Reinforced-Cement Structural Members
Reinforced-Cement Structural Members
thin-walled structural components made from fine-grained concrete, reinforced in parts by woven or welded grids made from fine wire.
Reinforced-cement structural members are utilized as bearing and protective structural members of buildings and installations and in the construction of reservoirs, shipbuilding, and so on. Such members were first used by P. L. Nervi in Italy for the construction of a seagoing yacht (1943), and later in combination with monolithic reinforced-concrete elements for long-span ceilings—for example, in erecting the vault of an exhibition hall with a span of 100 m in Turin or the dome of the Palace of Sport in Rome (1958–60).
In the USSR reinforced-cement structural members are used for the most part in precast ceilings made from enlarged elements (for example, arched market ceilings with a span of 15 m in Leningrad). Such ceilings, constructed from steel tie beams with reinforcement of the slabs with two woven grids, have a reduced concrete thickness of 4.1 cm and a specific expenditure of steel of 5.4 kg per sq m. Reinforced-cement structural members are manufactured using high-density concretes of type 300 and higher, with cement expenditure of 500–700 kg per cu m of concrete. In comparison with structural members made of ordinary reinforced concrete, reinforced-cement structural members are distinguished by the thinness of their walls (15–20 mm), an increased waterproofing quality, and a dispersed distribution and slower rate of appearance of cracks. The shortcomings of reinforced-cement structural members are a comparatively low resistance to fire and a necessity for anticorrosion protection of the surface of the concrete and the reinforcement under conditions of increased humidity. Reinforced-cement structural members are generally installed in the form of beams and vault elements of corrugated or wavelike profile or of shells with a single or double curve. Such forms are manufactured in steel, concrete, or wooden forms, with mechanized compaction of the concrete mix.
The further development of reinforced-cement structural members is connected with the use of high-strength concrete, standardized elements, and improvements in their manufacture at plants. Reinforced-cement structural members, which are light and inexpensive, allow the creation of artistically integral interiors without any extraneous decorations or division by supporting elements. Ceilings made of reinforced-cement structural members are plastically expressive, and their component structural elements form a rich decor.
REFERENCES
Nervi, P. L. Stroit’ praviino: Puti razvitiia zhelezobetonnykh konstruktsii. Moscow, 1956. (Translated from Italian.)Armotsementnye konstruktsii v stroitel’stve. Leningrad, 1963.
Ukazaniia po proektirovaniiu armotsementnykh konstruktsii SM-366–67. Moscow, 1967.
Rodov, G. S. Armotsementnye konstruktsii dlia promyshlennykh sel’skokhoziaistvennykh i grazhdanskikh zdanii. Moscow, 1968.
G. K. KHAIDUKOV