Original name
Aula Congress Center, Technische Universiteit Delft (TU Delft)
Other denominations
Aula Technical University, Building 20
Original use
Education, Center for higher education / conference and congress hall
Current use
Education, Center for higher education / conference and congress hall
Architects
Johannes van den Broek and Jaap Bakema (Van den Broek en Bakema)
Concrete by reinforcement
Concrete is a relatively brittle material that is strong in compression but less so in tension.
To increase its overall strength, steel rods, wires, mesh or cables may be embedded in concrete before it sets. This reinforcement, often known as rebar, resists tensile forces. By forming a strong bond, the two materials are able to resist a variety of applied forces, effectively acting as a single structural element .
Prestressing is a method that helps increase the strength of reinforced concrete, specifically making it possible to increase the distances between supports. As such, it is very common in bridge construction and for creating large spans without intermediate supports.
These long spans are achieved by subjecting the structural elements to compressive forces in an initial resting position, prior to their use in construction. Once the elements are subject to loading, their capacity to withstand axial tensile stresses is increased and their structural behavior is substantially improved.
Prestress — (1) to place a hardened concrete element or an assembly of units in a state of compression before the application of service loads; (2) the stress developed by prestressing, such as by pre-tensioning or post-tensioning.
Pre-tensioning — method of prestressing reinforced concrete in which prestressing steel is tensioned before the concrete is placed.
Post-tensioning — method of prestressing reinforced concrete in which tendons are tensioned after the concrete has attained a specified minimum strength or a specified minimum age.
Construction method
In this case, the concrete can be made by mixing the components directly on site, or it may be transported from a production plant in concrete-mixer trucks.
This method has the disadvantage of leaving the concrete exposed to the elements while it is setting. Whereas, with other methods, the environmental conditions can be controlled during setting, providing greater control over the outcome, with cast-in-place concrete a series of tests and protocols are necessary to verify its final strength.
Architectural concrete
- textured walls
- wooden formwork finish
- stamped concrete
- exposed aggregate concrete, colored concrete, etc.
Structural types
A series of arches are situated parallel to one another at a distance that allows for covering them with smaller secondary structures such as beams or plates. This type of structure also calls for support elements perpendicular to the arches to avoid the “domino” effect .
The construction of cantilevers creates structures that protrude from their supports without external reinforcements, contrasted with constructions supported at both ends, where the load is distributed between them, like in the case of a beam or a lintel. Formal strategies can be used to improve the structural performance of the cantilever and reduce thicknesses.
A suspended roof refers to the case where the vertical supports do not rest on the ground but hang from a structure above. Steel cables are often used for these supports, since they are only subject to traction forces.
State of Conservation
Description
The Brutalist architecture by the team of Van den Broek & Bakema had a remarkable influence on the Dutch architecture boom, led by Rem Koolhaas, at the end of the 20th century. One of the hallmarks of that movement, drawing on the architecture by Van den Broek & Bakema, were buildings that could express the functions they housed inside through their exterior volumes. Expressing the building’s section on the façade was the fundamental mechanism for the architectural definition of a building. The conference centre on the TU Delft campus clearly embodies this principle and, to achieve this, its authors take full advantage of the formal and structural capabilities of reinforced concrete.
The building, now an emblem of the campus, takes advantage of the sloping section of the auditoriums and classrooms to generate a bowl-shaped exterior volume, creating futuristic lines that have earned it the nickname of “UFO”. The entry points are protected and highlighted by the large sloping concrete surfaces, such that the floor plan on the ground level is smaller in area than the floors above it. A continuous exposed concrete structure – which is both the volume and the structure of the building – is combined, on the roof, with folded concrete surfaces that provide the necessary rigidity to span the large rooms without intermediate supports.
Van den Broek & Bakema played a key role in the post-war reconstruction and urban transformation process in the Netherlands. Like in other European countries, Brutalist concrete architecture – as well as the trend towards integrating architecture and urban planning – were essential aspects of that process.
Netherlands
Mekelweg 5
South Holland 2628 CN Delft
Commission
1959
Completion
1966