Assessing concrete strength in fire-damaged structures

The paper presents a review of concrete assessment methods: laboratory and in situ (non-destructive and semi-destructive tests) in application to reinforced concrete structures after fire. One of the most important phenomena affecting the load-bearing capacity of these structures is the reduction in concrete strength at high temperature and after cooling. Traditional test methods, commonly used in normal conditions (e.g. destructive test on core specimens), usually do not take into account the non-uniformity of concrete after a fire. Therefore, other methods are proposed to determine the depth of the damaged concrete in the external layers of a given structural member.