#concrete spalling

Concrete Spalling is the process of chipping or flaking of the surface of the concrete, which usually occurs due to natural or chemical reactions. Concrete Spalling results in the development of small or large pieces that break away from the surface, leaving the concrete rough and uneven. Spalling typically occurs when the concrete is exposed to moisture or extreme temperature changes, including freeze-thaw cycles, corrosion, and excessive wear and tear, causing the concrete to expand and contract. Due to repetitive cycles of expansion and contraction, the concrete gets weakened and breaks apart, leading to spalling. Therefore, it is crucial to repair and restore spalled concrete at the earliest. In this article, we will discuss some of the repair and restoration options available for concrete spalling.

Surface Patching

One of the best methods of repairing concrete spalling is by applying surface patching material. For surface patching, you just mix up some sand, a little hydrated lime, and Portland cement and trowel this onto the concrete. It is the most affordable and quick way to repair small areas. To patch the concrete, the damaged area is first cleaned and cleared with safe water and masonry cleaner. Then the surface patching is applied to the affected area, and the surface is levelled off to match the surrounding concrete surface. Though Surface Patching is very effective for the smaller areas of spalling, it is not suitable for more significant or deeper spalling damage.

2. Resurfacing

If the damage is much deeper, then resurfacing becomes the best option so that the concrete can be evenly applied. It involves applying a thin layer of concrete, effectively giving it a new surface layer. The surface is first cleaned and prepared, and a bonding agent is applied to ensure that the new layer of concrete will adhere to the old surface. After that, a fresh coating of concrete is poured and polished over the top. The look of concrete surfaces that have been harmed by spalling can be effectively restored through resurfacing, but this is not a long-term fix.

3. Overlaying

Overlaying is another option that is much similar to resurfacing. The only difference is it involves a thin layer of portland concrete which should be at least 1.5 inches to ensure proper bonding and durability. If there are no major cracks, a thin overlay of 1.5 to 2 inches (38 to 51 mm) may be sufficient to enhance its appearance or improve its performance.

4. Chemical Treatment

To tackle the corrosion issue, it is important to use epoxy-based chemicals. Epoxy is generally used for small cracks ranging from 0.02 mm to 6 mm in width. Steel bars are coated with epoxy-based chemicals to increase their corrosion resistance capacity. It can also be applied to the surface of concrete, forming a protective layer that resists abrasion and chemical damage.

5. Replacement of concrete

In extreme instances of spalling, where the damage is too serious to be fixed with surface patching, resurfacing, or overlays, replacing the concrete may be the only choice. The injured concrete surface is removed, and a fresh coating of portland concrete is then poured in its place in the process of replacing concrete. In situations where spalling has jeopardized the structural stability of the concrete, concrete replacement is a more involved and expensive option, but it is frequently required.