Study of Different Microbial Corrosion Mechanisms in Sewer Pipes Network Made by Sulfur Concrete with focus on Strength and Durability Analysis

Concrete corrosion has a great economic impact on many worldwide projects especially in corrosive environments such as municipal sewer systems. Many different factors can cause corrosive attacks on concrete structures that can be categorized into two main groups, chemical sulfuric acid attack, and microbial corrosive process via producing biogenic sulfuric acid (BSA). The present work aimed on assessing the sulfur concrete durability in sewerage environment and investigating the effects of microbial corrosion on this type of concrete. In this study, two tests were conducted including sewer concrete pipe in situ, and experimental tests on cubic samples. For biological tests, this bacterium was chosen for performing laboratory tests since the presence probability and population of Thiobacillus thiooxidans microorganism in domestic sewer is higher than other species. Results showed that sulfur concrete is considerably resistant to severe acid attack, but is less resistant to microbial corrosion attack than chemical corrosion especially against sulfur oxidizing bacteria. This is completely different in Sewer environment, because the microbial attack is limited by some factors such as pH variety and other bacteria presence competition.