Parking Bumpers

[mgardina]

We have run into parking bumpers installed in northern climates that are disintegrating. We are told they used air entrained concrete. The concrete just flakes off at the touch. In some cases 1/3 to 1/2 are gone. Has anyone else experienced this and know what might be causing it?

 

[jimbo]

Vendor quality, usually because of insufficient cement content in the concrete, is the reason. AE concrete should be used.

Find a reliable vendor.

 

[cvg]

what about de-icing? Salt is tough on concrete

 

[dik]

We normally spec a minimum of 32MPa (4500psi) for concrete exposed to salt along with a minimum cement content. Also 5 to 7% air for freeze-thaw...

It sounds like the concrete is delaminating due to freeze-thaw. In addition to salt messing with the passivity, it also alows for the surface to go through more freeze thaw cycles.