Flexural behaviour of alternate transom using composite fibre pultruded sections

Abstract

Abstract Timber transoms have been installed in railway tracks around the world. These transoms are subject to frequent maintenance and replacement due to the degradation of timber. To reduce the maintenance issues associated with timber transoms, this paper will assess the behaviour of a virtually maintenance free material under static loading. This would provide financial and practical benefits to the Sydney Harbour Bridge's railway network by reducing the need for replacement and frequency of maintenance. Conventional alternative materials including steel and concrete have been extensively researched but are not viable for use in the Sydney Harbour Bridge railway system due to maintenance and weight issues. Composite steel-concrete panels utilise the best attributes of both materials to provide a solution that is lighter, reduces depth and will reduce installation time. While precast steel-concrete composite panels reduce the weight of concrete transoms, they are still quite heavy. Composite fibre material is a constantly developing material that is promising for use in transoms. The material possesses strong mechanical properties while reducing the weight and installation time relative to concrete solutions. There is limited research regarding the feasibility of composite fibre material for use in transoms due to the relatively recent development of the material. This paper presents a theoretical panel design solution using Wagners Composite Fibre Technology (CFT) pultruded hollow sections to cater for applied rail loads. Two composite fibre panels were fabricated and assembled using AJAX ONESIDE blind bolts and LINDAPTER blind bolts, and experimentally tested to investigate the panel's response to static railway design loads. The two blind bolts and the static experimental methodology were chosen to replicate previous experiments investigating composite steel-concrete panels for use as transoms. The composite fibre panel design successfully resisted a maximum load of 900kN and deflected less than the serviceability deflection limit. The results from experimental proved the flexural behaviour and deflection of the composite panel design is suitable for use as a railway transom under static loading. Further studies into the composite fibre panel such as impact testing and fatigue testing are required to make a supported conclusion regarding the feasibility of the composite fibre panel for use as a transom in the railway industry.