Dusting
The development of a fine, powdery material that easily rubs off the surface of hardened concrete. This can occur either indoors or outdoors, but is more likely to be a problem when it occurs indoors. Dusting is the result of a thin, weak layer, called laitance that is composed of water, cement, and fine particles.

The following may cause dusting:

1. Water applied during finishing
2. Exposure to rainfall during finishing
3. Spreading dry cement over the surface to accelerate finishing
4. A low cement content
5. Too wet a mix
6. Lack of proper curing
7. Carbonation during winter concreting (caused by unvented heaters)
8. Freezing of the surface
9. Dirty aggregate
   

Concrete Links

National Ready Mixed Concrete Association

Tilt-Up Concrete Association

The Portland Cement Association

American Concrete Institute

American Society of Testing Materials

Concrete.com

Effingham Area Home Builders Association