Thermal Performance of Unloaded Spiral Strand and Locked-Coil Cables for Bridge Infrastructure

There are no contemporary code requirements for the fire resistance of bridge infrastructure, nor is there guidance available for practitioners who wish to design cable-supported structures for fire. This research seeks to develop an understanding of the thermal response of steel stay-cables under exposure to a pool fire. Multiple varieties of stay-cable are instrumented with thermocouples and heated by a methanol pool fire. Novel imaging techniques observe the cables surface during heating and cooling and enable the calculation of thermal strains and deformations. Results show a normalization of cross-sectional temperatures outside of the localized heating region for cable diameters up to 140 mm, provide comparisons of heat transfer behaviours for different cable sizes and configurations, present a novel thermal rotational effect, and calculate cable thermal expansion values. Predictive thermal expansion values provided by the Eurocode were shown to underpredict cable thermal expansion in most cases.