Construction of the express road S7
CRH companies in Poland have joined efforts to design a unique and innovative offer for the construction of the express road S7 “Zakopianka”, its bridges and its two tunnels – the longest ones in Poland
The technologists of Bosta Beton (Rmx), Trzuskawica (Aggregates & Lime) Grupa Ożarów (Cement) have joined efforts to design recipes of a frost-proof ready-mixed concrete resistant above 50 MPa, and of a sprayed concrete (‘shotcrete’). Because of the technology chosen for the construction of the tunnel, shotcrete is a crucial part of the whole process. In the course of tunnel drilling, the walls and vaults are protected by a temporary housing from sprayed concrete and then, after drilling consecutive 70-80 m segments a permanent housing of high-strength C50/60 concrete is formed by a special formwork.