Spalling is one of the most common problems afflicting concrete surfaces. Yet many people still fail to understand just what spalling is--let alone how to prevent and/or treat it. If you would like to improve your knowledge about concrete construction, read on. This article will provide a useful introduction to the problem of concrete spalling.
What Spalling Is
Spalling refers to the tendency of concrete to break apart into chips or flakes. In other words, spalling is a form of surface failure. Spalling in concrete is often caused by excessive exposure to moisture, as well as the repeated cycles of freezing and thawing experienced in cold climates. The use of salt-based deicing substances tends to exacerbate the problem by encouraging the concrete to retain a greater amount of water.
Spalling is also commonly caused the corrosion of underlying reinforcing elements, especially when they are made out of steel. The build-up of corrosion increases the amount of internal pressure being exerted on the concrete above the reinforcing element, thus increasing susceptibility of the concrete to spall as the result of surface stresses.
While mainly considered a cosmetic issue, spalling can create more serious problems should it lead to underlying structural elements becoming exposed to moisture and corrosion.
How To Prevent Spalling
One of the most effective ways to prevent concrete spalling is to take precautionary measures to keep underlying steel from undergoing corrosion. Such measures may involve the application of corrosion inhibitors to the surface of the metal. Likewise, it may mean installing reinforcing materials that come pre-coated in rubber or some other impermeable substance. The use of low-permeability concrete also reduces spalling by making it more difficult for dissolved surface salt to percolate down to the vulnerable steel elements.
Spalling can also be prevented through the application of chemical sealers to the surface of the concrete. Such sealers act to prevent spalling by blocking the intrusion of water into the concrete slab. Not only does this reduce the corrosion rate, but it also prevents spalling caused by the expansion of water during periods of freezing weather.
How To Repair Spalled Concrete
No matter how well protected a concrete surface, sometimes there is just nothing that can be done to prevent spalling. In that case, it is important to repair it as soon as possible to prevent the problem from growing worse. First, if any steel reinforcing elements have been exposed, the corrosion must be removed by scrubbing with a wire brush. Then several coats of anti-rust paint should be applied.
After this, the surface should be restored through the installation of a concrete overlay. This involves preparing a mixture of cement and sand, smoothing it into the damaged area, and allowing it to dry completely. Then a sealer should be applied to prevent the problem from recurring. Contact a company like Crackerjack Mud Jacking Inc for more information.