Study on the Influence of Different Aqueous Solutions on the Mechanical Properties and Microstructure of Limestone

Abstract

Abstract Uniaxial and triaxial compression tests were carried out on limestone samples immersed in distilled water and pH = 2 solution for 80 days to investigate the influences of aqueous solutions on the mechanical properties of limestone. Scanning electron microscopy and image recognition techniques were employed to analyze the morphology of limestone before and after immersion in aqueous solutions. The test results show that the peak stress and elastic modulus of the limestone specimens were reduced while the Poisson’s ratios were increased after 80 days of soaking. A series of chemical reactions take place between water and rock samples during the process of soaking. Energy-dispersive spectrometer analysis results showed that the content of calcium in the surface of the sample decreases after soaking, while the contents of aluminum, magnesium, and silicon are increased. From the image analysis results, it is demonstrated that the number and area of microscopic pores of the sample after immersion increased. The physical-chemical actions between the aqueous solutions and the samples lead to the deterioration of the mechanical properties of the rock.