Structural Performance of Cable-Stayed Bridges with CFRP Cables Under Temperature Loads

Over the past few decades, there has been a growing interest in the use of carbon fibre-reinforced polymers (CFRP) for the cables of cable-stayed bridges due to their high strength, corrosion resistance, relatively high stiffness, good fatigue resistance, and high resistance to creep rupture. One notable difference between the mechanical properties of steel and CFRP is their coefficients of thermal expansion at 12 × 10^–6 °C⁻¹ and 0.6 × 10^–6 °C⁻¹, respectively, and it is conceivable that this difference causes bridges with CFRP cables to behave differently under temperature loads than bridges with steel cables. A literature review revealed that very few studies examine this topic. This paper studies the structural performance of cable-stayed bridges with CFRP cables subjected to temperature loads by creating finite element models of a cable-stayed bridge with a main span of 250 m, one with steel cables and one with CFRP cables, and comparing their performance. The two bridges were subjected to thermal expansion and contraction loads, which were determined using the requirements of CSA S6-19. This paper collects and discusses the following data: cable forces; axial force, shear, and bending moment in the deck; axial force, shear, and bending moment in the pylons; and vertical deck displacements. It was found that temperature loads significantly impact the behaviour of bridges with CFRP cables due to CFRP’s low coefficient of thermal expansion, and it is evident that this behaviour is also affected by the type of connection between the deck and the pylons.