Cracked and crumbling concrete is not only unsightly they can be a symptom of other problems and may lead to property damage.
There are several different methods you can choose to repair your concrete depending on the severity of the problem, your individual skill and the cost. The professional should be able to determine the cause of the crack and use suitable method to fix it.
Before any repairs are done you need to determine the cause to prevent further damage after the repairs are completed.
1 Epoxy Injection
Epoxy injection bonds cracks as narrow as 0.002 inches and restores soundness and integrity of the concrete. This easy one-step fix method is one of the most preferred ones for smaller cracks. Most homeowners should be able to do this themselves. Cracks injected with epoxy solution need to be dormant, so make sure the cracks you are about to fix are not filled with water or other contaminates.
2-Routing and Sealing
This is also a simple and economical method to repair concrete and can be used for fine, isolated, and large cracks. It is basically a non-structural repair that enlarges the crack and fills it with a compatible joint sealant. Depending upon the shape and size of the sealant, routing and sealing method can seal both dormant and active cracks. This is considered to be a suitable method for horizontal surfaces mostly. Appropriate sealants include urethanes, silicones, epoxies, asphaltic, polyureas materials and polymer mortars.
3-Stitching and Doweling
Stitching method involves drilling small holes on both sides of the crack and using U-shaped metal staples to anchor the concrete. Doweling, is very similar as it consists of drilling small holes and anchoring straight steel dowels at about 45 degree angle.
Stitching is mostly used for slabs of any amount of thickness, but doweling tends to work only for 6-inch or thicker slabs. However, both methods restore tensile strength and integrity across the crack. You can use either rigid or flexible materials to seal the cracks and staples.
Whether you want to use stitching or doweling will be up to the plumber to decide. This is not a method the typical homeowner will be able to do.
You can have a professional gravity fill the cracks using low viscosity urethanes, epoxies and high molecular weight methacrylate. This method can be used to fill gaps with widths ranging from 0.001 to 0.080 inches. It should be remembered that lower viscosity materials could only be used to fill narrow cracks, making it an ideal method for surfaces with multiple dormant cracks. The area and the cracks should be thoroughly cleaned with air or water blasting before flooding the area with resin. In case the cracks are filled with moisture, dust or other contaminants, the repair material will not be able to penetrate deeply into the crack. The material is pushed into the cracks with the help of brooms and squeegees.
Polyurethane resins are primarily used to seal wet and leaking cracks. This method is used to stop water leaks. It consists of injecting the crack with a reactive resin that combines with water and forms an expanding gel that seals the crack. Hydrophilic resins tend to chase the water and penetrate easily into tight micro-cracks. This concrete repair option is a permanent repair regardless of the cause of the crack. Most professionals will have the proper knowledge and equipment to do this job to your satisfaction.
When done correctly you should be able to enjoy your concrete for many years to come.