Experimental fire performance assessment of a new type of prestressed composite circular precast concrete columns

•A new column form (PCCPCC) contains precast pipes, in-situ concretes and rebars.•The fire resistance of PCCPCCs is examined in full-scale tests and simulations.•The dominating role of axial load on the fire resistance is confirmed.•The precast concrete pipe provides an evident thermal isolation effect. The purpose of this paper is to study the fire resistance of a new type of prestressed composite circular precast concrete column (PCCPCC) consisting of a prestressed precast concrete hollow pipe and cast-in-place core concrete filled in the hollow section through a combined numerical and experimental approach. The potential advantages of PCCPCCs lie in their low manufacturing costs and high construction efficiency. A series of fire tests were conducted on PCCPCCs with consideration of different precast concrete strengths, rebar layouts, and axial loads, where the column damage patterns, fire exposure time, and vertical displacements of all the specimens were experimentally examined. Their post-fire residual strengths were also determined via uniaxial compression tests. Finite element (FE) simulations were also conducted and the obtained results were compared to the corresponding test outcomes. The results show that the fire resistance of PCCPCCs is largely dependent on the imposed axial loading, and an effective thermal isolation effect from the prestressed precast concrete hollow pipes was identified. The further research on this new column form is necessary for the possible future wide adoption.