Effects of Freeze-Thaw Cycles on Exposed Concrete? 2

[IJR]

My very dear friends

I came across a very interesting technical report on a "forgotten" large reinforced structure built in a very cold area which also supports a steel roof. Several elements collapsed and concrete walls misbehaved reason being simply the freeze-thaw cycles

up to 2.0" (5.0cm) of concrete can be easily scaped off with a metal spoon.

If this can happen to a building, what of RC tanks?

Can anyone provide more insight on this important phenomenon?

My respects
IJR

 

[Ron]

Freeze-thaw is a common durability problem with concrete in certain climates. Most often, air entrainment is used to keep the freeze-thaw damage in check. This works by allowing microscopic expansion to occur against the many entrained air bubbles, thus decreasing strain accumulation at localized points, which leads to scaling and cracking.

Keep in mind also, that if the concrete is sealed against moisture intrusion, the effects of freeze thaw are greatly reduced, with or without air entrainment.

RC tanks are as susceptible to freeze-thaw as buildings, though their temperature cycles are probably fewer since they are not typically heated on the inside as buildings are.

 

[CarlB]

Information regarding freeze-thaw action in concrete is included in ACI 201.2R-92 "Guide to Durable Concrete".