Whether the damage is cosmetic or structural, concrete repair products offer contractors more options than ever. New materials can create a strong bond, provide strength, and even disguise patching and cracks.
The key to any concrete repair is identifying the cause of the damage. This involves a thorough evaluation of the structure, destructive and nondestructive testing, and chemical and petrographic analysis of concrete samples. For professional help, contact Level Ground Excavation.
Concrete repair can be a complex project. Whether it’s reforming an edge for a residential concrete step, injecting repair material into a crack in a slab or replacing an entire section of sinking, sunken concrete, the job requires a thorough evaluation of the existing condition, determination of the causes of the deficiency and selection of appropriate repairs methods and materials. This assessment includes review of available design and construction documents, a structural analysis of the structure in its current deficient condition, destructive and nondestructive testing, visual inspections, abrasion tests, and chemical and petrographic testing of concrete samples.
It is important that the contractor clearly understand what the concrete problem is and determine the cause, whether it is a lack of adequate drainage, improper construction or ground movement. Incorrect identification will lead to a substandard result or a repair that fails prematurely.
For a partial-depth repair, chipping deteriorated concrete to expose sound and clean concrete is the first step. This is done with a lightweight 15 lb electric or pneumatic chipping hammer to avoid damaging the sound concrete that will remain in place.
A scratch test is also a vital part of the assessment process. A sharp, rough surface with an angular edge is ideal for the repair material to bond with. Surface preparation should be free of any oil, grease or paint that can prevent the new repair material from adhering to the concrete.
The most common sign that concrete needs repairing is when areas begin to look uneven. This is usually due to weather conditions or bad foundation work, and it’s essential that any concrete issues are addressed early on to prevent further damage.
When it comes to larger, more serious problems, concrete experts are required. A professional will be able to advise and recommend the right solution for the problem, from filling a small crack in a driveway to raising sunken sections of concrete with a product like PolyLevel. It is a noninvasive, quick and economical way to fill voids in concrete and lift it back to its original position, because it solves the root issue by injecting a polyurethane foam that compacts the soil.
The primary concern in concrete repair is that the material and structure being repaired bond correctly to the existing substrate. This requires adequate surface preparation of the concrete before any material is applied. The surface must be free from dirt, oil, grease and other contaminants that may interfere with a strong bond. It is also important to determine any underlying problems that need to be corrected in order for the repairs to last.
Depending on the type of repair material, the concrete should be prepared to achieve a suitable surface profile. This can be done by chemical cleaning, acid etching, mechanical preparation and other methods. The profile is important as the thickness of a repair can affect certain properties such as dry shrinkage, elastic modulus and thermal coefficients. Some materials cannot be used on deep repairs as they can develop internal stresses that can cause sag and spalling.
If a liquid bonding agent is to be used, the existing concrete should be dampened and allowed to dry to a tacky condition. The bonding agent can be painted on or sprayed on if desired, but direct application is better. It is important to follow the instructions for the bonding agent, as they can vary slightly from product to product.
It is a good idea to hire a professional contractor for concrete repairs. They will have the expertise and experience to ensure that the repairs are completed properly and will last. They will also be able to advise on preventative maintenance to avoid future damage.
Some concrete contractors have access to high-quality repair materials that are not available to the general public. These materials often include polymers that provide a stronger bond with concrete and add durability to the repairs. They can also reduce the time and cost of the repair process.
It is also important to make sure that the underlying problem is addressed when making concrete repairs. For example, if the concrete is cracked because it has settled over time, then it is best to use a lifting solution like polyurethane foam injections to solve the problem and prevent it from happening again.
Filling the Crack
When it comes to concrete repair, the goal is to restore structural integrity. Using a band-aid fix such as mixing a polymer-modified cement product with water and wiping it over cracks is not an effective or long-term solution. This type of quick fix will not stop active cracks from forming, it simply masks them until new tension causes them to expand further.
A much better approach is to remove all existing material from the cracked area and then use a high-strength, rapid set concrete patching material. The patching material should be mixed and troweled into the crack and then sanded down to a smooth surface. The sanding will also help to seal the crack and prevent water and other contaminants from seeping into the concrete once it’s dry.
The next step is to clean the area around the crack. This can be done by using a pressure washer or a brush with a damp rag. This step is necessary because the surface must be free of loose dirt and other debris that could keep the patching material from adhering to the concrete. It is also important to make sure the crack is completely dry, so it can be resealed with a concrete bonding sealant.
Before filling the crack, it is a good idea to prime the concrete with a masonry cleaner. This will ensure that the repair is well-bonded to the existing concrete and will not flake off in the future. The masonry cleaner can be purchased at most home improvement stores and should be used in accordance with the manufacturer’s instructions.
Lastly, the crack should be cleaned with a power hose or brush to remove any remaining dirt, dust, or other contaminants that would prevent the patching material from adhering to concrete once it’s dried. This step is particularly important if the crack is in an exposed location.
When it comes to repairing slabs of concrete, many contractors prefer a technique called “crack stitching.” This involves drilling additional holes into the slab along the length of the crack and then using metal anchors (U-shaped bars) to bridge the crack from one end to the other. This method is more time consuming than other methods, but it is the best way to stabilize major cracks and prevent them from spreading further.
Before the concrete repair is applied, it’s important to make sure the crack is sealed. This is because it prevents moisture and other materials from seeping into the crack, causing more damage to the concrete. This also helps keep the crack from becoming a problem again in the future.
There are a number of different methods for sealing cracks in concrete. Some of these include:
This method involves injecting epoxy into the cracks, which then welds them together. This is a good option for structural repairs and can be used on active or dormant cracks. However, it isn’t suitable for cracks that are caused by movement of soil or water.
Concrete routing and sealing
This is a good choice for dormant cracks in concrete and is relatively simple. The crack is cut into a V shape and the area around the crack is cleaned to remove dirt or debris. Then, a plank is placed over the cracked area and the concrete repair material is spread evenly along the plank. This can be done with a trowel or a squeegee, depending on the type of product being used.
Concrete surface patching
This is another great choice for repairing dormant or active concrete cracks in buildings and structures. It is not recommended for structural repairs or for cracks caused by ground swell, water pressure or tree root growth. It is a very quick and easy solution to repair small surface cracks in concrete.
Sealing a concrete crack isn’t as complex as it might seem, and the benefits are many. A professional concrete contractor can help determine the best approach for a repair and guide preventative maintenance to avoid future damage. They can also provide advice on using the proper tools and materials for the job, which will ensure a long-lasting repair.