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Highlights • Tensile behaviour of different GFRP laminates under elevate temperatures has is investigated. • Laminates with continuous unidirectional fibers showed the best tensile performance. • Laminates with chopped strand fibers showed the weakest tensile performance. • Laminates with continuous woven fibers performed better than chopped strand and weaker than unidirectional laminates. Abstract This study was aimed at gaining an improved understanding of the behavior of glass fiber-reinforced polymer laminates at elevated temperatures by means of testing laminate specimens with unidirectional, woven, and randomly distributed (chopped strand mat) fibers. The testing parameters were temperature, the type of fiber, and the thickness of the laminates. The failure modes of the specimens and their elasticity moduli at ambient temperature were investigated, and analysis of variance was conducted to determine the contribution of each parameter to the behavioral test results. The findings showed that among the parameters, an increase in temperature exerted the strongest effect on the specimens. The unidirectional laminate specimens exhibited the best performance, maintaining nearly 40% of their loading capacity at 550 °C. At this temperature, the woven laminate specimens could not carry any tensile load, and at 400 °C, the laminate specimens containing randomly distributed fibers lost all their strength. [ABSTRACT FROM AUTHOR]

The performance of beam-to-column connections is a key factor in the behaviour of moment-resisting frames (MRFs) under fire conditions. In this work, the behaviour and failure mechanisms of a half-scale 3D frame, composed of single-bay, single-storey MRFs and Braced Frames, in two perpendicular planes, equipped with 6 mm thick flush end-plate connections, under fire conditions was studied. A 'scaled' ISO 834 standard fire curve was followed during fire loading of the frame. The maximum reached temperature was 1100 °C. The temperatures of the elements of frames were measured at 2-minute time intervals. The rotations of the connections and the deflections of the MRFs' beams at these time points were worked out using an image processing technique. Furthermore, the effect of the ductility of connections was investigated by comparing the results of this study with those of a previous one in which less ductile connections were used. The results showed that the connections used in this study could sustain large rotations of up to 0.7 radian and endure 65 min under fire. Moreover, it was found that using flexible connections (connections with thinner end-plates) enhances the 'robustness' of moment frames in fire. • Scaled experimental models can be used to predict behaviour of structures in fire. • Image processing can be used for measuring deformations and rotations in fire tests. • Thickness-induced flexibility of thinner end-plates increases structural robustness. • Thinner end-plates reduce risk of over-stretching of bolts & structural collapse. • Simulated 'real fire' in this work triggered all forms of failure but overall collapse. [ABSTRACT FROM AUTHOR]

This study investigates the tensile properties of various GFRP laminates after exposure to elevated temperatures. Fiber configuration, exposure temperature and laminate thickness were considered as the test variables. A total number of 180 specimens were tested in tension to obtain the mechanical properties of GFRP laminates. Alongside the mechanical tests, SEM analyses were conducted on selected samples before testing to investigate the resin, fiber, and their interface damages. Regardless of the sample type, it was generally observed that the reduction rate in the tensile strength increased with an increase in the exposure time and a decrease in the laminates' thickness. The results of tensile tests after exposure to elevated temperatures showed that the laminates with continuous unidirectional fibers performed the best, laminates with chopped strand randomly distributed fibers performed the worst, and the performance of the laminates with woven continuous fibers was somewhere in between. The maximum tensile strength reductions for the unidirectional and woven laminates were about 50% after exposure to 300 °C, whereas random chopped strand laminates lost almost all of their load carrying capacity under this exposure condition. [ABSTRACT FROM AUTHOR]