Causes and Solutions For Spalling Concrete – GSG Distribution
Spalling concrete refers to concrete that has become pitted, flaked, or broken up. This could be caused by poor installation, stress, and environmental factors that damage concrete. The damage could be cosmetic, but could result in structural damage. It could damage the reinforcing bars placed inside the concrete. Therefore, it is important to attend to and repair concrete spalling issues as soon as you notice them. The signs of spalling include a rough and flaky surface and breaking of some concrete chunks. This could be repaired by removing the damaged section so that it can be filled with cement.
You can address the spalling problem immediately the concrete is poured. This is the first step you should take to stop the problem from taking place. To effectively do this, mix the concrete with some amount of water, but ensure that it is well mixed. The concrete should be kept dry because if the water content is high, it may weaken the material. Also, the concrete needs some time to cure. Ensure that you protect the concrete from elements that could necessitate for concrete spalling repair. Sealants could be used to protect and give the concrete a decorative finish.
When you notice signs of deterioration in concrete installation, you need to act fast and address the issue. If you take a lot of time before filling the cracks or the chip, pit and the flake are repaired, you run high risks of damaging the concrete. If the spalling concrete has affected the structure, it is advisable that you consult a professional so that you can be advised on what should be done. If the damage to the concrete has ruined the bars that reinforce the concrete, it becomes an urgent problem that should be sorted out immediately.
In a case of decorative concrete, spalling is a major problem since it could completely mar the concrete’s appearance. This could happen even after the damaged part has been repaired. Matching patterned concrete and tinted concrete could be difficult to repair because wear may alter how the concrete appears. If the concrete spalling appears to be decorative you may need to contact a contractor to repair the concrete.
Tips on repairing spalled concrete
You will always receive calls from customers asking you to explain why their concrete is flaking and what should be done to solve it. The spalling concrete looks like an oval depression along the joints or concrete surfaces. This problem is common in colder environment where de-icing chemicals are used. It can also be caused by the freeze-thaw cycle.
How Spall takes place and the best way to avoid it
Spalls may appear because the rebar is exposed and water has made the rebar to start rusting. One of the reasons for this could be the fact that concrete joints were not properly built. Changes in weather make the concrete to expand spall and start deteriorating. One important thing that can stop the concrete from spalling is by applying a concrete waterproofing sealant to the surface so as to stop water from infiltrating the concrete.
If you manage the concrete well and follow appropriate techniques, it could help provide sufficient concrete cover. It can help to reposition the joints and cover the rebar. One of the key factors that should be considered is the concrete mix because a high water content may actually trigger the condition. You need to pay some attention to the exposed edges concrete at the corners so that it provides adequate concrete to cover areas specified by structural engineers.
Fixing Concrete Spalling
There are a number of solutions that can be offered depending on the severity of the condition. The solution to this may require that less labor intensive repairs be done. Here are some of the ideas you could use to fix the spalled concrete.
- Once you notice a damaged concrete, if it is less than 1/3 of its thickness, the repair could be done. However, when it is deeper you may install steel bar and may require a full restoration.
- If the rebar is exposed or corroded, it should be cleaned before it is restored. Use a wire brush to clean the steel bar well before you apply a protective coating. It could help to stop or prevent this.
- When the problem is on the horizontal surface or over the driveway such as sidewalks, or plaza, you may need to apply a cement overlay. Once the overlay set is completed, a waterproofing membrane could be applied to stop and prevent concrete spalling.
- To carry out a successful repair, ensure that you remove the concrete about 1.5 inches deep. You should then clean and remove the debris before the repair commences.
- You can do patching so that it extends 4’’ beyond the area affected by concrete spalling.
- If you want to get better results, cut the rectangular part of the concrete so that the patching could be done and get the concrete contained within the specified area.
- Remove and clean the debris and ensure that the all particles are removed. It could be cleaned with water but the excess water should be removed using a sponge. The surface should dry up before the compound is applied.
- The old surface should be rough so as to allow for better bonding within the new concrete.
- The best patching materials include epoxy and Portland cement.
- Patch material should be mixed well but you should consider that they can react or mix with what you want to use within 15 minutes.
- Ensure that the air temperature is above 40 degrees Fahrenheit if you want the patching to work well.
- Ensure that you only use materials that have similar expansion coefficient with that of the existing concrete.
- Before the joint is repaired, ensure that it is restored properly so as to give some allowance for expansion of the slab.
Other options available
Other than the rust inhibitor which needs to be applied over the rusted steel rebar, you need to buy good products, which can be applied on the aforementioned rebar, and which can be used to repair spalled concrete. Consider buying concrete products from GSG Distribution for spalling concrete foundation repair.