António M. Correia

Experimental Research on the Load-Bearing Capacity of Partially Encased Steel Columns Under Fire Conditions

The composite steel and concrete columns are known to have enhanced fire behaviour when compared with bare steel columns. However there are still aspects that must be clarified, as the influence of the building surrounding structure on the fire resistance of the columns. In this paper, the results of fire resistance tests on partially encased steel columns carried out with two different experimental systems are compared. In one of the experimental systems, the building surrounding structure is materialised by a steel restraining frame, and in the other is performed by the so-called substructuring method. Due to the concept of hybrid substructuring, the entire building is decomposed in two parts: one is represented by the building element under test, whereas the remaining building is simulated numerically in a computer. The main conclusion drawn from this work was that the surrounding structure has a major influence in the development of axial forces in the test columns. Moreover, it was observed that the higher the non-dimensional axial restraint ratio the lower the critical time of the columns.

Influence of Brick Walls on the Temperature Distribution in Steel Columns in Fire

This paper reports on a study of steel columns embedded in walls in fire. Several fire resistance tests were carried out at the Laboratory of Testing Materials and Structures of the University of Coimbra, in Portugal. The temperatures registered in several points of the experimental models are compared with those obtained in numerical simulations carried out with the SUPERTEMPCALC finite element program.