Concrete at the core of SAHMRI’s success

Its nickname is the ‘pine cone’ – a nod to its distinctive aluminium and steel dia-grid façade. But there’s much more to the South Australian Health and Medical Research Institute (SAHMRI) than meets the eye.

Opened at the end of 2013, SAHMRI is South Australia’s first independent flagship health and medical research institute, home to some 600 researchers.

The building’s external form rightfully attracts plenty of public attention, but the unsung hero underpinning the elegant design is concrete.

The concrete lift core is the building’s backbone, essentially holding everything up. The post-tensioned concrete floor slabs and beams all tie back to this core.

Even the sculptural flower columns, which effectively transfer the column loads of the upper levels to six points on the ground plaza level, rely on the lift core.

Although rendered in a concrete finish, these columns are actually structural steel. The ‘branches’ of each column meet the slab above at an angle, and therefore need to be supported laterally by the slab itself (which in turn is tied back to the lift core).

This sophisticated engineering solution allows the building to seemingly ‘float’ above the ground plane, without a forest of columns supporting it.

The inherent mass and energy absorbing qualities of concrete, coupled with its spanning abilities, was also key to controlling vibration – a critical challenge to be overcome in a research facility of this kind.

On the upper lab floors, vibration is effectively taken care of by the positioning of the columns on either side of the lab benches. The lab levels typically have 36 columns, with the loads transferred to the six points on the ground plaza level via the flower columns.

One of SAHMRI’s most significant areas of expertise and activity is in nuclear medicine. Deep in the bowels of the building is a cyclotron, a particle accelerator used to produce radioisotopes for cancer testing and treatment. To contain the radiation, the cyclotron is housed within an insitu concrete bunker - the walls, floor and roof of which are 1600mm thick.

Because the radioactivity only impacts on the first 100mm or so of wall depth, the internal walls of the bunker are lined with a sacrificial façade of purpose-manufactured concrete blocks. These can be removed and replaced at appropriate intervals to extend the overall life of the cyclotron.

The use of concrete to ‘do the heavy lifting’ in SAHMRI has allowed other materials to shine, and in particular realise one of the most important design objectives – to allow the building to proudly and openly tell its own story.

Anoop Menon of Woods Bagot says research laboratories are typically sterile, internally focussed spaces, with the external expression very much of secondary consideration.

“We wanted to turn that idea on its head,” he says.

“We wanted people walking past this building to look up and see the researchers working inside – and hopefully be inspired.

“So, the fluidity of the building, the shapes, the transparent façade showing the internal atriums on either side… it’s all about attracting the eye and revealing and promoting what happens inside.”

While most of the concrete underpinning SAHMRI’s form and function is hidden from the eye, it does feature prominently in the ground-level internal plaza. Here, the structural concrete floor slab is finished with a 150mm topping slab, ground and polished to expose the aggregate.

The external plaza area also features a concrete slab with an acid-washed finish, while precast concrete planter boxes at the building entrance complement the surrounding forms and finishes.

The durability and strength of concrete was a key factor in its choice, particularly for the outside plaza area.

But the solidity of the concrete form, coupled with its finish, was also crucial to the overall aesthetic of the plaza level, inside and out, contrasting with the glass forms and the aluminium and steel façade.

“We tried to get the materials to talk to each other and symbolically merge,” says Menon.

“So even the concrete has fluidity of movement. The patterns on the surface reflect the dia-grid façade.”

Ultimately, the success of any public building is measured by its level of engagement with those who use it, the physical environment around it, and the community at large.

It’s a testament to this remarkable building, and those who designed and built it, that its occupants describe it in glowing terms – and that more than four years after its opening, there is still a waiting list for public tours.