The firm is employing a never-before-used technique to upgrade an outdated shopping centre. Damon Schünmann went to have a look.
Project: The Beacon (formerly the Arndale Centre)
Client: Legal & General
Overall redevelopment value: £85m
Contract value: £50m
Contract type: JCT Design and build
Main contractor: Kier
Steelwork subcontractor: Caunton Engineering
Concrete subcontractor: Freyssinet
Demolition subcontractor: Best Demolition
Start date: January 2017
Completion date: November 2018
Eastbourne’s Arndale was completed in 1979, and it looks it.
“It’s old and dated,” says Kier senior project manager Alan Quigley. “[The town] has been trying to get an upgrade for 20-odd years as no-one shops in Eastbourne; they go to Tunbridge Wells or Brighton.”
But an upgrade it is now getting. You can’t make an omelette without breaking a few eggs goes the saying, and a series of houses and a pub that stood in the way have been demolished via compulsory purchase orders, lying as they did on the adjacent Terminus Road that runs north-west from the promenade, up past the shopping centre and continuing to the nearby station.
The shopping centre’s £85m expansion will comprise the construction of a three-storey extension to provide 175,000 sq ft of retail and leisure space. This will allow for about 25 shops and seven restaurants, as well as an eight-screen cinema on the roof.
Alongside this will be another two decks of steel-framed car park built on top of the existing – and in-use – reinforced concrete-frame multi-storey, to cater for the anticipated increase in footfall to the revamped ‘Beacon’ shopping centre.
It’s on the car park that Kier is using a technique never before used.
“Possibly the most innovative part of what we’re doing is that the existing structure cannot carry the load of the concrete decks or the car park,” Mr Quigley says.
“The existing RC frame columns are extremely slender and they can’t carry the load of even the concrete decking, let alone the vehicles”
Alan Quigley, Kier
Faced with this challenge, Kier opted for a new column strengthening system that avoids replacing the original structural support.
“The existing RC frame columns are extremely slender and they can’t carry the load of even the concrete decking, let alone the vehicles,” Mr Quigley explains.
“We have a product called an Exoleaf, that is patent pending and has never been used before. It’s an ultra-high-strength metal fibre reinforced concrete jacket that’s pre-formed offsite with 150 kN compressive strength.”
This sees U-shape jackets produced by Freyssinet – a subsidiary of French firm Soletanche – attached either side of the old columns and clamped together. Operatives then fill any voids between the new and the old with high-pressure grout, injected from the bottom of the jacket upwards.
“Once it goes around the [existing] columns, [those] old columns are redundant because this carries five times as much load,” Mr Quigley says. “A similar system was used on another project of ours at Gatwick, but this is a [further] development coming off the back of that.”
The project took a while to get off the ground with various elements in flux before the deal was inked. “We were negotiating this contract from the back-end of 2015,” Mr Quigley says, adding that with things “chopping and changing”, Kier didn’t formally win the work until almost the end of 2016.
With terms and conditions agreed, demolition work began in January 2017. “We had expected asbestos in the buildings along Terminus Road and that was taken within the contract sum,” Mr Quigley says.
“There has been additional asbestos found at various locations,” he says, adding that this required over £750,000-worth of remediation beyond what had been expected. “Most of what we found was chrysotile, but also some amosite sandwiched in-between slabs. There’s been an awful lot of work to [remove] that.”
The difference between the Gatwick car park project and the one used at Eastbourne is that the former used a corbel detail that just clamped around the top of a column; it didn’t include the use of the ultra-high performance concrete.
Kier Arndale Shopping Centre 4
Not every column will be getting a jacket, but the car park will feature 87 by the time the job completes.
The car park is due to open alongside the centre in November.
Hippos and bombs
“We’ve had to have archaeology on the project,” he says, explaining that when the centre was first built, it led to the unearthing of an ancient hippopotamus. Nothing hippo-related came to light this time around.
The job also involved a watching brief for unexploded ordnance (UXO) and pile probing for munitions. “Believe it or not, Eastbourne was the most bombed coast on the south coast in the Second World War,” Mr Quigley says. “More than Portsmouth, Southampton or Plymouth. I think this was on the flight path home and if they had anything left they just dropped them.”
Prehistoric remains and UXO aside, the ground still threw up its fair share of surprises. “We had soft spots [and also] an unbelievable amount of unrecorded services, even though we’ve got full ground penetration surveys,” Mr Quigley says.
“There was some expectation of finding a body because there was a fellow that went missing from the Gildredge Pub”
Alan Quigley, Kier
“There was some expectation of finding a body because there was a fellow that went missing from the Gildredge Pub [demolished as part of the job], but that’s the one thing we didn’t find,” explaining that the team had to contend with multiple basements from buildings that were previously at the site.
“It took a long time: there were 23 delay events, all of which we subsumed into the contract period and there’s been no change to the end date of the project,” Mr Quigley says, before pointing out that working extended hours was just part of the solution.
With this amount of disruption, the construction plan required an overhaul. The result saw piling and demolition, ground beam installation and steel frame erection all happening concurrently on what is clearly a very tight site.
Kier Arndale Shopping Centre 6
It also meant concrete pours for floors had to happen before drainage had gone in, which Mr Quigley acknowledges was not ideal, but allowed the steel frame to progress. “The frame was almost completely fabricated and we didn’t want to be paying time for it to be laying down in their [Caunton Engineering’s] yard,” he says.
“The frame was almost completely fabricated and we didn’t want to be paying time for it to be laying down in their [Caunton Engineering’s] yard,” he says.
On top of the retail space, the cinema and the car park, Kier is reconstructing the east entrance to the Arndale centre, having previously completed the same job on the west entrance in 2016.
“We’re upgrading from a very old 1970s-style external façade in a live environment with 20,000 footfall per day coming through there. We’re having to close off half of it at a time so that we can change the shop fronts and put a new glass atrium box up to improve the visage,” Mr Quigley says.
At about 2,500 tonnes of steel for the extension and the additional car park floors, the cost could have been considerable.
This concurrent activity made for a busy footprint, with 17 machines on the project at one point ranging from a 45-tonne long-reach demolition ‘muncher’ through to dumpers.
“There’s no fixed tower crane because [the site is] too spread out, so we’ve got mobile tower cranes and as part of the time recovery we’re putting in two [of them] into the mall area at the same time, where it should have been one,” Mr Quigley says.
“The problem with that is it sterilises the area of works in the mall, which are critical to the opening as they’re taking up the footprint that we need to work in. One will be working on the south side and one on the north.”
Building yourself into a corner
Critical to the programme is that the principal two store units being built have the earliest handover and these will incur ‘damages’ if they are not handed over on time. Added to this, they have the lengthiest fit-out periods and this dictated Kier’s point of commencement on the site.
“In an ideal world I’d have built out [from the existing building towards the edge of the site] because then I wouldn’t be constraining and building myself into a corner where I’m up against the [original] building,” Mr Quigley says.
“The way I would have chosen to do it has been flipped on its head, especially with things like the [new] glass undulating roof [of the extension], I’m starting at the wrong end. I’ve closed myself into the corner where I’ve got to get the last panels in and I’m up against the building.”
But he’s phlegmatic on the impact of such things. “They’re logistical things that any job has,” he says.
Kier Arndale Shopping Centre 2
It’s a testament to the flexibility of a modern construction programme, and the will to get the job done on time, that the delivery of The Beacon remains on track.
And it’s a construction programme that, when completed, should see Eastbourne residents shopping closer to home once the project completes in November.