So when a device was invented that could remove this risk for labourers when they are splicing rebar cages for large diameter piles, it was perhaps unsurprising that it was lauded as NCE’s Star Choice safety product this summer.
Geotechnical product manufacturer Romtech’s Safe Splice removes the traditional dangers of splicing together two vertically overlapping rebar cages by getting rid of U-bolts. If U-bolts, also known as bulldog grips, are used to lock the two cages together, workers must use their hands to ensure the cages are successfully spliced. This carries the inherent risk that they will get their hands trapped as the top cage is lowered onto the bottom cage.
“Bulldog grips are made for wire rope, not rebar,” explains Romtech technical director Steve Render.
“When you start examining things like putting hands in cages it is really a no-brainer that things need to change.”
In contrast to the use of U-bolts, the Safe Splice system allows workers to stand away from the cages as they are spliced. Sets of plates are welded to the outside of each end of the cages at the point where they will be spliced, and are used to help guide them into position as they are lowered. This means that workers only have to touch the outside of the cages as they assist the positioning process.
The plates contain threaded holes and, once in position, are bolted together to make the splice.
As an additional safety measure, a steel band is welded into the top cage below the splice point to be used as a support when splicing takes place. The band rests on steel bars placed across the pile sleeve, while the plates on the bottom and top cages are bolted together.
Safe Splice has so far been used on three major construction projects. First was the widening of the M1 between its junctions with the M25 and Luton Airport, where it was used on all piles for bridge abutments. It was then used on the contract for the widening of the M6 between Carlisle and Guardsmill. On each of these schemes, Safe Splice was applied to roughly 1,000t of rebar cage.
Now, in its third and largest project, Safe Splice is being used with 2,000t of rebar for the foundations of One New Change in London, on a site adjacent to St. Paul’s cathedral.
Developed by Land Securities and designed by architect Jean Nouvel, One New Change is a £500M retail and office development that aims to become the major shopping destination within the square mile of the London. Main contractor is McGee (News last week).
Safe Splice is currently being used by geotechnical contractor Cementation to retain wall piles for the development’s underground car park.
It will be subsequently applied to all load bearing piles on the project.
“We always want to improve safety and streamline the construction process, and Safe Splice is something that helps us do both,” says Cementation project director Ian Lovett.