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Applying A Thin Bonded Concrete Overlay

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individual repairs, consider using a thin-bonded concrete overlay. Fig -26: Popouts, Scaling and Spalling.
2.11 SCALING
Scaling is the general loss of surface mortar exposed to freezing and thawing. The aggregate is usually clearly exposed and often stands out from the concrete.
2.11.1 Causes
1.Scaling is primarily a physical action caused by hydraulic pressure from water freezing within the concrete and not usually caused by chemical corrosive action.
2. When pressure exceeds the tensile strength of concrete, scaling can result if entrained-air voids are not present to act as internal pressure relief valves.
3. Scaling is also caused due to the use of deicing solutions. Fig -27: Scaling of Concrete Surface
2.11.2 Remedies
Begin by thoroughly removing any loose material to create a relatively smooth surface. Contact the repair material manufacturer for guidance. Most manufacturers suggest surface preparation should include repairing shallow delaminations, surface, scaling, and aggregate popouts. This may require grinding the resulting rough surface. The committee recommends trying to achieve a concrete surface profile in the range of 3 to 5 as described in the International Concrete Repairs Institute 's Document 03732.
This is often the best range for applying most liquid-applied membranes and most thin coatings. Most liquid-applied products are not intended to level off or hide imperfections, although trowel-grade materials can sometimes be used for this purpose.

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