Coloured self-compacting concrete for the new train station in Herstal, Belgium - A case study

Abstract

The project of the new train station in Herstal, Belgium stands as the new landmark of the city. Now connecting city parts previously disconnected, the high tower of the station ensures visibility and grows into an emblematic symbol for the town. Beyond the strength of the architectural shape itself, the concrete building has a solid colour, namely red. For its flexibility and in order to fulfil the structural and aesthetics requirements of the tower, ready-mix concrete has been chosen. In addition, the self-compacting property of the concrete has given higher insurance of meeting the requirements for the aesthetic aspect of the surface. This paper redraws the main steps in the development, the production and the pouring of a self-compacting red concrete used for the construction of the building. In the absence of a specific standard at the time of the project development, the specifications and the properties of the concrete have been established in order to secure a high quality of the product but also its stability during the production process. In that matter, laboratory tests in cooperation with all actors (prescriber as well as concrete manufacturer) have led to quite precise specifications of the concrete. Furthermore, this paper deals with all aspects of working with aesthetic concrete during the building phase, namely the preparation of the formworks, the phasing, and the several rules to be applied in terms of maturation of concrete. At last, aesthetic evaluation of the surface and maintenance aspects are also issued.