The behavior of concrete under fire is being studied by a group at the Structures and Civil Engineering Laboratory of the Civil Engineering, Archi- tecture and Urbanism College in UNICAMP. This work presents an investigation on the loss of mechanical strength of different concrete mixes after submitted to high temperatures and on the influence of rehydration. Mixtures were prepared with three different aggregates: expanded clay, basalt and limestone. Test bodies were submitted to temperatures of 300 ºC and 600 ºC under the same heating rate as that of Curve ISO-834 (1999). After heat treatment, some of the test bodies were rehydrated in air, some were immerged in water and others were wrapped up in plastic film dur- ing 28, 56 and 112 days. At these ages, concretes were evaluated in relation to compression strength, tension strength and modulus of elasticity, therefore providing an assessment of the influence of the aggregate type and rehydration on the recovery of mechanical strength.
concrete; high temperatures; mechanical properties; rehydration