Why do some concrete floors develop dust or chalk on the surface?
This is called dusting and is caused by a weak wear layer. Often this is due to bleed water being left on the surface or troweled back on during finishing. The surface layer fails to completely cure, causing a soft surface which can flake or become dusty. It can also be caused by wind, rain, snow, excessive heat, or carbon dioxide produced from heaters or engines coming in contact with the surface.
