Whether it's your driveway, a sidewalk, or the patio, cracks on concrete slabs may at first just seem like an annoying aesthetic issue. Unfortunately, they can affect much more than just the look of the concrete if the cracks are ignored.
Concrete Crack Basics
On an existing concrete paved area, cracks will generally form on the surface first. Given time, they will slowly extend — both deeper toward the base as well as out toward the opposite edge of the paving. Impact, ground settling, aging and weathering, and soil pressure are the most likely causes of cracks on existing concrete.
Cracks that form soon after the concrete is installed, on the other hand, will often begin below the surface first. These cracks are caused by installation issues, such as an improperly constructed base or weak concrete mix. Crazing is another type of cracking from a weak concrete mix. It usually appears only on the surface as a network of fine cracks. Unlike other crack issues, crazing isn't a problem except from an aesthetic point of view.
Associated Issues
The main associated issue for cracks is base failure. Eventually, all cracks will reach down to the base. Once water begins to seep into the base material from above, the base will lose structural integrity and the concrete slab will fail completely. Either it will crumble or more severe cracking (often with uplift issues) will occur.
Cracks will also begin to widen over time. If moisture seeps in and freezes, a small crack can quickly become a gaping chasm, or worse, a pothole may begin to form. The concrete will begin to crumble and degrade. It is nearly impossible to effectively repair crumbling concrete, especially if the damage penetrates to the base, so the only option will be the demolition and installation of a new concrete pad.
Repair Options
Fortunately, there are repair options. For issues that occur soon after installation, your concrete service should be able to repair or replace the work under their warranty. Base and concrete mix issues usually require a full replacement. Crazing is the exception, as it is only surface deep. A thick epoxy coating or resurfacing with a thin layer of fresh concrete can camouflage and repair crazing.
Other cracks may require more detailed work. As long as they don't penetrate the base, the crack can be cleaned out and patched with a concrete epoxy. Your concrete service may also install expansion joints to minimize the chances of future cracking. An epoxy coating or resurfacing will then cover up the patchwork so the surface is attractive.
Contact a concrete service in your area if you need more help with cracking concrete.
