We’ve discussed concrete and PSI but what is curing?
The chemical reaction between water and cement is called hydration. If the water evaporates to quickly like when it is extremely hot or freezes (we can only wish for that cool weather right now) during the first seven days of curing, the concrete will be substandard. This is why weather plays a big role in concrete work. Another factor which can pull the water out of the cement is the ground itself. Much of the DFW area ground is currently dry and cracked. This dry clay will pull all the moisture from the cement and cause a quick cure and seriously degrade the over all concrete structure and strength.
Great, we are in 100 degrees for the unforeseen future so what can we do?
Let’s start with ground work. Prior to the pour the ground should be watered and moist, not ponding or puddled but also no cracks and over dry areas. If tile allows watering should be done a day or two in advance and also the morning of the pour.
Once the pour is complete a simple method to keep everything moist is called ponding.
A simple bead of caulk around the perimeter will allow water to be held on top of the concrete. The concrete will still cure and maintain its moisture. Monitoring and maintaining also will show if there are any type of cracks or leaks in the concrete
One method that has been discussed in some areas that is not always recommend it is to put a sprinkler on the concrete. There’s nothing wrong with that if the sprinklers run continuously, what should be avoided is getting it wet and letting it dry, getting it wet and letting it dry. This will not be effective.
A polyurethane she could also be applied over the wet concrete it is very difficult though to get all the air pockets out of the concrete which will cause curing faster in certain areas and also degrade the concretes overall strength. If this method is used, make sure all of the air pockets are taken out.
Chemical curing can also be done. A simple hand pump applicator can be used to evenly spray the chemical curing compound over the surface. It is important to spray the pad horizontally to cover the concrete and then go back and spray vertically too ensure 100% coverage. A note on possibly glueing or painting after using curing compounds. It will not adhere. Pressure wash the curing compound prior to trying to use any type of paints or adhesives.
Last and most least used method for the Texas area would be curing in cold climates when the temperatures fall in the below freezing area. Wanting blankets and accelerators can be added to the mix. Any concrete plant or supplier would gladly make suggestions if that was the case.
Dave Flaishans
Project Manager
DC&H Construction
469-474-9555
