Assessment of the degree of heating of lightweight concrete

Estimating the fire severity and temperature of structural elements in buildings during fire action is one of the primary factors for assessing their condition after a fire. Some existing traditional methods for assessing this temperature, such as visual inspection, hammer sounding and petrographic analysis, are well established. However, owing to the significant variation of the results it is highly advisable to conduct cross-checking by using parallel approaches. The aim of this paper is to offer initial information about the development of a novel approach, in addition to the traditional methods for estimating the degree of heating of normal and lightweight (lightweight expanded clay aggregate) concrete, which could be beneficial for cross-checking. This approach is based on results from an experimental study concerning the reduction of compressive strength of concrete after high-temperature exposure. Developed analytical correlation between the reduction of strength and the degree of heating is presented by way of parabolic equations. Further verification and consequent testing of the proposed methodology will allow a good estimation of the maximum temperature of different parts of fire damaged buildings to be obtained. It will provide an opportunity to use this information, as an additional tool, to estimate the condition of the remaining structure after a fire, in order to propose appropriate repairing methods.