The best way to control cracks though is to make sure the installers install 'Control Joints'. Control Joints is a groove cut into the concrete at a specific location and the purpose of it is for the concrete to crack in that joint, so it wont be visible on the surface. The secret to fixing wide concrete cracks is to undercut the sides of the crack to give it an inverted 'V' shape. This helps the repair material to 'key' into the crack, creating a mechanical bond in addition to the chemical bond between the patch material and the concrete. Methods to avoid concrete cracking. Sometimes the underlying causes of concrete cracks are unavoidable, such as extreme weather, or the movement and settlement of earth over time. But measures can be taken at the installation stage to better allow for these possibilities, helping to mitigate the risk of concrete cracking. If reinforced concrete is to be used, cracks can best be controlled by using a large number of small reinforcing bars and by increasing the reinforcement. Mix materials that are known to have a good service record should be used.
- How To Prevent Concrete Cracking
- How To Keep New Concrete From Cracking
- How Do You Keep Concrete From Cracking
- How To Keep Fresh Concrete From Cracking
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Over time, your concrete is susceptible to cracking. Here's what you can do to prevent it and protect the look of your sidewalk or driveway.
It's very common for concrete to develop cracks, scaling, crazing and pitting. All concrete has the tendency to crack, and it's not possible to produce completely crack-free concrete.
How To Prevent Concrete Cracking
Concrete expands and shrinks with changes in moisture and temperature. The overall tendency is to shrink, and this can cause cracking at an early age of the concrete. Irregular cracks are unsightly and difficult to maintain but generally don't affect the integrity of concrete.
Control joints in concrete driveways or slabs are simply pre-planned cracks. Control joints create a weak place, so that when concrete shrinks, it will crack in the control joint instead of randomly across the slab.
The American Concrete Institute addresses this issue: “Even with the best floor designs and proper construction, it is unrealistic to expect crack-free and curl-free floors. Consequently, every owner should be advised by both the designer and contractor that it is normal to expect some amount of cracking and curling on every project, and that such an occurrence does not necessarily reflect adversely on either the adequacy of the floor’s design or the quality of its construction.”
How To Keep New Concrete From Cracking
The most popular explanation for the concrete cracking is the freeze-thaw cycle in the winter.
It's recommended to use sand on all concrete instead of salt. Salt will facilitate the freeze and thaw cycles that will then create the problem with pitting and cracking. When the temperature reaches 18 degrees, the concrete will freeze. At 35 degrees, it will melt and cause the cracking, pitting, crazing and scaling.
Concrete also cracks in the extreme sun, as it heats the concrete and causes it to expand. At the end of the day, the concrete contracts and regresses to its original, unbaked position.
A homeowner can help prevent cracking, scaling, crazing and pitting by yearly applying a good acrylic silicone solvent-based sealer to their concrete. A concrete contractor can also repair cracks with an epoxy injection, dry packing or routing and sealing techniques to stabilize the cracks.
Editor's note: This is an updated version of an article originally published on Aug. 5, 2011.
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Mr. Concrete of Indiana, Inc. has provided specialized concrete, aggregates and related solutions to the communities of Indiana in both residential and business environments for more than 35 years.
How Do You Keep Concrete From Cracking
As of July 27, 2015, this service provider was highly rated on Angie’s List. Ratings are subject to change based on consumer feedback, so check AngiesList.com for the most up-to-date reviews. The views expressed by this author do not necessarily reflect those of Angie’s List.