Experimental Research On Progressive And Deteriorative Characteristics Of Sandstone And Mortar Materials Subjected To Hydrochloric Acid Corrosion

Experimental research on calcareous cementitious feldspathic sandstone and mortar subjected to hydrochloric acid corrosion are conducted in this paper. The progressive and deteriorative characteristics of the specimens in different acid solutions is investigated durring the corrosion process. A corrosion model for this sandstone and mortar is established and the variation regularity of mechanical properties is revealed. Predicting model and approach of service life on mass rock and concrete construct are proposed taking alternation of the concentration of hydrion and calcium for main influencing factor. The main achievements are as follows:1.The character of chemical reaction stage is found by means of inspecting the change of the concentration of hydrion and calcium and the understanding for corrosion mechanism of the mortar specimen. The weight ratio and wave velocity ratio are defined and validated. The relationship of equivalent body between porosity and longitudinal wave velocity is opened out based on the thought of Wyllie's model. the essential characteristic can be abstracted as porosity-enlarged and bearing area-reduced in terms of observations of failure cross section about broken corroded mortar specimens. The simplified model is proposed and relation between the flexible strength and immersed time is derived. The calculated results and tested results are found to be in good consistency.2.The mechanical properties of calcareous cementitious feldspathic sandstone specimens immersed in hydrochloric solutions of different concentration at different stages including strength behavior, failure mode, stress and strain relation, and the secant modulus at the yielding point are described and summarized. A constant and inconstant coefficient diffusion-controlling equation of cylindrical rock specimens is deduced. The physicochemical variation regularity of sandstone is obtained by means of x-ray scanning of nondestructive detecting and chemical reaction equation. The meso-scale damage mechanism of sandstone is analyzed quantitatively, and the function relationship including the depth of corrosion, uniaxial compressive strength, density and CT numbers of rock specimens is established.3.Base on research on accelerated corroded test and understanding for diffusion regularity, thedistribution function of the concentration of mass rock and concrete materials is obtained in consideration of chemical reaction effect. 2-D seepage and diffusion FEM calculation program is developed to prediction of service life of rock slope of dam abutment in acid rain region, and deteriorative regularity of the strength is put forward.