Corrosion of reinforced concrete is a major challenge for the construction industry. It is a natural process that occurs when the iron rod, which is used to reinforce concrete, is exposed to oxygen and the presence of water, which create a red iron oxide referred to as ‘rust’.
Electrons migrate from the anodic zone to the cathodic zone, releasing ferrous ions at the anode and hydroxide ions at the cathode. This leads to a potential difference between the anodic and cathodic areas at the surface of the steel reinforcement.
This results in the creation of rust. Rust causes the surrounding concrete to crack and become damaged. These cracks then make their way to the surface of the concrete which causes even more CO2 and chloride to penetrate the concrete and speed up the process of corrosion.
Effects of Corrosion on Buildings and Structures
Corrosion has direct effects on reinforced concrete structures. It weakens the structure; reduces the bonding strength of the materials, limits the ductility, and reduces the shear capacity of the buildings.
- Weakness of structures
- Reduced bonding strength
- It causes fatigue
- Reduced ductility
- Reduced shear capacity
When corrosion occurs, the entire structure loses its strength and becomes very weak to the loads it was originally built to carry. It starts by reducing the effectiveness of each structural components, which in turn reduces the axial, and flexural strength of each element and makes it structurally weak.
Corrosion affects the iron rods which provide strength to the concrete by eating and smoothing their grooves and cross-section. As a result of this, the bond strength is often compromised. This leads to slippage of the concrete and eventual collapse of the building or structure.
Another effect of corrosion on buildings and structure is that it causes fatigue to the strength of connections, steel, and reinforced concrete elements. Corrosion usually hastens the crack of structural steel.
Corrosion is capable of significantly reducing the ductility of the overall structure, exposing it to crumbling under stress. Corroded sections of a building have lower ductility which have their response to earthquake and other natural disasters.
Corrosion reduces shear capacity in beams and columns, concrete slabs and footings. This reduces the shear strength of the slabs close to the columns and increases the possibility of shear failure. Also in footings, corrosion can result in shear failure of the footing, anchorage failure, or flexural yielding of steel reinforcement.
How to Prevent Corrosion of Buildings and Structures
One of the ways to prevent corrosion of buildings is to use corrosion-resistant Thermo-Mechanically-Treated (TMT) iron rods. The manufacturing process of TMT iron rods gives them enhanced rust and corrosion resistance. This is one of the reasons they are better than local iron rods which lack this quality.
Use TIGER TMT iron rods for all construction types
TIGER TMT iron rods, the best TMT brand in Nigeria, have greater corrosion resistance. The anti-corrosion properties of TIGER TMT iron rods is enabled by the automated labs and the most modern testing equipment which are used to test the micro-structure. This gives every rod produced perfect chemistry and the right carbon content which make it to withstand rust and corrosion.
By resisting corrosion, TIGER TMT iron rods are able to bear huge load of a complete structure and protect it from spalling and cracking.