Precast Concrete Railway Track Systems

Book excerpt: In 1986, the FIP Commission on Prefabrication issued the state-of-art report "Concrete Railway Sleepers", which included design considerations, manufacturing methods, rail fastening systems and field performance. During the two decades since that report, precast concrete has gained importance in the field of railway track systems for plain track, switches and crossings, tunnels and other applications. Developments in production methods for concrete sleepers in switch and crossing layouts to cope with the complex geometry and the industry's confidence in their performance have contributed to the huge increase in the use of this type of sleeper. The use of slab track for high-speed track has also grown, particularly where either new track is built or where existing track is renewed and long periods of track possession are possible. There has also been progress in the development of plant and equipment for the installation, renewal and maintenance of concrete sleepered track. With machines now able to replace existing track at a rate of 5000 sleepers (over 3 km track) per day, choosing concrete sleepers can reduce the time on site, meaning tracks can be reopened quickly whilst reducing labour requirements and costs. Today, precast concrete is considered to be the best performing and preferred material for railway sleepers, due to the following factors: long-term durability; improved geometric retention of track and greater weight vital for high-speed and heavy freight lines; improved elasticity of track; improved ride quality; low first cost; minimum life cycle cost; low cost of maintenance; environmental friendliness - no chemical treatment required and can be recycled. As all aspects of precast concrete railway track systems, from design through manufacture to installation and maintenance, have progressed since the publication of the FIP report, an update was considered timely, in order to provide a synthesis of currently available information. This new edition covers quality, design, production, durability, maintenance and environmental considerations, and includes survey on the use of precast concrete track systems in over 30 countries.