A safe Corrosion Solution for Concrete Construction
Concrete is one of the most widely used construction materials in the world due to its various advantages such as formability and durability. It serves as the foundation for much of civilization’s infrastructure and physical development. In fact, nearly twice as much concrete is used worldwide than all other building materials combined.
Concrete is a mixture of cement, sand, aggregate, and water, which is strong in compression but not in tension. This critical issue is addressed by incorporating reinforcing steel into the concrete and casting wet concrete around robust steel bars. When the concrete sets and hardens around the bars, we obtain a new composite material known as REINFORCED CONCRETE (RCC). This makes it a versatile material that works effectively in both compression and tension.
Concrete resists squeezing due to compressive strength, while steel resists bending and stretching due to tensile strength. This enhances ductility, reduces long-term deflections, or increases the flexural capacity for beams.
Corrosion of steel in concrete structures plays a significant role in affecting the service life of such structures. The corrosion of reinforcing steel can be a significant problem in concrete structures. The corrosion of steel produces hydrated iron oxide or rust, which is very detrimental and expensive. This expansion creates internal pressure, eventually leading to concrete failure in the form of spalling. This is a leading cause of concrete deterioration, and numerous studies have been performed to prevent the corrosion of reinforcing steel.
The first line of defense against reinforcement corrosion is inhibiting the penetration of water, oxygen, carbon dioxide, and salts from the concrete surface to the reinforcement. Several tests aim to assess permeability, diffusion, absorption, or other direct measures of fluid penetration resistance. The most frequently used test is ASTM C1202, commonly referred to as the Rapid Chloride Permeability Test (RCPT). The RCPT measures the electrical charge that travels between two sides of a concrete specimen during a six-hour period. This charge is correlated to chloride ions traveling through the pore system. Lower values indicate higher resistance to chloride intrusion.
