The Italian architect, engineer, and builder Pier Luigi Nervi (1891-1979) was one of the most inventive exploiters of reinforced-concrete construction of the 20th century.
Pier Luigi Nervi
Reinforced concrete, a material combining the monolithic compressive strength of concrete with the tensile strength of steel reinforcing rods, entered the history of architecture at the end of the 19th century in France. The earlier patented processes of Joseph Monier, François Coignet, and others were applied by François Hennebique at the Charles VI Mill at Tourcoing (1895) and by Anatole de Baudot in the church of St-Jean-de-Montmartre in Paris (1894-1897). Those were the first significant uses of reinforced concrete for large-scale architectural problems. Some later builders used reinforced concrete in traditional, linear ways; others recognized that the material could accommodate an experimental approach using continuous curving systems. Pier Luigi Nervi was a leader in the latter approach.
Born on June 21, 1891, in Sondrio, Italy, a town in the Alps, Nervi, the son of a postmaster, graduated from the School of Civil Engineering in Bologna in 1913. He gained practical training with building firms specializing in concrete construction, in Bologna before World War I and in Florence afterward.
In 1923 Nervi established his own firm in Rome. His first all-concrete building was a small cinema in Naples, built in 1927. He recalled later how skeptical architects were "sure my building would cave in for lack of proper support." In 1929 he produced a work of remarkable significance: the Municipal Stadium in Florence. An economical design, with a grandstand roof cantilevering some 55 feet and exterior stairs of cantilevered spirals, the stadium established Nervi's reputation.
In 1932, he formed a new firm, Nervi and Bartoli, and that company in 1936 developed a series of airplane hangars using reinforced concrete that was poured in place. Two hangars were built, but the difficulties of poured-in-place concrete construction led in 1939 to a second hangar design using precast concrete sections, a system Nervi used with great success after World War II. Six hangars of the second type were erected; Paul Goldberger of the New York Times described them as "graceful, flying forms of concrete." All eight hangars were dynamited by retreating German forces in 1944, and Nervi was so upset, one of his sons recalled, that "he wanted to crawl under those hangars and die with them."
Visions in Concrete
Nervi designed and built an exhibition hall, the Salone Agnelli, in Turin (1947-1949) using a system of prefabrication he developed. The structure is composed of precast sections of what Nervi called ferrocemento, a material made of a fine mesh of steel wire filled and covered by a thin layer of cement. The use of precast sections eliminates costly and time-consuming wooden formwork, creates a system of mass production that can begin even while the foundations are being dug, speeds construction, and is economical. At Turin the hall is covered by precast sections 1 1/2 inches thick forming undulating ribs that carry the structural load across the 328-foot-wide room to fan-shaped piers at the sides. It took just seven months to erect. One critic likened the hall to a suspension bridge, "for it has the sense of materials being pushed to their utmost, yet without ever appearing to strain," as Goldberger noted.
In 1946 Nervi began lecturing on architectural engineering at Rome University. He collaborated with other architects on a series of internationally important buildings in the 1950s. The UNESCO Building in Paris (with Marcel Breuer and others, 1952-1957) has a reinforced-concrete structure, the most interesting part of which is the continuous folded slab of the walls and roof of the General Assembly. The 32-story Pirelli Office Building in Milan (with Gio Ponti and others, 1955-1956) has a more traditional load-bearing structural system. Nervi also designed two sports arenas erected for the Roman Olympics of 1960. The 5,000-seat "little palace" (with Annibale Vitelozzi, 1957) has prefabricated diamond-shaped sections descending from an overhead compression ring to exposed, prefabricated, Y-shaped piers sloped to receive their diagonal thrusts. The 16,000-seat "palace" (with M. Piacentini, 1958-1960), has piers covered on the exterior by a glass skirt.
For the Palace of Labor in Turin (1960-1961) Nervi combined reinforced concrete with steel (designed by G. Covre) to create a large rectangular hall filled with a forest of treelike structures forming ceiling and support. At the Burgo Paper Mill outside Mantua (1961-1962) he used steel cables (also by Covre) suspended between concrete piers to create a clear span of 525 feet.
Nervi collaborated on projects as far afield as Australia and the United States. The Bus Station at the George Washington Bridge in New York City, famous for the butterfly-like wings of exposed concrete that make up its roof, and the Field House for Dartmouth College in New Hampshire (both 1961-1962) were erected at the same time that he was delivering the Charles Eliot Norton Lectures at Harvard University. In 1964 he received the Gold Medal of the American Institute of Architects, the highest honor in American architecture. Nervi's bus station design helped him win fame in the United States, but its design was altered later because open spaces between the concrete wings, left to allow bus fumes to escape, let cold winds off the Hudson River intrude.
The delicacy of the lacy coverings for large-span halls such as that at Chianciano (1952) and the Roman sports palaces might lead one to forget how essentially businesslike was Nervi's approach to structure. He looked and thought exactly like what he was: the head of a firm engaged in the cutthroat business of building. In his writings, Nervi constantly reminded readers that 90 percent of his contracts were awarded in competitions where the governing factors were economy and speed of construction. He thrived on these limitations and, indeed, "never found this relentless search for economy an obstacle to achieving the expressiveness of form" desired.
Architecture, for Nervi, was "a synthesis of technology and art." To find the logical solution to a limiting set of factors within a highly competitive situation was, for him, "to build correctly." His mastery of concrete bespoke a love for its adaptability. "Concrete is a living creature which can adapt itself to any form, any need, any stress," he once said.
Further Reading on Pier Luigi Nervi
Structures (1956); Buildings, Projects, Structures, 1953-1963 (trans. 1963), which contains many illustrations of his works, and Aesthetics and Technology in Building (1965) by Nervi are in English; Pier Luigi Nervi (1960), by Ada Louise Huxtable, is well illustrated; sketches on Nervi are also available in Muriel Emanuel, ed., Contemporary Architects (1994); and in Randall J. Van Vynckt, ed., International Dictionary of Architects and Architecture (1993).