Quality management of the concrete carriageway and intermediate slab installation in the tunnel / Qualitätsmanagement Betonfahrbahn und Zwischendeckenbau im Tunnel

Based on the experience of former tunnel construction projects, the project management appointed an independent quality assurance consultant in addition to quality control by the site supervision for the construction of the intermediate slab and the concrete pavement of the new second tube of the Tauern Tunnel (direction Salzburg). In relation to the concrete pavement with exposed aggregate finish and the intermediate slab, quality assurance measures included the inspection of the suitability certificates and expert support in construction preparation and concreting. Compliance with the technical conditions of contract was also monitored continuously.
For the road pavement construction, particular emphasis was placed on the quality of the pavement concrete and the exposed aggregate finish. For this reason, the first few days of pavement construction were subjected to increased checks, until the concrete production, transport logistics and construction crew had got used to the specific conditions in the tunnel and a homogeneous exposed aggregate finish could be guaranteed with the required functional properties like skid-resistance and noise-reducing texture.
Construction of the intermediate slab was prepared in advance by casting a test slab as agreed with the specialist in order to check that the required construction quality could be achieved with the chosen process. The experience with the test slab led to an optimisation of the construction process and the implementation of this and maintenance of the quality requirements were supervised during the construction work.