Fire Damage To Concrete Slabs

Most fire damaged structures can be successfully repaired this being the more cost effective solution than demolition and reconstruction.

Fire damage to concrete slabs.

A serious house fire can generate enough heat to damage and weaken the concrete and steel reinforcement bars in footings slabs and footing stem walls. Although in many cases concrete can withstand the effects of fire and retain much of its load bearing capacity exposure for a long time or to too intensive fires can seriously damage the concrete. Fire doesn t damage concrete immediately as it damages wood. However it can take up to three hours for the heat to penetrate through the concrete cover to the steel reinforcement.

For short term exposure concrete is fire resistant enough to survive undamaged. Concrete can be damaged by heat. Repairing cracks in concrete is usually inefficient as they will remain weak spots in the concrete base. Consult an engineer.

However the visual appearance of concrete after a fire can be quite shocking with extensive blackening often accompanied by spalling and cracking. Blast the soot from the surface of the concrete with either a dry ice mixture or sand. Prolonged exposure to high temperatures like the ones generated from a wood burning fire pit however can cause the concrete base to crack and spall over time. Determine what kind of repair is necessary by using a concrete rebound hammer.

If the bottom side of the slab is subjected to fire the strength of the concrete and the reinforcing steel will decrease as the temperature increase. All rc bubble slab exposed to 300 and 400 spalling occurred damage of spalling for bubble slabs exposed to 300 in 30 minute fire duration more than 400 by 32 otherwise at 60 minute. Before carrying out any repair it is necessary to determine the extent of the damage to the concrete and reinforcement and hence their residual strengths. Buildings parking garages bridges and concrete lined tunnels are examples of structures that can be damaged by fire.

Digital rebound concrete hammer. Being able accurately to assess the condition of concrete after a fire is important not only for safety reasons but also for economic reasons. How to repair fire damaged concrete step 1. If the lateral support of the foundation was altered by the events related to the fire it is possible the foundation wall could be subjected to excess stress causing it to crack tilt or deflect.

Fire damaged concrete spalling of concrete to beams and a column caused by fire concrete has good fire resistance and concrete structures generally perform well when fire damage occurs.