BarChip outperforms all others to be selected for the fibre reinforced shotcrete lining in the Divača-Koper Second Track tunnels.

BarChip fibre reinforced shotcrete was used for the primary tunnel linings of the Divača-Koper Second Track railway tunnels. The Divača-Koper railway holds a pivotal position in Slovenia’s transportation infrastructure, serving as a vital link between the inland regions and the Adriatic Sea. Started in 2021, The EUR 811 Million Second Track will upgrade the line from a single track to a double-track. The new line will run through 8 tunnels totaling 20.5 km in length. With service tunnels and exits the total tunnel network will be 37.4 km.

Excavated by New Austrian Tunnelling Method, the tunnels required a sprayed concrete (shotcrete) temporary lining for ground support with a performance specification of 320 Joules at 7 days and 400 Joules at 28 days according to ASTM C1550 panel testing. In total, 6 suppliers submitted fibres for performance testing. A detailed testing program was developed, beginning with cast samples in the laboratory followed by two rounds of onsite testing using sprayed samples of fibre reinforced shotcrete. BarChip54 and BarChipR65 passes all three stages of testing with convincing results and were subsequently specified for the tunnel shotcrete lining.

BarChip54 and BarChipR65 were used across all 8 tunnels of the Second Track, with over 850 tonnes used to reinforce more than 150,000 m3 of fibre reinforced shotcrete. Quality assurance testing was carried out each month and both Barchip 54 and Barchip R65 fibres delivered consistent, repeatable results in compliance with the contract specifications.