New Developments in Road Trackway Construction

A precast concrete slab trackway system developed for road railways in the seventies and a trackway system with glued rail fastening on underground and overground trackways will be reported on in this paper. As experienced, the glued fastening system proved to be more favourable in use. The Great Boulevard, one of the most heavily trafficked streets in Budapest was reconstructed between 1994 and 1997. Based on the former experiences, the construction of a new trackway structure was decided. The new structure and its construction process will be reported on here. The composition of both the concrete mix for the slab supporting the tracks and the imprinted concrete applied as a surface course between the tracks will be shown. The most important characteristics of the earthwork formation, the cement bound basecourse, the concrete slab and the imprinted concrete will also be reported on. Some difficulties occurred in entraning the appropriate air content and air bubble distribution in the imprinted concrete due to the insufficient effect of the admixture in the presence of a cement with high fly-ash content at the beginning of the work.