Prefabrication experiments - 314 - Icons - 04 - Richard's Medical Centre by Louis Kahn

 

Orchestrating the relationship between form, function, structure, envelope and mechanical devices is one of architectural modernity's most important legacies. The methodical division of an edifice into clearly identifiable elements, components, sub-assemblies and their subsequent layering into hierarchies influenced and outlined industrialized building principles as an efficient way forward for construction. Within this notable spectrum of ideas, a tenet stands out as the union of systems theory and dimensional coordination, both epitomized modernism at the beginning of the 20th century: the clear separation of served and service spaces. Served spaces are the main living / working areas, inhabited freely, while service spaces refer to networks and areas labelled for circulation, mechanical systems or other supporting elements. 

 

Louis Kahn is recognized for his masterful harmonic arrangements of served and service spaces. From Kahn’s work, a collaboration with structural engineer August Komendant for the Richard’s Medical Centre building in Philadelphia built 1957-61 for the University of Pennsylvania exemplifies these fundamental organizing principles. The Structural frame is marked by the distinction of service and served spaces as floorplates are treated as a thick open web «service» slabs assembled from precast and prestressed concrete components. Typically spanning 45ft x 45ft (13,7m x 13,7m) the mega concrete space frames are composed of Vierendeeltruss like elements. Each square tower’s two-way floor structures are supported by eight perimeter columns placed on a 15-foot (4,5 m) grid at the midpoint of each floor edge freeing cantilevered corner angles. From and aligned with the exoskeletal columns, four principal truss beams form a central crisscross pattern and support outrigged perimeter beams that bound the floor plate. Other secondary truss elements infill the thick slab's grid. All spans are regulated by a strict 7,5 foot (2,25 m) planning grid.  The Floor plate voids are connected to vertical service towers used for mechanical distribution and circulation.  The reinforced precast concrete elements were assembled on-site; Each joint's rebar extended and then mortared to achieve a complete monolithic structure. Representative of Louis Kahn's didactic language, the building's section is equally clear as each floor connects to and relates to vertical service tubes by becoming a type of open duct to serve the free-flowing space's above them. 

Floor plate structural diagram