Reasons Behind Concrete Cracks and Effective Sealing Methods
After concrete has been poured and dried, cracks may develop. The most common reason cracks may appear in concrete has to do with shrinkage. Although concrete is poured in a plastic state, its volume decreases as it dries, causing it to shrink once it sets and hardens. Here are 3 reasons why concrete cracks and why sealing is an effective solution.
1. Effect of Moisture
If there is too much water used when mixing the concrete, the likelihood of cracking increases. Concrete containing excess moisture begins to shrink once this excess water evaporates, leading to cracking. Pay attention that you are using the proper concrete mix for your desired purpose.
2. Faulty Sub-grade Preparation
New concrete requires proper sub-grade preparation in order to provide the perfect base. Ensure that the sub-grade is free from frost, has proper drainage, and is uniform and smooth. Concrete will quickly settle and crack without proper sub-grade preparation. Concrete shrinkage is greatly reduced when a smooth sub-grade is in place, helping reduce the amount of restraint that causes cracking.
Map cracking occurs if the concrete loses too much moisture from its surface too quickly, making proper curing, the act of helping maintain concrete moisture, a critical step. Although map cracking doesn’t affect concrete’s structural integrity, it poses a serious cosmetic issue. Lack of proper curing can also cause more severe cracks requiring repair. Proper curing not only improves the concrete’s structural integrity but also minimizes the risk of surface defects, including scaling.
Why Fill and Seal Joints
Sealing the joints helps prevent surface water infiltration that causes failure of the sub-grade surface, leading to spalling. Be certain, however, to delay applying sealant until all concrete shrinkage is finished. Choose sealant materials from a reliable expansion joint repair supplier that have several important qualities. Sealants should be impermeable, bond securely to the concrete, and easily handle expansion and contraction.
Recommended Concrete Crack Repair Products
- POLYFLEX has proven effective at preventing wheeled traffic and stress vibration damage in concrete. It is a 100% solid, two component epoxy formula insensitive to moisture. POLYFLEX is an excellent choice for use in expansion joints and narrow masonry grooves. It is flexible and self-leveling, securely adhering to concrete, and serves to reinforce joints to prevent edge deterioration. POLYFLEX is also valuable as a sealant for saw cut control joints, grooves and masonry joints, preventing the build-up of dirt and protecting against the invasion of water and corrosive materials.
- KWIK-FLEX is another high quality proven concrete crack repair product. Its unique formulation is designed for quick setting, ideal for areas having low temperatures. It provides a resilient, long-lasting, high strength cure and sealant within 60 minutes. Contractors also like KWIK-FLEX because it needs no propane torches or heat lamps even when temperatures are low, staying serviceable up to -60°F. This product is also ideal as a crack filler or for use in slip joints.
Call Capital Industries at 631-298-6300 to speak our experienced concrete expansion joint and crack filler support team. We will help you select the right product for your application.