“Tuned like a piano”
“The project was managed in cooperation with Skanska, and they were responsible for the detailing of the constructions and the procurement of the materials used.” Skanska opted for Rockdelta after a lengthy period of calculations and comparisons of possible solutions for the vibration issues. Also the experts from Max IV were involved for their end of the line. “Skanska calculated the performance and the thickness and types of the mats.” This cooperation eventually led to the use of literally all available Rockdelta product thicknesses. In some area’s specific requirements even necessitated several layers of mats. “They tuned that track like a piano,” as one of the constructors observed.
Choice based on performance of the solution
“In the choice of the Rockdelta system Skanska evaluated a lot of factors including performance, pricing, sustainability, longevity and also the logistics and working conditions on the construction site.” says Von Strokirch.
The tramway infrastructure is designed to withstand the low temperatures and weather conditions in Sweden. Rockdelta is made of stone wool and the mats have an extended lifetime with retained functional performance even under extreme conditions. The lightweight mats are easily handled and can be stored outdoors without any impact on the quality.
Keeping the system dry
Rockdelta mats can be installed on surfaces that are not completely even and do not have to be glued or welded together. This was a definite advantage in this project, where one of the requirements was that no water should stay in the tracks. The small gaps between the mats function effectively as natural drainage system.
The only suitable solution
Rockdelta is applied as a resilient mat at the basis of a track system, where it decouples the track from the ground. Situated in the substructure the mats combine optimum acoustic performance with minimum rail deflection. Von Strokirch: “For this project, with a track system with longitudinal beams and ballast, we found Rockdelta to be the best solution”