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Bootle, Merseyside, United Kingdom, 2011/03/16 - Under a four million pound contract, Hy-Ten has supplied rollout reinforcement for the concrete aprons that form the structural core of the new Heathrow T2 building.
Main contractors Laing O’Rourke and engineers HETCo turned to Hy-Ten, suppliers of the Bamtec steel reinforcement system to buy time in the delivery of the project.
One of the largest construction projects in the UK, and certainly the most time critical, the new Heathrow T2 is crucial to further development at the world’s busiest international airport. Growth in air traffic has created an urgent need to expand and upgrade passenger facilities as quickly as possible.
To demonstrate the speed and viability of the process to the concrete frame contractor Laing O’Rourke, Hy-Ten created a full depth, partial mock-up of the concrete slab reinforcement. This proved the speed with which the twin steel reinforcement layers could be positioned prior to concrete pouring.
Bamtec eliminates time consuming and back breaking manual bar placement. In a quality controlled factory environment, reinforcement bars of the correct diameter and length are pre-positioned according to the structural engineer’s specification, Robot spot-welding machines fix these onto steel tapes to create a carpet of reinforcement. Each carpet is tagged, numbered and colour coded for easy positioning and rollout on site. This allows the steel fixing in a fraction of the time usually needed. Site labour demands are greatly reduced and the factory assembled system also provides greater quality assurance. Contractors using Bamtec are also more able to complete significant parts of the programme within the available weather windows.
Deep steel chairs were required to separate the upper and lower reinforcing layers in the 1.2 metre deep slabs. Hy-Ten (hy-ten.co.uk) designed a bespoke roll-out device so that the upper layers of reinforcement could be placed by operators working at ground height, speeding the process and eliminating fall hazards. This device has now been patented and forms part of the Bamtec installation process.
There are two concrete aprons, each with an area of 45,000 square metres. These form the main structure and required 8,000 tonnes of steel reinforcement bar. Work on the aprons began in May 2010 and was completed in Spring 2011.
At the height of the programme, Hy-Ten shipped up to 250 tonnes of steel reinforcement per week to the site. All deliveries were precisely scheduled to meet the just-in-time steel placement programme. “There have been 72 concrete pours to make the lower apron and for each pour we estimate that we have been able to reduce the steel placement time by two days compared to conventional steel fixing,” commented Hy-Ten director Richard Webster.
“This is a large scale and complex project taking place in the middle of a major international airport. In addition to meeting our customers’ needs, Hy-ten have had to work within time access constraints imposed by BAA and meet stringent security criteria. We have met this challenge fully and helped keep Laing O’Rourke on track for this phase of the project,” commented Richard Webster.
Heathrow is the largest international airport in the world, measured by passenger numbers, with 67.7 million passengers per year. The old T2 was designed to handle 1.2 million passengers per year, but was handling eight million by the time of its closure in November 2009. The new facility will eventually increase T2 capacity to 30 million passengers per year.
The new T2 will be built in two phases. The first phase will be completed in 2013 and will provide a total area of 180,000 square metres. Phase two will be completed in 2019. The overall investment in T2 and facilities at the eastern end of the airport will be £2.2 billion. This is just part of an overall programme by BAA of investment in facilities at Heathrow that will total £4.8 billion.
HETCo is a Ferrovial Agroman and Laing O’Rourke joint venture. Primary architectural design for T2 was by Foster and Partners with HETCo developing the detailed proposal and engineering. Expanded Ltd, responsible for the concrete core of the building, is a subsidiary of Laing O’Rourke.
The new T2 will be the home to the Star Alliance Group, comprising 36 carriers, including majors such as bmi, United, Lufthansa and Singapore Airlines.