Durability of CFRP strengthened circular hollow steel members under cold weather: Experimental and numerical investigation

• Strength reduction was noticeable for CFRP strengthened steel member in cold weather.
• CFRP with higher modulus increases the durability of beam significantly.
• Durability design factor is proposed for cold weather.

The durability of carbon fibre reinforced polymer (CFRP) strengthened steel circular hollow section (CHS) member under prolonged cold weather has not been explored sufficiently. Furthermore, various parameters that may affect the durability of such members have not been revealed yet. This paper presents an analytical and experimental study with a finite element (FE) approach to study the effects of prolonged cold weather (+3 °C) exposure on CFRP strengthened CHS member subjected bending. It was found that a prolonged exposure about 12 month cold weather immersion adversely affected the durability of strengthened beams by reducing strength and stiffness. Durability design factor has been recommended. The proposed analytical models and FE models were found in good agreement with the experimental results. The results of parametric studies showed that the durability design factors varied from section to section, CFRP with higher tensile modulus and higher number of CFRP layers performed better in cold weather.