As defined by the American Concrete Institute (ACI) Committee 116, scaling is the “local flaking or peeling away of the nearsurface portion of hardened concrete or mortar.” This may also be called mortar flaking when it occurs just over the aggregates near the surface. Scaling is primarily a physical action created by hydraulic pressures or stresses from repeated freeze-thaw cycles within the concrete. The expansive forces caused by ice formation are exacerbated by deicing chemicals, which increase the concrete's saturation and the number of freeze-thaw cycles. The distress mechanisms of scaling are complex on both a
microscopic and macroscopic level.
The State of Michigan is in a “severe exposure” climate where exterior concrete is subjected to i) continuous moisture, ii) cycles of freezing and thawing, and iii) the use of deicing chemicals. Therefore, exterior concrete must be proportioned with durable ingredients designed for this type of climate, with an entrained air void
system, and such concrete must be placed using proper placement, finishing, curing, and protection to resist hydraulic pressures (stresses) that can cause scaling.
The most common causes of scaling are related to one or a combination of the following factors:
To read more about the causes in detail, as well as, preventing and minimizing scaling and repair or treatment of scaled concrete surfaces, download our full bulletin below.
