Composite railway sleepers - recent developments, challenges and future prospects
A number of composite railway sleeper technologies have been developed but their applications in rail tracks are still limited. This paper rigorously reviews the recent developments on composite sleepers and identifies the critical barriers to their widespread acceptance and applications. Currently the composite sleeper technologies that are available ranges from sleepers made with recycle plastic materials which contains short or no fibre to the sleepers that containing high volume of fibres. While recycled plastic sleepers are low cost, the major challenges of using this type of sleepers are their limited strength, stiffness and dynamic properties which in most cases, are incompatible with those of timber. On the other hand, the prohibitive cost of high fibre containing sleepers limit their widespread application. Moreover, limited knowledge on the historical long-term performance of these new and alternative materials restricts their application. Potential design approaches for overcoming the challenges in the utilisation and acceptance of composite sleeper technologies are also presented in this paper.