If you have a concrete walkway on your property that has a big crack in it, you should have it repaired before someone trips. A damaged walkway is a liability hazard if someone gets hurt. A large crack that has heaved can't be filled in like smaller cracks can. Instead, you'll probably need to call a concrete contractor to make repairs so the surface is level again. Here's some information on why concrete heaves and how it can be fixed.
Why Concrete Heaving Occurs
Heaving occurs when one edge of the concrete is pushed up at a joint or crack. Tree roots are sometimes the problem when the roots get large enough to lift the slab. Other times, heaving is caused by shifting in the soil. This might happen if the soil wasn't compacted well to start with or if the soil went through a freeze and thaw cycle that caused the concrete to expand and then contract. If freezing is the cause, it's possible the concrete will fall back into place when the weather warms up. If it doesn't, then the sidewalk needs repairs.
How A Heave Is Repaired
The heaved edge of the concrete can be ground down. The contractor can use a saw or grinder and shave away the part of the slab that juts above the rest of the walkway. This may not be possible if the slab is totally lifted out of place. However, grinding is often the easiest and best option when only a couple of inches need to be removed to make the walkway level again.
Another option is to cut out part of the walkway and replace it with new concrete. This may be necessary if the soil under the walkway has shifted. With the concrete out of the way, the soil can be compacted again to prevent further problems. Then, new concrete can be poured to make repairs and return the walkway to a level position.
How To Prevent Heaving
Concrete is a durable material, but it can develop problems for various reasons. You may not be able to completely prevent heaving, especially in the case of tree roots, but you can take steps to prevent the problem by fixing cracks when they develop. When a concrete walkway develops a crack, rain can seep inside of it and make the crack worse. This happens because the rain freezes and forces the crack open or because the rain causes the soil to shift. These small cracks are easy to repair with crack filler. Even though the repairs may be visible if you do them yourself, you may at least prevent heaving that could potentially cause someone to trip and fall.
Contact a company, like Burns Brothers Concrete Construction Corporation, for more help.