Concrete, a combination of sand, gravel, cement, and water, is one of the most durable and sustainable building material available. Once cement and water are mixed together, the paste created will continue to harden around the sand and gravel forever.
While water is essential in creating concrete, excessive use of water can cause loss of strength, cracking, and slower set times. Think of baking a cake, if the baker adds an excessive amount of water or oil, the finished product will not turn out properly. Mixing concrete follows the same principles.
If the air temperature is too hot or too cold, special precautions need to be taken when placing concrete. For example, in extreme cold weather concrete “goes to sleep” and sets very slowly. In hot weather, the opposite happens, the heat speeds up the hardening process. In either extreme, contractors need to take the necessary precautions to ensure a quality finish to a quality product.
CARING FOR CONCRETE IN WINTER
Many homeowners experience disappointment when their new concrete pavement comes out of its first winter season with signs of scaling, which is the flaking and peeling of the concrete surface. To keep this from happening to your new concrete pavement, be sure take these precautions:
- Avoid applying de-icing chemicals to concrete less than two years old; use traction sand as a substitute for de-icing chemicals.
- Avoid using calcium or salt on your pavement, regardless of the age, and never use products containing ammonium nitrate or ammonium sulfate (fertilizer). These chemicals are often packaged and sold as de-icers, but they will rapidly disintegrate the concrete.
- After the second winter, if heavy concentrations of chloride will be used as de-icers, apply a concrete sealer in the fall for protection.
- Don’t allow snow and ice to accumulate on the slab during the first winter—keep it cleaned off!
- Hose off accumulation of salt deposited by cars on newly placed driveways and garage slabs.