Salini Impregilo-NRW has reached a significant milestone for the Forrestfield-Airport Link, finishing the production of the concrete segments that line the walls of the tunnels – a total of 9098 rings (54,588 segments).
A purpose-built factory was established for the project, with a concrete batching plant, a carousel line and a steam curing chamber operated by concrete supplier Boral Ltd.
A world-class operation, the factory has set the standard for tunnel construction in Australia. The segment moulds were designed specifically for the project. Each segment has a double gasket, is water tight and has a durability of 120 years. The concrete mix was formulated according to specification, incorporating steel and polypropylene fibres to enhance strength and fire resistance. Close attention was given to the environment. In the formulation of the concrete mix, 20% of the steel fibres came from recycled material. After the production of each segment, the concrete waste material from the wet and dry concrete bins was converted into road-base or drainage rock.