Simulated Acid Rain and its Possible Impacts on Grout

Abstract

The urban environment, due to its characteristics of population concentration, causes changes in the original environment. These changes, when studying the degradation of buildings, especially of concrete structures, include the occurrence of acid rain, deposition of solid particles and the release of carbon dioxide into the atmosphere, responsible for the carbonation of concrete and consequent corrosion of the reinforcement. Given these facts, the Boa Vista neighborhood, located in the Metropolitan Region of Recife, Brazil, can be considered an urban environment conducive to the generation of acid rain due to its high flow of vehicles, in addition to having large buildings, around 1500 housing units. . This study aimed to analyze the quality of rainwater in the neighborhood and to compare the content of existing compounds in runoff waters, with the rate of ions dragged from grout specimens, exposed to laboratory simulation of a rain intense in a natural way. Based on physical chemical analyzes carried out, the average pH found for the rains collected from the atmosphere was 6.10, indicating a slight acidity. The ions found in the highest concentration were Cland Ca +2. In addition to the content of ions incorporated by the building's water flow, it was about six times smaller than the residual material integrated in the water that came into contact with the simulated specimens, when comparing the data obtained for the pH range found in water drained from the building in a natural way (pH = 5.5 - 6.0).