STUDY ON CHEMICAL AND MECHANICAL DAMAGE EVOLUTION MECHANISM OF BEDDED LIMESTONE IN ACID CORROSION
This paper studies the influence of acidic water on the corrosion-mechanical properties of carbonate rocks.Limestone samples with different dip angles were immersed and dissolved in acid solution at a fixed flow rate and normal temperature at pH=3,4,and 5,respectively.The dissolved samples were subjected to uniaxial com-pression,acoustic emission(AE),and scanning electron microscope(SEM)tests.The changes in indicators such as mass,wave velocity,Ca2+/Mg2+ concentration,peak strength,elastic modulus,and AE ringing counts before and after acid erosion were obtained.The chemical and mechanical damage were characterized by changes in wave ve-locity and AE cumulative ringing count,and the full deformation process and chemical-mechanical damage evolu-tion equation were established.The results show that acidity of the solution is proportional to the degree of dissolu-tion of the rock sample,inversely proportional to the macroscopic mechanical strength,and the influence of dip an-gle on dissolution is 90°＞0°＞45°.In the acidic environment,the internal crystals of tuffs are dissolved,the mineral connections are weakened,thus causing changes in macro-mechanical parameters.The results can provide a refer-ence for the evaluation of rock stability in abandoned mines.
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