Calcareous and granite aggregate concretes after fire

- Experimental research on residual mechanical properties of concrete.
- Influence of two cooling processes studied.
- Cooling by water jet has negative influence comparing to the one in the air.

This paper presents the results of an experimental research on the assessment of the residual mechanical properties of calcareous and granite aggregate concretes after fire. The influence of the following parameters was tested: the loading level (0.3 and 0.7fcd); the cooling process (cooling in the air and by water jet) and the maximum temperature that the concrete was subjected to (20, 300, 500 and 700 °C). The mechanical properties studied were the residual compression, direct and splitting tensile and flexural strengths, modulus of elasticity and Poisson's ratio. The results showed in general that the higher the temperature and faster the cooling process is, as the one by water jet, the higher the negative impact on the residual mechanical properties of the concrete is, being the strength nearly null for above 600 °C.