book-2

STRUCTURAL DETAILING 141▲ 7.18Precast bracket and frame junction.▲ 7.17 Ferry Terminal and office building,Hamburg, Germany, Alsop and Störmer,1993. Partially exposed precast concreteA-frames.concrete’s materiality can be expressed. These buildings are essays inthe architectural exploitation and expression of cast-in-place concreteas a structural material.The typical characteristics of precast concrete – thin and compactcross-sections, relatively complex forms and repetitive member layout –are exemplified in the Ferry Terminal and office building, Hamburg(Fig. 7.17). Thirty-three pairs of precast concrete A-frames define the200 m long building. Generally placed just inside the exterior skin oneach side of the building, each pair of frames supports simply-supportedbeams and suspended floor slabs that span between them.Several frame bases are exposed within the ferry terminal waitingroom.They support precast concrete cantilever brackets, similarlydetailed as the main frames, to extend the terminal area beyond themain building line (Fig. 7.18). Given their skeletal form, blue painted finishand smallness of cross-section, the brackets could actually be mistakenfor steel construction! The architect clearly articulates the pinconnections between the A-frames and their brackets, and thereforeemphasizes the site-jointed nature of the precast components. Both intheir forms and connections, the brackets and frames are consistentwith and expressive of the materiality of precast concrete.The final two examples where structural materiality and constructionare expressed clearly begin with the Guggenheim Museum, Bilbao. Justenough structure is exposed to explain the building’s construction