin a long term.In view of these，Shandong Wali coal floor clay shale was taken as the research objectwhich is rich in clay minerals，in-depth analysis of the physical and chemical properties andthe electrical percolation mechanism under the action of DC，clay shale was modified byelectrochemical methods，and further completed the clay shale expansion test，the sheardestructive test and similar simulation test. This paper has made some achievementssummarized as follows：(1) Systematically analyzed the electric double layer model and the theory， themechanisms in the process of the electrochemical reaction， include the electrolysismechanism， electrical percolation mechanism， electric mechanism and electrophoresismechanism.(2) Remolded samples expansion test was carried out under the action of different electric potential gradients，and we concluded that electrochemical play an important role toinhibit the expansion of rock samples. The final expansion is the smallest when the electricpotential gradient is0.5V·cm-1. Therefore，the best electric potential gradient is0.5V·cm-1forthe electrochemical modification.(3) Mudstone shear destructive test was carried out，and we concluded that the averagetensile strength of remolded samples have improved after the electrochemical modification，inthe range of23.08%-50.58%. The tensile strength of the rock sample is being fought outmost obvious when the electric potential gradient is0.5V·cm-1.(4) By conducting similar simulation test，after systematic analysis we concluded that thestrength of the specimen is that the anode is greater than the cathode，the sequence of theiruniaxial compressive strength is Cu>Fe>Al. In addition，the electrical resistivity size ofspecimen can reflect the uniaxial compressive strength，and provide a simple method for thedetection of geotechnical engineering. Taking into account the size of uniaxial compressivestrength，the degree of corrosion of the electrode material and the operability and economic ofconstruction in the process of surrounding rock modification of mine roadway，it is a effectivemethod that regard stainless steel bolt as the electrode material.