Tried and tested throughout.
Installation.

The superstructure construction of the “System NBU” consists of the rails, the Krupp ECF rail fastener, the concrete load-bearing course (BTS) and the hydraulically bound load-bearing course (HGT). Its deflection and attenuation are defined and it requires a low-deformation bedding on earthworks/ground constructions, on bridges and in tunnels.

On the slab track “System NBU”, a sliding-formwork finisher makes a continuously reinforced concrete load-bearing course (BTS) with longitudinal grooves for accommodating the anchor bolts of the Krupp ECF rail fastener. The long rails already equipped with the rail fastening system are fixed in position via the longitudinal slots of the BTS at precise height position and lateral position. The anchor bolts of the rail fastening system are then grouted and smoothed in the longitudinal slots of the BTS system.

The quality of the hydraulically bound load-bearing course (HGT) corresponds to that of a concrete C 12/15 (B 15). Installation is in one or several layers depending on thickness.

The BTS is the upper, bound load-bearing course of the slab track. It is reinforced throughout and is initially compounded without joints with concrete quality C 30/37 (B 35). The BTS is reinforced lengthwise continuously with 20 x BSt 500 S steel sections for constructional purposes with a diameter of 20 mm. In the transverse direction, steel sections for constructional purposes, with a diameter of 14 mm, are arranged at 20 cm intervals. This means that the reinforcement share is at least 0.84%, as specified.

Finally, dummy joints are produced by notching (minimum depth 120 mm), thus ensuring crack-width limitation < 0.5 mm (controlled cracking) in the entire structure. After calibration and fixation of the rail position, the lengthwise slot is grouted with special grouting.