The document discusses chemical attacks on concrete structures including sulfate, chloride, and acid attacks. It summarizes research on the effects of sulfuric acid attacks on different concrete mixes. Specimens were subjected to alternate acid immersion and drying or continuous immersion. Weight loss, thickness changes, and increased sulfur content indicated physical and chemical deterioration. Test results showed conventional concrete had higher compressive and flexural strengths than concrete with added sulfur or epoxy coating, demonstrating protection against sulfuric acid attack.