effect of fire on concree

[rittz]

A single story house burns down. All the debris eventually falls into the basement and continues to burn. The fire is put out before it completely burns to ash. The charred remains is cleaned out of the basement. What evidence will there be that the concrete foundation and/or the concrete floor is damaged and should not be reused in constructing a new house on the foundation? Is it useful to cut a core and do a compression test? Apparently clean-up firms can clean the surface and seal it and guarantee there will be no odor in the future.

 

[msquared48]

Any spalling or large cracking exposing damaged, conpromised rebar for one. If it is hear a rebar splice, splice bond strength could be affected.

Any metal plates or bolts to the concrete could be compromised.

There are meters to measure the f'c of the concrete after the fire to determine the level of damage.

Mike McCann
MMC Engineering

 

[Ron]

As Mike mentioned, look for spalling, though that is more often a result of extinguishing the fire than the fire itself (sudden cooling, steam in pores, etc.).

The most common detriment is carbonation. A petrographic examination of a concrete core can tell the depth of carbonation. It can also determine microcracking in the paste and aggregate.