Effect on Concrete

Fire effects on concrete:

Effect of fire on the concrete depends on the mixing ratio and its components, and through complex physical transformation of the heating process. Transient creep of concrete will be heated, elevated temperature changes the microstructure of concrete, which may damage the occurrence of loss of bending and tensile strength; the loss of bond strength; the loss of shear and torsion strength; loss of compressive strength; micro-cracks and concrete spalling.

There are three methods to assess fire performance, (1) fire tests; (2)prescribed method, which is rigid; and (3)performance-based approach, which is flexible. Performance-based methods can be divided into three categories: (i) Analysis calculated based on the limit state; (ii) thermo-mechanical finite element analysis; (iii)overall thermal finite element analysis.

Load-bearing structural elements should be designed to function in case of fire does not fail to ensure that elements within acceptable limits heat transfer and reinforcement average concrete thickness sufficient to maintain the temperature below the threshold required for a long enough time for the refractory. Reduce the risk of concrete bursting, you can use a thermal barrier to protect the exposed concrete surface. We can use the lightweight concrete, which has an insulating property, and this compared to the same thickness as ordinary concrete transmit heat slowly. Thus typically provides enhanced fire resistance. Concrete severely damaged by fire removed from behind the steel reinforcement bars, at least one rod diameter depth. Instead of concrete to be removed, applied polymer-modified cementitious material or spray applied cementitious repair materials.

corrosion effects on concrete:

Contact with the concrete surrounding medium, such as air, when water (sea water) or soil containing different concentrations of acid, alkali and salt erosion was when they penetrate into the interior of the concrete, after...