Experimental Study on Acid-Rain Corrosion Mechanism of Concrete Based on Periodic Immersion Method

In this paper, we mainly study the change of concrete quality and law of mechanical change under acid-rain environment, we adopt periodic immersion method to make statistics of concrete samples in different periods. In the process of experimental design, we need to prepare raw materials, choose the appropriate mixing scheme of concrete materials, prepare materials, make testing samples, simulate the acid-rain environment; we analyze the corrosion principle of concrete samples, in different period, sample weight measurement, compressive strength measurement and tensile strength measurement are done mainly by periodic immersion method, we need to design a clear calculation method. In the steps of experimental results and analysis, XRD and SEM are adopted to analyze the morphology of concrete specimen, in order to compare the influence of acid-rain environment on concrete samples, we set different pH of acid-rain environment (1.2, 2.5 and 4.5, respectively), we find that with the increase of soaking time, a large number of holes appear on the surface of concrete samples, at the same time, the lower the pH is, the larger the pore size of these small holes will be; we analyze the quality of concrete samples, and adjust the pH of sample, soak for 90 days respectively, every 10 days can be taken as an observation time point, we find that the quality of concrete samples shows a downward trend as a whole, at the same time, the smaller the pH is, the faster the mass declines; we test the compressive strength of concrete samples and tensile strength of concrete samples, find that with the increase of pH, the compressive strength of concrete samples and tensile strength of concrete samples show the trend of first increasing-then decreasing.