Calibration of a simplified method for fire resistance assessment of partially encased composite beams

Purpose-This paper aims to deal with the evaluation of the bending moment resistance of partially encased composite beams, heated from below by the standard-time temperature curve (ISO 834). Design/methodology/approach-EN 1994-1-2 provides two calculation models for evaluating the sagging and hogging moment resistance: the "general simplifed rules" and the "simplifed models" proposed in the Annex F. Findings-In this paper, these simplifed calculation models were implemented on several partially encased composite beams, by means of a parametric analysis. Then, the results were compared to those obtained through an advanced calculation model, such as the Moment-Curvature model, by means of a comparative analysis. Originality/value-The aim of the "parametric-comparative" analysis is the evaluation of the reliability of the Annex F simplifed models. This analysis was conducted by means of both numerical-numerical and numerical-experimental comparisons. This paper provides an alternative simplifed calculation model, which is easy to implement and very reliable.