Aran van Belkom (M.Sc.) heeft tijdens de Rail eningeering conferentie 2015 in Edinburgh zijn paper gepresenteerd met de titel "RECYCLED PLASTIC RAILWAY SLEEPERS - Analysis and comparison of sleeper parameters and the influence on track stiffness and performance-" (beschikbaar in Engels).
- ABSTRACT-
In the last years, plastic railway sleepers have made their introduction. Amongst its characteristics, plastic sleepers have a good damping and a high design freedom. If used in the proper way, plastic sleepers can give improvements in the track. They should not be regarded as a substitute for wood or concrete, but use should be made of their own characteristics. Existing sleeper requirements are however applicable for wood or concrete and can hardly be seen as functional requirements suitable for the development of
plastic sleepers.
The desired track stiffness is the first parameter to define in setting requirements. A good compromise between bending stresses in the rail versus noise and vibration seems to be a target track stiffness of 50 kN/mm. When making a comparison between the different sleeper materials, the target track stiffness can be reached with plastic sleepers, where concrete tends to be on the stiffer side and wood shows more variations. Knowing the track stiffness gives the possibility to calculate the distribution of forces over the sleepers. Especially at irregularities in the track, such as bridges or viaducts, forces on sleepers can become high. Special attention to sleeper stiffness parameters should be given at those locations, as well to bending stiffness as to compression stiffness.
The sleeper stiffness parameters are input in calculating the system stiffness. Effects of sleeper bending stiffness on track stiffness, railhead stability and ballast contact stresses are discussed. For a 2600 mm sleeper, a 150-250 kNm2 bending stiffness seems appropriate, where for a 2400 mm sleeper the minimum bending stiffness should be higher. The sleeper stiffness also has effects on the strength requirements, as has the sleeper length. Where it is clear that every situation will be different, calculations have been done to give a mean value as an example. Every specific situation can be calculated accordingly.
Klik hier voor de complete paper 'RECYCLED PLASTIC RAILWAY SLEEPERS' (in Engels)
Klik hier om de paper in pdf op te vragen
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