Thermal response of pultruded glass fibre-reinforced polymer profiles subjected to outdoor environmental conditions

Fibre-reinforced polymer (FRP) composites have gained an increasing share of attention by the construction sector in the past few decades due to some of their advantages over traditional materials. However, there are concerns about the influence of moderately elevated temperatures on their properties. Despite the relevant advancements made in this field, previous investigations to characterize the mechanical properties of FRPs at elevated temperatures involved laboratory tests in steady-state conditions. However, for design purposes, it is also necessary to relate the material temperature with climatic conditions likely to be found in service and, in this respect, no information is available in the literature. Hence, the main objective of this study is to characterize the thermal response of pultruded glass-FRP (GFRP) profiles exposed to outdoor environmental conditions. To this end, this paper presents an experimental and numerical study about the influence of several parameters, such as surface colour (grey and yellow), cross-sectional shape (I- and tubular-shaped) and type of day (clear- and cloudy-sky), on the thermal response of GFRP profiles. The results obtained are used to propose design equations that allow determining the maximum material temperature as a function of the maximum air temperature in the shade, based on the philosophy adopted in EN 1991–1–5. For the conditions used in this study, the maximum material temperature is 21–23 °C (grey profiles) and 15–18 °C (yellow profiles) higher than the maximum air temperature in the shade. • Thermal response of pultruded GFRP profiles subjected to outdoor conditions is studied. • Experimental tests are conducted and advanced numerical simulations are performed. • Influence of colour, cross-section shape, wind velocity and sky conditions are studied. • Results are used to propose design equations based on the EN 1991–1–5 philosophy. • GFRP temperature can be up to 21 °C higher than maximum air temperature in the shade.