When properly mixed and applied concrete is one of the strongest building blocks available. Unfortunately, all concrete is susceptible to cracking over time. Those cracks can be repaired, up to a point. However, each crack takes a toll on the overall strength of that concrete.
Today, we’re going to go over the five most common factors that lead to cracks in concrete. While you can’t guarantee that your concrete will never crack, you can mitigate the chance of that happening by avoiding these mistakes in your next DIY project.
Concrete starts wet and malleable and gains strength as it dries. However, a lot can go wrong during that drying process. If the water on the surface of freshly poured concrete dries out more quickly than the water in the rest of the concrete, the surface can crack.
The best way to avoid this is to keep the surface of your poured concrete fresh by covering it up. Most concrete contractors use a plastic or polyethylene sheet, but burlap can work as well if that’s what you have on hand. As long as the concrete surface is sealed, the water inside the mixture can dry at the same speed. Uncovered concrete will nearly always result in some surface cracks.
Settlement is another common problem that leads to cracks in concrete. When settlement occurs, the ground underneath the concrete actually shifts. That shift causes cracks in the base of the concrete.
The solution to settlement is simple, but unfortunately it is not a problem that can be retroactively solved. To avoid settlement cracks make sure you aren’t pouring concrete on the wrong time of soil. Any type of dirt that is poorly compacted (think sand) can result in settlement cracks. Do your research before deciding where you are going to pour concrete.
After concrete is poured, the excess water in the mixture evaporates off which results in dry, strong concrete. However, if that evaporation is impeded by anything cracks can occur. The truth is that it’s nearly impossible to completely control how water evaporates. That’s why placing control joints between concrete slabs is so important.
Control joints create a weak point in the concrete that guide where cracks occur. That way the cracks are straight and aesthetically pleasing, rather than crooked and difficult to repair.
Concrete is capable of withstanding all different kinds of environments. In cold environments people tend to use salt or a chemical-deicer to keep their driveways and sidewalks free of ice. Those chemicals take a toll on even the strongest concrete.
As a result of repeated exposure to salt and chemicals, concrete will crack. If you’re concerned about this, try to avoid using salt or chemicals on your concrete. Alternative materials like sand, gravel and even wood chips are great ways to get traction on icy surfaces without damaging the concrete underneath.
Oftentimes people will use steel rebar, iron rails or wire mesh to reinforce the strength of their concrete. While this is incredibly effective, it does open up the concrete to some unique problems.
The metal components of reinforced concrete can rust over time. As the rust process continues small cracks will start to develop in the surrounding concrete. Unfortunately, it’s impossible to stop the metal from rusting. You can minimize the cracks by repairing them while they’re still tiny and have not yet had the time they need to expand.
Concrete can last decades if treated properly. While cracking is normal, the frequency and intensity of those cracks can be mitigated with proper care. Take the time to maintain your concrete, and consult a professional before starting any new concrete projects at home.
To learn more, visit www.razorbackconcrete.com.