Review of major trends in the introduction of new building materials in the USSR and socialist countries of Eastern Europe

V. I. O \ ' S Y A N K I N

Vicrl- Presiclent of the U S S R Accr t /~r r~ j . of Bililcling ui~d Architectrirc ( U S S R )

I N T R O D U C T I O N

The 20th century, especially its second half, has been marked by the advent of a large number of new building materials and products. This has been acconipanied by the emer- gence of new methods for the production and use of traditional materials.

The basic incentive for the development of the production of new materials and new niethods of utilizing conventional materials springs from the vast construction programme in the USSR and East European couritries which originated froni the reconstruction work after the Second World War and, above all, from the necessity for a rapid rise in the living standards of the people. Owing to the existence of a planned econoniy in the USSR and socialist countries of Eastern Europe, the programme is being implemented in accordance with plans to develop the national economy of these countries, stipulating a large volume of housirig, public and industrial construction.

The drive to save inan-hours, construction time and costs as well as to improve quality, ensuing from the large amounts of coiistruction req~iired, have resulted in the emergence of industrial methods of construction, weight reduction of buildings and increase of the size of precast units. This has, in turn, involved the eniergence of new and efficient structural, heat- and sound-insulating, waterproof and finisliing materials and products.

The main factors wliicli ensure tlie development of the building industry and the advent of new niaterials arid products are as follows:

(a) Latest achievements in physics, chemistry and other basic sciences; (b) Considerable expansion of basic raw materials; (C) Replacement of handicraft methods by niechanized and au toniated industrial produc-

tion. As a result, new branches of industry have been created to process raw inaterials into

finished products and building units. The new architect~iral and town-planning tasks and the resulting progressive structural designs based on assemblage, large sizes and weight reduction, strongly influence the Progress in investigations, development and production of new building materials and products.

The use of new building materials has substantially affected not only the structural design, methods, economy and quality of construction, but also the architecture of buildings and large housing blocks. This question was dealt with at the VIth LllA Congress at London in July, 1960.

G R O W T H O F P R O D U C T I O I V O F N E W B U I L D I N G M A T E R I A L S

A N D P R O D U C T S

C E M E N T

In view of the sharp increase in the output of reinforced concrete units and structures in the USSR and East European countries, the cement industry is developing at a partic-

ularly rapid rate. Various new kinds of cement are now available. l'he output of cement in 1960 as coil~pared with 1950 is shown in Table I .

T A B L E 1

CEMENT OUTPUT

(millions of toiis)

Bcilgaria Hungary German Democratic Repciblic Poland Rumania USSR Czechoslova kia

Total

Fig I . Large-panel dwelling construction in the Fili-Mazilov area, Moscow, USSR. Panel tinish by ceraniic lii-iing in two colocirs (white and dark red).

Fig. 2. Large-panel dwelling construction at the Antala Stnscheka settlenient, Pankrau, Praglie. Czechoslo\nkia.

Fig. 3. Large-panel dwelling constructicin at God\valdo\, C~echoslo\akia.

Fig. 4. Large-panel dwelling constrLiction in the 'Al. Tolstoi' coniplex, Sotia, Biilgaria.

The increase in the production of cenient is acconipanied by iniprovement of the quality and widening of the raiige of cements.

In the USSR the average strength of ceinent increased froin 353 kg/cinVn 1950 to 429 kg/cm2 in 1960, the average strength of Portland cenient amounting to 482 kg/cin2 in 1960. In 1950, higli-strength cements, Iiaving tlie strength of 500 kg/cm2 and higher accounted for 17 per Cent of the total output of cenient, while in 1960 this percentage increased to 37. Ceinent with a strength of 700 kg/cm"s being produced and production of an 800 kg/cni2 cement is about to be started.

The quality of cement is steadily iinproving i n all East Europerin countries. In 1925 Portland cement was alniost the only type of cenient produced in the USSR.

