The new £45M campus for Queen Margaret University, Edinburgh, now rapidly taking shape south east of the city by the A1 in Musselburgh will stand as proud testament to concrete's aesthetic qualities.
When the building is complete, many of the columns and softs in the massive 150m by 75m four storey concrete structure will be exposed for all 4,500 students and staff to see.
Although the columns comprise 13,000m 3 of plain and simple C32/40 concrete with a BS8110 'Type B' plywood formwork finish, building the concrete superstructure has presented some technical challenges to the design and build team.
'Concrete by its nature wants to shrink and it is notoriously difficult to predict how it is going to behave when poured, ' says Neil Dely, associate with scheme designer Buro Happold. Design and build contractor is Carillion, and Expanded Structures is pouring the concrete as specialist subcontractor.
Preventing the concrete softs from cracking and ruining the building's internal appearance called for some crafty design.
The slabs are 250mm thick, increasing to 350mm in the teaching areas where the spans are larger.
'Because of the nature of the material there are always going to be cracks, but we couldn't cover anything up, ' says Dely.
'So we thought carefully about cores and restraint.' 'Putting in cores is the most economic way to bring in stability but they are stiff elements. So we had to think about where we put them and where we put restraint.' The building is so vast that it is split up into a number of discrete and individually stable units separated by movement joints. 'But on any typical floor plate where you put the cores is always a case of conicting interests. Putting them in the middle is good for shrinkage but for stability you want them near the outer limbs.
'What we've done is put them near the outer limbs but removed elements that would cause significant restraint.' Putting the design into practice also called for some skilful construction so that the best quality finishes could be achieved without using the most expensive, highest quality concrete mix.
Best quality concrete nishes usually have an increased quantity of cement in the mix.
But not at QMU. 'This is a perfectly standard concrete mix, ' says Dely, adding that even the shuttering is standard. 'Some columns are steel shuttered for maximum reuse of materials, but you can't afford to do that for the softs. We have just got a high quality plywood.
'I think it is all about attitude. If the contractor actually wants to do a good finish, you have got a far better chance of getting one, ' says Dely. 'It's about having pride in your work.' And pride there must be, because with the main structure now virtually complete it remains free from unsightly cracks, says Dely. Attention is now focused on fit out with the campus due for completion in time for the next academic year, beginning in October.
Client: Queen Margaret University Client's nancial partner: Barclays Design & Build contractor: Carillion Architect: Dyer Architects Designer: Buro Happold Concrete subcontractor: Expanded Structures Cost Consultant: Cyril Sweett Project manager: Heery Building services engineer: KJ Tait
Sustainable construction in action
QMU's new building aims to maximise sustainability. Even before completion it has been named winner of the 2006 Concrete Centre Award for Sustainability. The structure features a raft of innovations aimed at minimising its environmental impact.
A key element is the use of thermal mass and natural ventilation to minimise summer and winter energy use. As the concrete soft and columns are exposed there has been a substantial saving in ceiling materials and installation costs as well as a simplication in the electrical services installation.
The energy to operate the building will come from a combined heat and power plant burning biomass from local forests. In addition, the campus features a sustainable urban drainage system (SUDS) in the form of a pond to capture rainwater runoff from roofs and paved areas.
'Scotland is probably ahead of the rest of the UK in terms of SUDS, ' explains Dely. It's more out of necessity than anything else - particularly in urban areas the drainage system cannot cope so often it is a requirement that a scheme put no more surface water into the sewers than a 'green eld equivalent'.' Carillion prepared a site-specic environmental plan for the project that incorporates a waste management plan. All site waste is segregated and removed to a recycling centre run by Virridor, Carillion's waste management partner. Stringent heath and safety and environmental audits are carried out as well as recording wastes against the targets set. Every contractor on site is set a waste and a recycling target.
The scheme was also designed to balance cut and ll, so that no material is exported off site.
In use vehicle access to the site will be controlled, with internal circulation routes prioritised for pedestrians and cyclists.