Bamtec Steel Floor Slab Reduces the Concrete Reinforcement Required at Forth Valley Hospital by 190 Tonnes

The new Forth Valley Royal Hospital, commissioned by Forth Valley NHS, will serve a population of 300,000 and will be supported by a network of community hospitals in Stirling, Falkirk, Bo’ness and Clackmannanshire. The hospital opens in three main phases and, when fully operation in July 2011, will provide 860 in-patient beds as well as A&E, out-patient, day surgery, diagnostic and therapy services

One of the largest concrete frame structures in the UK, the Forth Valley Royal Hospital, was completed on time with the aid of Bamtec, an off-site fabricated steel carpet of floor slab reinforcement. The use of this reinforcement system also significantly reduced the steel required and in direct consequence the carbon footprint of the project.

Bamtec is manufactured exclusively by steel reinforcement specialist Hy-Ten in the UK. The construction programme had a tight window for the completion and Hy-Ten were approached to see if the Bamtec system could speed site placement of reinforcing steel in the floor slabs.

By use of finite element analysis to determine the stress loading within the floor slab, the Bamtec system can more closely specify reinforcement requirements leading to steel savings and still achieve the engineer’s exact needs. Design data is ported directly to robot welding machines that position and spot weld each reinforcing bar onto steel tapes to create a carpet with each bar precisely located. Reinforcement carpets are then rolled out on-site to create the required steel reinforcement mat.

Using Bamtec reduced the reinforcement required at the Forth Valley Hospital by 190 tonnes. There were direct cost savings, but more significantly around two tonnes of carbon dioxide are saved for each ton of steel eliminated. Further carbon savings arose from not having to carry this material to site.

Contractors using Bamtec report that they have been able to save up to one week per floor in build time. This was certainly the case at Forth Valley, where the teams were able to install the steel reinforcement, to a very complex floor plan, far more rapidly than with manual bar placement. Around 1000 tonnes of steel was used in this project. “During the most intensive phase, one truck per day left the Bootle factory with 28 tonnes of engineered reinforcement,” explained Hy-Ten director Richard Webster.

Hy-Ten has gained vast experience in resolving site problems over the ten years they have been supplying Bamtec in the UK. To benefit construction the use of pre-cast columns was favoured in place of conventional in-situ cast columns. Re-bars cast into the columns were bent at 90 degrees at the top of each column to lock into the floor slab. This created potential problems with the laying of the rebar carpets over the columns. Hy-Ten overcame this problem with the use of fabricated ramps. These allowed the carpets to be fully rolled out over the protruding column reinforcement. Once the carpet was placed, the mat around the columns could be easily completed with the addition of a small number of loose bars.