Abstract

The concrete structures will absorb temperature when it is exposed to fire or explosion incident. Depending on the period of time of the absorbtion process, its’ temperature could reach over a few hundreds to less than a thousand degrees Celsius, this abnormally high temperature could affect negatively on its. Assessing the bearing capacity of the concrete after the accident is necessary for the structure’s safety. This article investigated the compressive strength of two types of concrete (polypropylene fiber concrete and plain concrete – control concrete) that are burned in conditions at three temperature levels (500oC, 700oC, 900oC) and during three periods of burning time (60', 120', 180'). The research results showed that: the fire incidents affected seriously on the compressive strength of both types of concrete; the greatest decrease of the compressive strength is about 70%; the compressive strength of polypropylene fiber concrete decreases with a rate higher than that of ordinary concrete, but their values are not much different