In tlie following years, and especially during tlie last decade, production was started of new kinds of cenient: pozzolanic and slag Portland ceinent, oil and gas well-cement, plasticized and water-repellent, quick-hardening, sulpliate-resistant, magnesia Portland cerrient and low-heat (belite) ceiiient. Al~iniinous, expanding, white and coloured, acid-resistant and other kinds of cements are also produced. The production of quick-hardening slag Portland cenient has been started.

In the Soviet Union and socialist countries of Eastern Europe the total output of cenient in 1965, as coiiipared with 1960, is expected to increase by soi-rie 82 or 83 per cent. In 1965 the production of ceinent in the USSR will exceed 80 niillion tons.

P R E C A S T R E I N F O R C E O C O N C R E T E . L I G H T W F 1 C ; H T C O N C K E T E S A N D LICiHTWCICiHT

A G G R E G A T E S

As a result of tlie widespread introduction of iiidustrial methods of construction, the output of precast reinforced concrete and its use in construction increased sharply in the Soviet Union over the last ten years. In fact, a new industry of precast reinforced concrete has emerged in the USSR in recent years, coiiiprising a great number of specialized plants and large house-building factories all over the country.

Since 1950 the output of precast reinforced concrete has increased 24 times and amounted to 32 million m3 in 1960.

The range of precast reinforced concrete products has been considerably widened, the sizes increased and production of prestressed concrete structures has been started.

A furtlier annual increase in the volume of production of precast reinforced concrete has been plaiined on a larger scale to reach at least 55 million in%y 1965, including 14 million m3 of prestressed concrete, 9.5 million m3 of wall panels and 3.5 million n13 of precast reinforced silicate concrete structures and units.

The following trends, common to each kind of construction, can be noted in the develop- ment and improvement of precast reinforced concrete structures:

(a) Reduction of the weiglit of structures by adopting thin-walled elements made of high-strengt11 ordinary and prestressed concrete, as well as by using low-density concrete;

(b) Increase of the dimensions of factory-made units and their degree of finishing in order to obtain a greater degree of prefabrication of buildings and structures.

The factory production of building units and products has resulted in a substantial increase in the output of liglitweight concretes made with porous aggregates (cellular concretes) as weil as autoclaved silicate concretes made with lime, siliceous aiid slag binders.

The iinproved technology of foam and gas concrete made it possible to produce cellular concretes of high strength and relatively low density.

Wide application is being made of 'no-cement' and, above all, silicate concretes, both cellular and dense, as well as reinforced structures made of these autoclaved silicate con- cretes.

Expanded clay plastic concrete, a new type of no-cement concrete, has been produced. This is a light material of low heat conductivity with a synthetic resin as a binder. Studies are under way to produce polymer concretes and reinforced plastic concretes possessing sonie improved properties as conipared with ordinary concrete and reinforced concrete.

Rapid growth in the production of precast reinforced concrete is likewise characteristic for all countries of Easterii Europe where the output of structures and units for housing and civil construction is substantially increasing. Great Progress in this field has been made by the Gernlan Democratic Republic, Poland and Czechoslovakia.

The production of precast reinforced concrete in the socialist countries of Eastern Europe (excluding the USSR) amounted to approximately 4 niillion m3 in 1958 and is expected to rise to 13 or 14 million m3 by 1965.

In Bulgaria expanded clay concrete and expanded clay perlite concrete will be used niainly for large-panel construction. Cellular concretes comprise autoclaved foamed con- cretes, the trend being to expand tlie output of foam silicate concrete. Their production will be considerably increased during the next few years.

In Hungary prestressed concrete floor elenients have foiind the widest application. Their output amounts to 520,000 m" or 70 per cent of the annual volunie of floor elements for State hoilsing construction.

In Czechoslovakia niass production of cellular concretes and lightweight concretes made with blast furnace slag and power plant fly-ashes has been started. In the near future plants are to be built with an annual capacity of 1.8 million m3 of cellular concrete, including 1.6 million m3 made with the fly-ashes of heat and power plants.

