Under a four million pound contract, Hy-Ten has supplied reinforcement for the concrete aprons that form the basis of the new building.The T2 building is one of the largest construction projects in the UK and certainly the most time critical. Being the world鈥檚 busiest international airport Heathrow has an urgent need to expand and upgrade passenger facilities.聽聽聽
Two 1.2 metre deep concrete aprons, each with an area of 45,000 square metres, form the main structure.聽 These required 8,000 tonnes of steel reinforcement bar.聽 Conventionally, this would all be placed by hand with each bar being manually wired into position, a time consuming and slow process.聽 Given the complexity and time-critical nature of the project the Bamtec rollout steel reinforcement system offered an opportunity to advance the programme.
The Bamtec system eliminates time consuming on-site back breaking manual bar placement.聽 Instead, in a quality controlled factory environment, reinforcement bars of the correct specification are pre-positioned by robotic spot welding machines into steel tapes.聽 This creates a carpet of reinforcement.聽 Each carpet is tagged, numbered and colour coded for easy positioning and rollout on site.聽 This allows the steel fixing in a fraction of the time usually needed.聽 Site labour demands are greatly reduced and the factory assembled system also provides greater quality assurance.聽 Contractors using Bamtec are also more able to complete significant parts of the programme within the available weather windows.
To demonstrate the speed and viability of the process to the contractors Laing O鈥橰ourke, Hy-Ten created a full depth, partial mock-up of the concrete slab reinforcement at their Liverpool works.聽 This proved the speed with which the twin steel reinforcement layers could be positioned for the upper and lower zones of the floor slab.聽
Deep steel chairs were required to separate the upper and lower reinforcing layers in the deep slabs.聽 Hy-Ten 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.聽 This device has now been patented and forms part of the Bamtec installation process.
Work on the aprons began in May 2010 and was completed in Spring 2011.聽 Hy-Ten shipped up to 250 tonnes of steel reinforcement per week to the site with all deliveries precisely scheduled to meet the just-in-time steel placement programme.聽 鈥淭here have been 72 concrete pours for 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,鈥� commented Hy-Ten director Richard Webster.
鈥淭his is a large scale and complex project taking place in the middle of a major international airport.聽 In addition to meeting the needs of Laing O鈥橰ourke, Hy-ten have had to work within time access constraints imposed by the airport operator and meet stringent security criteria.聽 We have met this challenge fully and helped keep our customer on track for this phase of the project,鈥� commented Richard Webster.
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