the effects of fire on concrete
the effects of fire on concrete
(OP)
Apart from 'spalling' of concrete which occurs at high temperatures (in the fire condition), are there any other effects that the temperature or gases can have on concrete beams or columns?





RE: the effects of fire on concrete
Carbonation "softens" the concrete. It will ultimately become friable where carbonation occurs. If carbonation exceeds about 1/4 inch, treatment (removal and resurfacing) is necessary to protect the rebar.
Also, long term fire exposure (more than a couple of hours) will cause the chemical compounds achieve through hydration to begin to break down. While the result is usually deterioration and lower strength, it is not always easy to predict the extent.
RE: the effects of fire on concrete
What do you think about concrete exposed to salt water, particularly where reinforcement has deteriorated? I'm refering to the lowering of the pH and strength of the concrete. I am aware that the detiorating reinforcement
is a serious problem.
RE: the effects of fire on concrete
Ron
RE: the effects of fire on concrete
RE: the effects of fire on concrete
"amorphous compounds". What are amorphous compounds? Johann
RE: the effects of fire on concrete
RE: the effects of fire on concrete
Depending on the temperature, steel type, concrete cover and amount of spalling, the steel strength can be significantly reduced permanently by fire.
RE: the effects of fire on concrete
family's home, built around 1900, was recently gutted in a fire. Ironically, my grandfather built it out of concrete
because of his fear of fire. Is the strength of the concrete
compromised? I am asking for your opinion (I know you can only guess at the temperature reached, composition of the
concrete, etc.).
Sincerely, Carl Vermandere
cvermandere@juno.com
RE: the effects of fire on concrete
family's home, built around 1900, was recently gutted in a fire. Ironically, my grandfather built it out of concrete
because of his fear of fire. Is the strength of the concrete
compromised? I am asking for your opinion (I know you can only guess at the temperature reached, composition of the
concrete, etc.).
Sincerely, Carl Vermandere
cvermandere@juno.com
RE: the effects of fire on concrete
Using a screwdriver, scratch the concrete with moderate force. If the gouge is more than about 1/16-inch deep, you might have a concrete problem. Compare you gouge to an area where you know the concrete to be good.
Usually house fires do not last long enough to do much damage to concrete, other than thermal cracking and sudden shrinkage when the fire is extinguished. Localized spalling is to be expected. To compromise the strength, the fire has to exceed about 600F for several hours. Concrete is a good insulator from fire and usually fairs quite well. Your grandfather knew what he was doing!
RE: the effects of fire on concrete
Are you only interested in the effects on the concrete or also on the reinforcement inside the concrete.
If the temperatures are hot enough, the reinforcement strength could be reduced significantly.