Burgerweeshuis Amsterdam [Amsterdam Orphanage]
Health and social services / orphanage
Culture/leisure/tourism / art centre
Aldo van Eyck, Hannie van Eyck
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 .
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.
PRECAST ON SITE:
In larger and more complex construction projects, a concrete production plant may be installed on the construction site or nearby. The precast elements are moved into place once they have reached their maximum strength. This reduces transportation costs and ensures the concrete will set in the same environmental conditions as the building site. This may be more necessary with structures that combine cast-in-place concrete with prefabricated elements.
PRECAST IN FACTORY, WORKSHOP:
Any concrete element can be manufactured ahead of time and transported to the site once it has set. In this case, the control over geometry, appearance, finish and strength can be as strict as necessary. It can also be ensured that the pieces will be exactly identical to one another.
Prefabricated elements can be of any type: from façade panels and pavements to decorative elements (such as cornices or capitals) and structural elements (columns, slabs, beams, etc.).
These elements may be part of a commercial catalog or specially designed for a specific project. A series of pieces may also be sold as a coordinated and interconnected system to build a complete structure or even an entire building.
In its design, the element should account for aspects such as modulation, finishes, transportation, anchoring, installation on site, junctions between panels, the creation of openings and the relationship between the panels and joinery. The element may also be given characteristics that can improve the thermal insulation of the façade, for example. In that sense, they are often part of an industrialized system that offers a variety of responses to different construction situations and maximum versatility in terms of architectural solutions.
The aesthetic possibilities of concrete in prefabricated façade panel systems are endless in terms of size, shape, color, texture, hardness and a wide range of features.
Beams are the horizontal load-bearing elements of the frame. Columns are the vertical elements of the frame and act as the building’s primary load-bearing element. They transmit the beam loads down to the foundations.
State of Conservation
There were two principles that inspired Aldo van Eyck in the construction of this orphanage with room for 125 children. On the one hand, an abundance of interior and exterior spaces are alternated to create complexity and variability in the architecture, to make it easier for the children to make themselves at home in a building that was, to a large extent, their world. On the other hand, the building was meant to dissolve its boundaries with the city, to become open and inclusive: just the opposite of the isolated spaces associated with orphanages of the past in the collective consciousness.
The resulting building feels more like a labyrinth or a casbah, where interior and exterior spaces alternate and blend together almost imperceptibly. This is achieved through the repetition in plan of a square module measuring 3.40 meters per side. A total of 336 of these small modules are added together following a pattern of organic growth that spreads out in centrifugal wings, generating courtyards that are either closed or open at one of the corners.
Each of the modules is covered with a prefabricated concrete circular dome that rests directly on a series of beams; in turn, the beams are supported by circular pillars, all built in reinforced concrete. Occasionally, for certain unique spaces, nine modules are combined together and covered with a larger dome, but with a similar circular section. On the façades, prefabricated concrete panels are alternated with ceramic or glass bricks. Concrete is present in the interior as well, beyond the structural elements, in the pavement finishes and in multiple built-in furnishings, such as benches or seating areas.
North Holland 1076 CV Amsterdam
Fundación DOCOMOMO Ibérico