Temperature analysis on fire resistance experiments of partially encased beams

Twelve fire resistance tests, grouped in four series, were developed using partially encased beams (PEB) without concrete slab, for different load level and shear connection. PEB were built with standard hot rolled IPE100 profile and reinforced concrete between flanges. Fire resistance was determined for standard ISO834 nominal heating curve, using small fire resistance furnace and portal frame. Temperature was measured in three different sections along PEB length, for three different materials (steel, concrete and reinforcement). Average temperature in each section and material was compared to the average over length temperature. Each series presented similar results, with good reproducibility. Special focus was given to critical temperature. The maximum temperature difference between sections S1, S2, S3 and the average element length temperature is smaller than 3.2 % for test series 1. For test series 2, 3 and 4 the maximum temperature difference is smaller than 5.1%, 6.3% and 11.2%, respectively. Temperature is not uniform in cross-section. After the initial heating stage, temperature revealed a constant difference of approximately 150ºC between temperatures measured inside and outside, defining two main temperature evolutions. Temperatures measured outside revealed always higher temperature level