Asbestos Cement Industry
Asbestos Cement Industry
one of the most important branches of the building materials industry. The asbestos cement industry is concerned with the production of various kinds of roofing, wall, and facing sheet materials; pressure and nonpressure pipes; electrical insulation boards; building details; structural components; and other products made from a base of asbestos and cement. The cost of asbestos cement sheet roofing for housing and public buildings is approximately half as much as roofing made of roofing steel. Asbestos cement pressure pipes are considerably less expensive and lighter than cast-iron or steel pipes; on the average, 1 kg of asbestos cement replaces from 1.5 to 2.5 kg of metal.
Asbestos cement was first produced at the end of the 19th century; in prerevolutionary Russia it had just begun to be produced. The presence of extremely large deposits of asbestos (the USSR is first in the world in these deposits), as well as the vigorous growth of the cement industry, ensured high growth rates for asbestos cement production in the USSR (see Table 1).
The production of asbestos cement products in the USSR grew considerably faster than the output of other interchangeable building materials. Thus, if the production of soft roofing material from 1940 to 1968 increased 9.2 times and
|Table 1. Production of asbestos cement products in the USSR|
|Years||Sheet materials and products (slate) (in millions of conventional tiles)1||Pipes (conventional) (km)2||Electric insulating board (tons)|
|1 Calculated for sheets 40 x 40 cm in size|
|2 Calculated for pipes 200 mm in diameter|
roof tiles 1.6 times, the output of slate during this period increased 25 times over. The proportion of slate in the all-Union production of basic roofing materials, calculated in terms of area of roof covering, rose from 20 percent in 1940 to 53–55 percent in 1965–66. The production of asbestos cement pipe in 1968 was 34.4 times that of 1940. This increase was accounted for by the construction of new plants and by the expansion and engineering redesign of previously existing enterprises, as well as by the intensive development of technical processes. In terms of the total level of production of asbestos cement products and their per capita output, the USSR ranks first in the world, with more than half of the total world output of these products.
In the total expenditure of raw materials used in manufacturing asbestos cement products, about 85 percent is cement and only 15 percent is asbestos; therefore, asbestos cement enterprises are, as a rule, built close to cement plants. Asbestos cement products are manufactured in all the Union republics. In the all-Union production of slate the relative importance of the eastern regions of the USSR (including the Urals), where an especially large amount of building is being carried on, rose from 12 percent in 1940 to 38 percent in 1968. The specifics of the technology and the type of raw material being utilized determine the high material resource consumption of this production (raw and auxiliary materials account for more than 71 percent of all expenditures), as well as its low requirements in fuel and power (fuel and electric power constitute about 5.5 percent of the expenditures). As a result of the comparatively lengthy cycle taken up by hardening the semimanufactured material, which requires large production areas, the proportion of cost required for buildings in basic production in the asbestos cement industry is quite high (approximately 57 percent).
The structure of the standardized working capital funds of the asbestos cement industry is as follows: production reserves, 60.3 percent; unfinished production and semimanufactured products, 17.4 percent; expenses for future periods, 0.3 percent; finished output in stock, 18.6 percent; and the remainder, 3.4.
The technical reequipment of asbestos cement enterprises carried out during the postwar period and the intensification of engineering processes, as well as the dissemination of the experience of production innovators, guaranteed the increased productivity of equipment and the growth of labor productivity. Thus, the average annual output of slate from one sheet-forming machine 1.6 m in width rose from 12.6 million standard slabs in 1950 to 28.5 million in 1968. The average annual output of slate from one worker, measured in thousands of standard slabs, increased from 153 in 1955 to 239 in 1967.
During the five-year plan of 1966–70 the asbestos cement industry achieved further growth. The output of asbestos cement sheet materials and products in 1970 was predicted to reach 5.8 billion standard slabs, or 1.4 times more than in 1965. Asbestos cement pipe was scheduled to reach 51,000 conventional km, or 1.6 times more than in 1965.
The basic trends of technical progress in the asbestos cement industry are as follows: broadening the variety of asbestos cement products in order to increase their economic effectiveness in construction and in the industrialization of building operations; improving quality and reliability in order to increase the durability of structural components and installations; producing considerably more large-scale asbestos cement sheets of economic designs, large-scale structural components for the roofs of industrial buildings and wall partitions in the form of heat-insulating slabs and panels, effective integrated fiberboard sheets for mass construction, and asbestos cement pipe for gas lines, heating systems, and the like; comprehensive mechanizing of production and introducing automated systems into the preparatory and fabrication sections of asbestos cement plants; introducing efficient, more powerful equipment, new types of sheet-forming and pipe-forming machines, and other improvements; and perfecting technology and intensifying the processes of forming and hardening slate and pipes.
The asbestos cement industry has attained considerable growth in a number of socialist countries, especially in Poland, the German Democratic Republic, Czechoslovakia, Bulgaria, Hungary, and Yugoslavia. Among the capitalist countries the production of asbestos cement products has been most highly developed in the USA, Great Britain, the Federal Republic of Germany, Italy, France, and Japan (see Table 2).
|Table 2. Annual production of asbestos cement products in the most advanced capitalist countries (estimate for the period 1965–67)|
|Countries||Sheet products (in millions of conventional tiles)||Pipes (conventional km)|
|Great Britain ..........||300–360||10,000|
|West Germany ..........||730–760||4,400–6,500|
REFERENCESSokolov, P. N. Tekhnologiia asbestotsementnykh izdelii. Moscow, 1960.
Proizvodstvo asbestotsementnykh izdelii, 2nd ed. Moscow, 1962.
Satarin, V. I., and V. A. Akopian. Asbestotsementnaia promyshlennost’. Moscow, 1962.
Fel’zenbaum, V. G. Asbestotsementnaia promyshlennost’ zarubezhom. Moscow, 1960.
Promyshlennost’ stroitel’nykh materialov SSSR, 1917–1967. Moscow, 1967.
V. E. SHNEIDER