Evaluation of the fire performance of unprotected composite beams with fin-plate joints

Abstract

Purpose

This paper aims to investigate the fire performance of composite beams when considering the hogging moment resistance of the fin-plate beam-to-girder joints including the effect of continuity of reinforcements.

Design/methodology/approach

Experiments on composite beams with fin-plate joints protected only at the beam ends are conducted. The test parameter is the specification of reinforcement, which affects the rotational restraint of the beam ends. In addition, a simple method for predicting the failure time of the beam using an evaluation model based on the bending moment resistance of the beam considering the hogging moment resistance of the fin-plate joint and the reinforcement is also presented.

Findings

The test results indicate that the failure time of the beam is extended by the hogging moment resistance of the joints. This is particularly noticeable when using a reinforcing bar with a large plastic deformation capability. The predicted failure times based on the evaluation method corresponded well with the test results.

Originality/value

Recent studies have proposed large deformation analysis methods using FEM that can be used for fire-resistant design of beams including joints, but these cannot always be applicable in practice due to the cost and its complexity. Our method can consider the hogging moment resistance of the joint and the temperature distribution in the axial direction using a simple method without requirement of FEM.

Citation

Yotsumoto, N., Hirashima, T. and Toyoda, K. (2022), "Evaluation of the fire performance of unprotected composite beams with fin-plate joints", Journal of Structural Fire Engineering, Vol. 13 No. 4, pp. 575-594. https://doi.org/10.1108/JSFE-05-2021-0032