Dealing with Climate and Attacks on Colored Concrete
It doesn't take long for cold weather to wreak havoc on virtually anything left outside. Interestingly, however, this is especially true of certain things such as concrete, which can be adversely affected by things like anti-ice treatments long after the snow and ice have gone for the season. In fact, according to a report released recently by the Minnesota Department of Transportation, colored concrete surfaces deteriorate faster than plain grey concrete, especially in cold weather. If that doesn't get your attention to prevent this problem in the future, nothing will.
The good news in this is that there are several ways to prevent this problem, all of which you can do something about. The factors which affect the longevity of the concrete include:
- Mix design of the concrete
- Slump of the concrete at the time of the pour
- Proper preparation of the subbase
- Working during the finishing process
- How the concrete was poured
Generally speaking, the way a concrete slab is put together should be carefully done from start to finish This should be a given but is often not, especially in cold climates. If concrete is poured in cold climates, it should not be poured until it reaches a psi of 500. Otherwise, keep it covered and protected. It should also be remember that if your concrete will be exposed to salt and de-icers, the maximum water/concrete ratio by mass should be .40 with a minimum psi strength of 4,000.
It is also important to be careful not to overwork the concrete with a steel trowel. Doing this will cause cause air entrainment at the surface to deplete, leading to possible surface issues.
Finally, the first year for any concrete presents problems since it is so new. It is only after two or three seasons that it will become more durable and more resistant to de-icers. As a result, keep the de-icers off of your concrete the first season. After that, feel free.