Scaling, as defined by the American Concrete Institute (ACI) Committee 116, is the “local flaking or peeling away of the near-surface portion of hardened concrete or mortar.” Sometimes called mortar flaking when it occurs just over the aggregates near the surface, it is primarily a physical action created by hydraulic pressures from repeated freeze-thaw cycles within the concrete. The expansive forces caused by the formation of ice are exacerbated with deicing chemicals, which increase both the saturation of the concrete and the number of freeze-thaw cycles. The distress mechanisms of scaling are complex on both a microscopic and macroscopic level.
Michigan is in a severe exposure climate where exterior concrete is subjected to continuous moisture, cycles of freezing and thawing, and use of deicing chemicals. Therefore, exterior concrete must be proportioned with durable ingredients designed for the climate with an entrained air-void system using proper placement, finishing, curing and protection to resist hydraulic pressures (stresses) that can promote scaling.
The most common causes of scaling are related to one or a combination of the following factors:
To read more about preventing and minimizing scaling and repair or treatment of scaled concrete surfaces download our full bulletin below.
If you have any questions please contact Steve Waalkes at 800.678.9622 or by email at swaalkes@miconcrete.net.
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