Experimental Study on Influences of Chemical Solutions on Mechanical Properties of Brittle Limestone Under Triaxial Compression

Abstract

A series of triaxial compression tests on dry and saturated limestone (soaked in water solutions of Na2SO4 and CaCl2 at 0.1 mol / L ionic strengths with varying pH, and distilled water for 240 days) have been carried out. The corresponding complete stress-strain curves are obtained. The influences of chemical solution on rock mechanical behaviors are studied. Results from these tests indicate that: 1) Dry limestone samples have obvious brittle feature. Even if the confining pressure reaching 20MPa, the sample is still ruptured suddenly. After soaked in chemical solutions for 240 days, the deformation and failure behaviours were changed from brittle manner to more ductile. 2) Chemical corrosion is an important reason for the strength deterioration. With the same saturated time and confining pressure, the strength degradation level depends on ionic components and pH value of chemical solutions. Acidic solutions have the most significant influence on samples’ mechanical properties. The study has a good reference to researches of deep rock mechanics, and water-rock interaction.