Fire resistance of reinforced concrete columns with elastically restrained thermal elongation

This paper outlines experimental research on the behaviour of reinforced concrete columns with restrained thermal elongation subjected to fire. The high temperatures developed in a fire lead to the thermal elongation of the structural elements, but other parts of the structure that remain at lower temperatures will impose restraints on that elongation, resulting in additional stresses on the heated members. It is therefore important to analyze the influence of the thermal restraint on the behaviour of reinforced concrete columns subjected to fire. Fire resistance tests were carried out on reinforced concrete columns with restrained thermal elongation to study this phenomenon. The influence of several parameters on the behaviour of the columns subjected to fire was tested, including the longitudinal reinforcement ratio, the slenderness of the column, the restraint level, the load level and the load eccentricity.