Slab Scaling

[Swizzle]

21 Feb 08 16:12
I work for a ready mix concrete producer which does a good deal of business in the decorative concrete area. We use the Davis integral color system (Chameleon). I was asked by a stamping contractor to look at some pool deck concrete he poured this summer. His customer notified him early February (once the snow had melted) that there was a problem. The deck has severe scaling on about 50% of the area. Short of replacing the concrete, does anyone have any experience with polymer modified overlays? If so, can you recommend a product that works in this application?

 

[concretemasonry]

Scaling with stamped concrete is usually a result of the placement, finishing and curing. This does occur with pigmented and unpigmented concrete.

The "Chameleon" process is just a different method of using the normal iron oxide pigments. It is limited to the batching process since, the pigments are common to the industry. Liquid is just easier to dispense if you do not expose it to freezing temperatures (knowingly or unknowing) before batching.

Due to the nature of "stamped" concrete, the finishing practices are not always in agreement with accepted practices.

Since the concrete was placed in the summer, but the scaling was first observed when the snow melted, freezing is a prime candidate. Any overlayment would be placed on concrete that may have some deterioration that has not been discovered, so coating is not a reliable method.

Check for the appearance of any salts stains on the surface. They could have be from deicers or the chloride ions from high chlorine levels of the water. Also, pay attention to the form and location of the scaling to see if there is any commonality. The fact that the concrete is pigmented and many of the placement practices are based on the appearance of the concrete that changes with the apparent color of the wet concrete.