Concrete degradation due to heat 2

[DieselGuy]

I have large diesel generators that occaisionally exhaust into a concrete enclosure. The concrete was originally specified as 5000 PSI minimum. The exhaust has plenty of exit points from the structure but the exhaust will impinge on a concrete roof approximately 4 ft from the pipe exit. Exhaust temperature are approximately 600 Deg F at the exit. Any references or thoughts on the affects of the structure due to short term exposure (an hour or two) or long term exposure (7 to 31 days) to this type of heat.

 

[Ron]

DieselGuy...the thermal levels you have will not materially affect the cementitious bonding (and thus the strength of the matrix), but could cause some localized spalling, particularly if the concrete gets wet before the heating.

The most likely problem you will have is that of carbonation development at the surface of the concrete due to the exhaust gases and the heat. This will cause surface deterioration of the concrete. I would suggest coating the concrete surface to mitigate this potential.