Reduced service life of concrete sleepers due to inadequate design

Abstract

During the 1980's, the twin-block concrete sleepers/ties -designed and laid in railway lines with maximum operational speed of 200 km/h in France- which were laid on a track with maximum operational speed of 140 km/h in Greece, presented serious cracks in a percentage of more than 60% of the total number of this type of sleepers on track. This fact implies either inadequate design and/or insufficient strength of the concrete sleepers. The materials: concrete and reinforcement as well as the concrete sleepers met the strength specifications for design. The existing theories for the calculation of the design loads could not justify the appearance of these cracks since the calculated actions on sleepers were much lower than the limit values. In this paper an investigation is presented for the causes of this phenomenon that implies an inadequate design of the sleepers. © 2010 Taylor & Francis Group, London.