Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or '+'-shaped cross sections. The number of fire resistance tests on circular reinforced concrete columns with elastically restrained thermal elongation is still very small. In order to examine the influence of several parameters on the behaviour in fire of this type of columns several fire resistance tests were carried out. The parameters tested were the load and restraint level, slenderness of the column and longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 standard fire curve and the critical time (fire resistance) and temperature and failure modes were determined. The test results showed that the spalling phenomenon may occur in circular columns and so reducing its fire resistance. The increasing of the load level led to a reduction while the increasing of the longitudinal reinforcement ratio or the decreasing of the slenderness of the columns led to an increasing of their fire resistance. The restraint level might not be much relevant on the fire resistance of circular reinforced concrete columns.
Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or ‘+’-shaped cross sections. The fire resistance of these columns is probably more compromised than in circular columns due to the phenomenon of concrete detachment in the corners of the cross-section. In order to examine the influence of several parameters on the behaviour in fire of circular reinforced concrete columns with restrained thermal elongation, several fire resistance tests were carried out. The parameters tested were load, restraint level, slenderness of the column and the longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 Standard fire curve and the critical time and temperature and failure modes were determined. The test results mainly indicated that the spalling phenomenon may also occur in circular columns and so reducing its fire resistance. The restrained level might not so much relevant concerning the fire resistance of circular reinforced concrete columns.