ABSTRACT

Generally, concrete structures have a very good fire resistance. Although damage to the concrete gradually appears with increasing temperature, it is possible to repair the structure after an adequate assessment. To do this in a systematic way, knowledge is necessary concerning residual material properties and methods to assess this strength. Since the residual strength is temperature dependent, methods may be used to assess the strength indirectly by measuring the alteration in the material as a function of the temperature. A paper by Annerel (Annerel & Taerwe 2007) illustrates how cracks appear and the colour of the concrete changes from red (300-600◦C) to whitish grey (600-900◦C) and buff (900-1000◦C). Once these temperatures are obtained, simple calculations based on EN1992 (EN1992-1-2-2004) may be used to determine the residual capacity of concrete elements, as elaborated in a paper by Taerwe (Taerwe, Poppe et al, 2006).