Milan | Faculty Building | Grafton Architects

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Gateway to education

4 September, 2009

By Graham Bizley

Irish practice Grafton Architects has created an impressive new faculty building that also acts as a front door to Milan’s Bocconi University

The Bocconi University campus lies just to the south of Milan’s city centre where the grain of dense, tightly defined streets starts to break down into a looser landscape of detached buildings and open spaces. At the north-west corner of the campus, closest to the city centre, Dublin-based Grafton Architects has made an emphatically urban statement with a new building that acts as a front door for the university complex.



Entrance elevation at via Bligny and via Roentgen where the buildings are set back to form a long piazza.

The entire structure is concrete — over 80,000 cubic metres of it — enabling the volume to fracture and rise in a shifting composition of cantilevering forms. The exterior is dressed with Ceppo di Gré stone, a grey marble from Lombardy which has also been used for the surrounding pavements.
Occupying a 160 x 80m, site the new additions house all the university’s faculty staff offices and research institutes. Grafton won the commission in an invited competition in 2002 and it was complete in time for the beginning of the 2008-9 academic year.
Despite its scale and apparent complexity, the organisation is remarkably simple. The entrance midway along the west elevation opens into an internal public space inspired by the broletto, a typical northern Italian civic building usually housing the town hall with an open colonnade market place beneath. Grafton Architects’ director Shelley McNamara describes the space as “a place of exchange, a filter between the university and the city”.



Office levels are interspersed with glazing that draws light deep into the building.

Above the ground floor space five floors of offices are suspended from giant 24m-long concrete roof beams. Clad with glass and interspersed with light wells, the bars of offices form a grand canopy over the ground-floor space allowing natural light to filter down deep into the plan.
At the most prominent corner of the site at the intersection of via Bligny and via Roentgen the buildings are set back to form a long piazza that gradually becomes more enclosed by the volumes above as you move towards the entrance. A 1,000-seat Aula Magna (great hall in Latin) has been placed nearest the corner, “like an embedded boulder” as McNamara describes it. Facing via Bligny the wall comes right down to the pavement but on the eastern side the rake of the hall rises up to partially shelter the piazza. A magnificent 6.7m high glass wall allows passers-by a view down on the subterranean foyer to the hall and gives the university a window on the city.
The remarkable presence and sculptural quality comes from the absence of vertical supports. The building is divided into five 24m clear-span bays with 3.4m structural and circulation zones in between. The structural zones are defined on the lower levels by “septums”, 1.2m-thick concrete fin-walls spaced 8m apart to support the circulation zones above. Pre-stressed concrete was used for the below ground floor slabs to achieve the long spans.



Main concrete staircase

Three different structural solutions were used above ground. The Aula Magna lecture hall is supported on four 400mm-thick concrete wall-beams which rise 40m above the raft. The lateral concrete walls act as deep beams spanning in between.
For the internal office zone the architectural idea demanded that the great blocks hang over the ground floor space. The office floors are therefore suspended on steel tension cables at 3.4m centres from 3.4m-deep concrete roof beams. To provide fire protection the cables are sheathed in a fire-resistant tube while an outer 130mm-diameter steel tube with an intumescent paint finish provides a decorative casing.
The most complex structural solution was required for the volumes that cantilever out along via Roentgen. By making the different elements counter-balance one another and work together the depth of the concrete floors was kept down to 400mm and the 24m span beams are only 600mm deep.
Self-compacting concrete (SCC) has been used extensively for the wall-beams, septums, roof beams and Aula Magna roof structure where quality is vital, either for visual reasons or where the structure is particularly complex.
For the concrete supplier the project provided an opportunity to research the relationships between the concrete mix, delivery regime, pouring technique and quality control of SCC. The architects demanded a fair face devoid of air bubbles where the concrete would be visible. Forty two different mixes were tested and a pouring technique was developed using a funnel pipe which delivers the concrete direct to the bottom of the formwork, preventing splashing which would incorporate air bubbles and allowing the start of each pour to be uniform.
The consistency of every single mixer of concrete was tested on arrival on site. As the work progressed the workability time was increased from 90 to 120 minutes and the acceptance limits of the flow-table test were halved to 100mm in a range of 700-800mm to ensure the desired quality was achieved throughout.
This is a building that could not have been built in any other way. The plastic qualities of concrete have given the university a new symbolic presence in the city, a fusion of permanence, movement and openness.

PROJECT TEAM

Architect: Grafton Architects, Client: Universita Luigi Bocconi, Structural engineer: Studio Ingegneria E.Pereira,Services engineer: Amman Progetti, Main contractor: G.D.M. Costruzioni S.p.a. Concrete supplier: Unical, Stone cladding: Marini Marmi s.r.l.

Fonte: World Architecture News