MONITORING OF CORROSION IN SUBMERGED REINFORCED CONCRETE STRUCTURES USING BIOLOGICAL INDICATORS

Abstract

Corrosion of steel has severe economic impacts on industry and infrastructure. Reinforcement corrosion and subsequent loss of strength is the reason for failures in numerous reinforced concrete structures that leads to billions of dollars in losses. Thus corrosion detection is of great importance. Currently, corrosion detection in existing structures is performed using non-destructive methods, which include ultrasonics, radiography, thermography, and enhanced photographic imaging. Such methods are quick but lack details and can be unreliable. An alternative approach may be measuring conditions like pH that affect corrosion. Lowering of pH can indicate that corrosion can occur. It has also been identified that certain biological factors like bacteria play a major role in corrosion through a process called Microbial Induced Corrosion (MIC). Bacteria accumulate over metal surfaces over time forming biofilms, creating environments favorable for corrosion. This thesis attempts to study the correlation between corrosion of reinforcement steel in concrete and bacterial activities measured at the concrete surface and thereby observe the effectiveness of using bacterial activities to indirectly detect corrosion in the reinforcement steel.