Why Does Concrete Crack?
Cracks in your concrete can be an unsightly blemish to your otherwise pristine driveway or sidewalk. Usually the first reaction most of us have is “how did this happen?!”. Cracks in concrete can form for a variety of reasons; climate, nature and human error can all be contributing factors.
Reasons Concrete Cracks
Excess Water
Concrete actually requires minimal water to properly form. However this low water mixture makes the material harder to install and finish. Some contractors will increase the amount of water in the mixture to make the material easier to work with. The excessive amount of water added to the mixture creates an inferior bond and weakens the overall strength of the pour. When concrete cures, the excess moisture evaporates and the pour begins to shrink and harden. The more water that evaporates, the more the slab will shrink resulting in the slab actually pulling itself apart, causing cracks. These types of cracks can be avoided by using a reputable concrete contractor that uses the appropriate mix for the job at hand.
Drying too Fast
A concrete slab is the result of a chemical reaction. Moisture is added to aggregate and bonding agents, as moisture evaporates the slab cures and hardens leaving a solid, durable surface. On especially hot days where the sun is beaming down on a fresh concrete pour, water can evaporate too quickly. Concrete takes time to properly set but if the mixture is too dry on hot days the slab can become brittle, resulting in a structurally unsound slab that can develop cracks.
Absence of Control Joints
For larger slabs of concrete cracks may be inevitable. However, most reputable contractors will use control joints that allow the slab to crack along a specific designated line. If a slab is too large and and control joints are not implemented, then the natural upheaval and shifting of the slab will cause cracks to form to relieve the stress and weight. Contractors should assess the size, thickness of the slab, and weight to determine where and if relief cuts are necessary
Weather
A concrete contractor can do everything perfectly and yet mother nature can still find a way to appear. Here in WNY the natural freeze/thaw cycle of the seasons can cause the upheaval in the earth beneath the slab causing the slab to rise and fall with the seasons. In most of these cases, it’s a victim of location and while a contractor can do their best to prepare for the future, sometimes fighting nature is an unwinnable battle.
Nature
Here in WNY we are blessed with plenty of foliage. Around fall the leaves change color and we are lucky to be able to drive down most streets and admire all the different colors of the trees. If you’ve ever walked down most of the sidewalks, you’ll soon realize that trees can cause their own issues. Trees, or more specifically their root systems, are an unrelenting force that grow wherever it wants, raising and cracking concrete where it pleases. In these cases, removing the cause of the problem (the tree root) is usually the only course of action to resolve the issue.
Got Uneven Concrete?
Has cracked concrete caused uneven slabs that could be a potential tripping hazard? Bravo Concrete Maintenance specializes in concrete sealing and leveling to rejuvenate your concrete and restore it to its initial charm. Call us today at (716) 834-2454 for your next project estimate!