Barchip is exhibiting at AusRail 2016, 22 to 23 November 2016 at the Adelaide Exhibition Centre. AusRAIL is the largest rail event in Australasia and is supported by the leading industry associations, including the Australasian Railway Association (ARA); Institution of Railway Signal Engineers (IRSE); Railway Technical Society Australasia (RTSA); & the Rail Track Association Australia (RTAA). For information visit the AusRail website.

Todd Clarke from Elasto Plastic Concrete will be presenting the paper; “A Cost-effective alternative to conventional concrete track slab design and construction”.

Abstract.

As the spending on rail infrastructure in Australia increases, the need for innovative solutions to track design and construction intensifies. Traditionally, track has been laid on ballast material which provides a relatively stiff bearing surface which is able to transfer the train loads through to the ground below. However, as train loads get larger, and speeds increase, maintaining the durability of ballast material becomes more challenging. At high speeds, or with heavy loads, this ballast can be pulverised, causing the track levels to shift, which can jeopardize ride quality and safety. More recently, concrete track slabs have been used as an alternative to ballasted track systems, particularly for high speed rail, to overcome these issues. They have also become commonplace in metro light rail construction, where the rail corridor is shared by road traffic, and the rail is embedded into the concrete track slab. Concrete track slabs are used as they provide a longer design life and require less maintenance than traditional ballast systems. Their application is seen more regularly in situations, such as tunnels or bridges, where ballast is difficult to place, or using it impacts on the alignment of the structure.

Traditional concrete track slabs require a higher initial investment than ballasted systems, making the option less attractive. The use of macro synthetic fiber reinforcement allows a significant reduction in the initial cost of using concrete track slabs, while removing the durability concerns associated with stray current corrosion of reinforcement. Stray current corrosion of particular concern in concrete track slabs which use electrified rails, such as those used in modern light rail systems. These systems require significant effort in the design and construction of the reinforcement to avoid stray current corrosion and require continuous monitoring, hence the use of macro synthetic fiber reinforcement alleviates this concern, creating a more efficient and cost effective design.

This paper intends to create a point of discussion for track slab designers, owners and operators on the use of macro synthetic fibers in track slab construction. It will provide an outline of the method used for design and analysis of the macro synthetic fiber reinforced track slabs, as well as guidance on construction practices that can be used to optimise the installation and performance of the track slab. The paper also includes some case studies where macro synthetic fibers have been used as the reinforcement for various track slabs internationally, and the design and construction practices that were used for each of these projects will be discussed.

For more information contact your nearest Barchip representative.