Mechanical Performance of Reinforced Pultruded Columns for Curtain Walls

The present work is aimed at evaluating the mechanical performance of pultruded beams subjected to bending stresses through experimental tests. Such beams are intended to be used in a curtain wall construction system as a variant to a patent application (n.102020000025636) which includes wood columns. This variant wants to meet the need of smaller dimensions of the columns and keep guaranteeing the mechanical performance. The columns are made of pultruded I-beams, reinforced with glued metal plates and two prestressed threaded bars placed in the central axis of symmetry of the section. First, the materials (pultruded, steel plates, threaded bars and structural glue) are mechanically characterized; then, three types of columns are tested by means of a 3-point bending test and 3 loading/unloading cycles: (i) n. 1 beam with no reinforcement plates or pretension bars, (ii) no. 2 beams with reinforcement plates and no pretension bars, (iii) no. 2 beams with reinforcement plates and pretension bars. The maximum deformation in the elastic range for all reinforced beams (11.48 mm) is measured by applying a load of approximately 10 kN, corresponding to a wind pressure of more than double the requirement for windows (2000 Pa). The contribution of the threaded bars to the maximum applicable load is negligeable, which can be ascribed to their placement in the middle of the section. This first solution is chosen because of the small dimensions of the GFRP profile section.