Authors: Gulshama, Professor Subhashini Sharma
Abstract: This project studies in detail the harmful effects of atmospheric sulfur dioxide (SO₂) and acid rain on cement-based materials, which are widely used in construction activities such as buildings, bridges, and roads. These materials are continuously exposed to environmental conditions, especially in industrial and urban areas where pollution levels are significantly high. Among various pollutants, sulfur dioxide plays a major role in the formation of acid rain, which adversely affects the durability, strength, and overall performance of cement-based structures. The project further explains the chemical reactions involved in the formation of acid rain, where sulfur dioxide reacts with oxygen and water vapor present in the atmosphere to form sulfuric acid. This acid, when deposited on cement surfaces through rainfall, initiates a series of chemical reactions with important components of cement such as calcium hydroxide and calcium silicate compounds. These reactions lead to the formation of harmful products like gypsum and ettringite, which cause expansion, cracking, and gradual weakening of the material. In addition, this study describes the mechanism of degradation, including the penetration of acidic solutions into the pores of cement, internal stress development, and surface damage. The long-term effects include reduction in compressive strength, increased porosity, and structural instability of cement-based materials. Finally, the project also highlights various preventive measures to enhance durability, such as the use of sulfate-resistant cement, protective coatings, and control of environmental pollution. Overall, this study provides a clear understanding of the impact of acid rain on construction materials and suggests ways to improve their lifespan and performance.
