Not all concrete is made the same, in fact most concrete differs slightly even batch to batch. This fact often comes as a surprise to the over DIYer but, the truth is it makes concrete even more versatile. One of the more obscure types of concrete is called air-entrained concrete.
Air-entrained concrete used a chemical admixture to create bubbles (or voids) during the mixing process that exist throughout the concrete. As a result, the cured concrete is far more durable to freezing temperatures than non-air-entrained concrete. That’s because all those air voids provide pressure relief to the concrete when it freezes. Without those voids, the pressure would build until it was relieved through cracking.
Air-entrained concrete is also more durable against chemical buildup from different treatments. For example, if you live in an area that experiences snow and ice an air-entrained concrete would be able to better hold up against salt or anti-icing treatments.
It is important to point out that air-entrained concrete has to be treated differently than normal concrete. The most important example of this is hard troweling. Hard troweling refers to the process of using a steel trowel as a finisher on concrete before it’s dried. The process results in a smooth hard surface. Depending on how many times the process is repeated, the concrete can end up with a burnished, mirror-like appearance.
However, hard troweling can’t be done to air-entrained concrete. That’s because of something called densification. Desensification is the process of air being pushed out to the surface of the concrete. When that happens, the air voids that were created during the air-entrained are ruptured. That creates a large space just below the surface of the concrete that will eventually lead to weakened concrete and aesthetic defects.
The fact of the matter is that air-entrained concrete is only really useful to people who live in cold environments. If you do find yourself living in an area that experiences winter, you should seriously consider using air-entrained concrete for your outdoor projects.
Of course, it’s always worth consulting with a professional. To learn more, reach out to Razorback Concrete at www.razorbackconcrete.com.