22/01/2025
This is called Concrete Spalling.
Concrete spalling can be caused by a number of factors, including:
Corrosion of reinforcement
Chemical exposure
Alkali-silica reaction
Poor quality concrete
Carbonation
Fire exposure
Inadequate depth of cover
How to Treat Concrete Spalling
Concrete spalling, characterized by the flaking or breaking off of surface layers of concrete, is a common problem caused by factors such as corrosion of reinforcing steel, freeze-thaw cycles, poor concrete mix, or insufficient cover over reinforcing bars. Proper treatment is essential to restore the structural integrity and aesthetics of the affected concrete. Below are steps to effectively treat concrete spalling:
1. Assessment
Inspection: Identify the extent and severity of spalling. Check for underlying issues such as rusted reinforcement or poor drainage.
Testing: Perform tests to assess the structural soundness of the concrete and the extent of corrosion in the reinforcement.
2. Preparation
Surface Cleaning: Remove loose or delaminated concrete using tools like hammers, chisels, or high-pressure water jets.
Rust Removal: Clean exposed reinforcing steel with wire brushes or sandblasting to remove rust and prevent further corrosion.
3. Repair Materials Selection
Repair Mortar: Choose a suitable repair mortar or concrete mix that is compatible with the existing structure in terms of strength, shrinkage, and thermal expansion.
Bonding Agent: Apply a bonding agent to ensure proper adhesion between the old and new concrete.
4. Application
Reinforcement Protection: Apply a corrosion inhibitor or protective coating to the cleaned reinforcement to prevent future rusting.
Concrete Application: Apply the repair mortar in layers, ensuring each layer is compacted and free of voids. For deeper spalls, use multiple layers to build up to the original surface level.
