Research On The Salt Destruction And Protection Of Sandstone Relics

In the historic stone, sandstone relics due to the reason that the composition and structure of the material itself is porous, high water absorption, and therefore more vulnerable to weathering and corrosion. The soluble salt dissolved crystal formation damage can be formed of mutual promotion and differentiation of various types of results, it will lead to vicious spiral. The sandstone belongs to the Maiji mountain grottoes, the located in an area of significant seasonal, rainy seasons and high rainfall in the rock mass of soluble salt susceptible to temperature and humidity changes caused by the repeated dissolution crystallization expansion and contraction will produce stress damage to the pore, the rock becomes loose, reduce the intensity of pulverization and peeling phenomenon, and thus more conducive to the weathering corrosion. Experimental study on the sulfate and chloride solution to soak and dry wet sandstone freeze-thaw cycle test results:(1) different soluble salts of sandstone formation damage form and the degree is different. The sulfate crystals to more significantly than that of chloride. The failure performance as the cause for sandstone surface desertification and the passivation of edges; chloride on sandstone formation of greater destructive power will lead to exfoliation of the sandstone, cracking decomposition.(2) IN different cation salts, the destructive force of sodium and potassium is significantly, while ammonium salt would uniform crystal is formed on the surface of sandstone, but on rocks to a protective effect.(3) Through the performance test of polyepoxysuccinic acid(PESA) and experimental comparison of different concentrations of polyepoxysuccinic acid and clear water, we can learn that PESA will change the salt crystal and Increase the solubility of sodium sulfate. And PESA can effectively inhibit the destructive force of sulfate crystals on sandstone.(4) By comparison,5% concentration of polyepoxysuccinic acid is better to prevent the effect of salt damage, Therefore, in the selection of this material to do the protection of research, it is recommended to choose a low concentration.