trusses at 8.175m . Lattice girders provide support for the internal trusses to ensure a 1,000m 2 column free grid . Tilt-up construction was used for the concrete columns and perimeter concrete walls . The steel roofs are curved not only for aesthetics but also to reduce cost . A cost saving was possible due to the reduced wind load exerted on curved roofs which reduced the overall cost of the structural system . The curved shape is structurally more efficient than a conventional boxed warehouse structure .
The Dry Goods warehouse has the highest apex of 25m and is the biggest warehouse at the Pick n Pay site of 279m x 411m long .
Tilt-up Panel Construction A pre-cast concrete tilt-up system was used to construct the warehouse columns and perimeter walls . The concrete walls and columns were cast on top of sacrificial surface beds and once cured were lifted into position with a mobile crane .
Tilt-up construction simplifies the construction of tall concrete columns and large wall panels . The concrete quality is generally also better as most of the work can be done at ground level and columns can be cast in one pour . Most of the concrete wall panels were 150mm thick and five or six panels were cast on top of each other . The tallest columns cast were 26.5m which would have been difficult if conventional methods were used .
A concrete dividing wall was constructed between the Dry Goods and Perishables warehouses . This wall was 200mm thick , 26.5m high at the apex and designed to be 2-hr fire rated . Tilt-up walls were also used for this dividing wall as conventional brickwork would have been time consuming and it would have been difficult to achieve a high-quality finish .
Warehouse Floor A warehouse floor is one of the most critical structural elements that not only supports the racking system but also determines how effectively forklifts and reach trucks can operate . Joints in floors are considered to be the weakness of any floor and deterioration often starts at the joints . Floor joints should be limited to reduce maintenance and damage to wheels . For the Pick n Pay site the floor should also be able to span across a 5m sinkhole which eliminated the use of a conventional saw-cut floor . Post-tensioned and fibre reinforced floors were designed to reduce maintenance costs and operational down time .
38 Pick n Pay