Considerable achievements in the production of gas concretes have been made in Poland. In view of the increased production of lightweight concretes for various purposes, consid-

erable attention is being paid in the USSR and in all socialist countries of Eastern Europe to arranging and developing the production of artificial lightweight aggregates in relation with the use of porous rock and industrial waste products (fuel slag, porous metallurgical waste slag, power plant fly-ashes, etc.). Local raw material resources niay contribute to a large-scale production of the following basic types of artificial porous aggregates: expanded clay, agglomerated expanded clay, slag p~iniice and expanded perlite.

The total output of artificial lightweight aggregates in the USSR and in East European countries has been planned to reach the following amounts by 1965 (thousands of m"):

Expanded clay 8,260 Agglomerated expanded clay 4,945 Slag pumice 8,035

Total 21.240

H E A T - A N D SOUND-INSULATING M A T E R I A L S

lncreased construction based on large-sized prefabricated iinits calls for ever greater quantities of heat-insulating materials.

Mineral wool and felt and their associated products, based on bitumen and, to a lesser extent, on synthetic binders, account for niost of the heat-insulating materials used in the USSR. It is envisaged to develop the production of mineral wo01 based exclusively on synthetic binders.

Production of heat-insulating materials niade of tibre glass, foain glass, expanded perlite and vermiculite, foani plastics, insulating tibreboards, fibrolite, reed mats, etc. has also been started.

As compared with 1958, the output of niineral wo01 and its products is expected to increase approximately fourfold by 1965, that of fibre glass products 30 times, ljbrolite 66 times, foani plastics 14 times and vermiculite products 3 times. The production of reed niats, insulating fibreboards, perlite and foam-glass products will also be increased considerably.

A rapid growtli of the production of all kinds of heat- and sound-insulating inaterials is likewise observed in other countries of Eastern Europe. The production of niineral wool and its products, glass wool, fibre glass and associated products, as well as insulating fibre- boards, is being expanded.

Bulgaria produces cellular concrete (foani concrete) heat-insulating blocks, slabs and Segments for insulating pipelines as well as Iieat-insulating fibre glass and basalt wool mats. wood-wo01 cement and reed niats. Production of expanded perlite is about to be started.

Hungary produces expanded perlite, foained polystyrene and flax fibre boards. Poland produces, along with other materials. insulating fibreboards and basalt wool.

M E T A 1.S

During the last decade the iron and steel industry began producing new kinds of rolled steel for construction. Whereas iip to 1955 'CT. 3' (niild steel with the strengt11 of 23 kg/inni2) was used as the basic material for nietal structures, in recent years new types of steel of higher strength (33-35 kg/inni" have been introduced.

The USSR and East European countries produce on a large scale new kinds of high- tensile cold-drawn deformed steel (with an ultimate strength of 140-200 kg/mni2), as well as the wire and strand steel for reinforcing concrete structures.

In 1960 the USSR used about two million tons of steel for metal structures and some four ii-iillion tons of reinforcing steel.

The production of new kinds of products made of aluminium alloys is very important for modern construction. These include facing sheets for light curtain-wall panels, profiled details for windows, shop windows and doors, folding decks and roofiiig panels (for industrial buildings), details of acoustic perforated suspended ceilings and light demount- able building structures to be erected in remote and almost inaccessible areas.

Sheet structures and shapes of thin bent sheets have likewise found a wide application. A special range of pressed products niade of aluininium alloys Iias been developed and iiitroduced into practice. A wide range of pressed pipes is available.

In the future aluniiniuni alloys might also be used in the loadbearing roof structures of large-span public and iridustrial buildings and in industrial structures subject to corrosion

service conditions, as well as for pipelines, portable structures, sectional falsework and scaffolding.

ßy 1965 the USSR is to increase the output of aluminium 2.8-3 times as coinpared with 1958.

R O L L R O O F I N G A N D W A T E R P R O O F M A T E R I A L S

Roll roofing materials account for an ever-increasing share in the total output of roofing materials both in the USSR and in a number of East European countries as a result of a gradual iransition to tlie construction of buildings with flat roofs. In the USSR tlie produc- tion of soft roofing materials increased from 285.5 niillion m v n 1950 to 750 million ni2 in 1960. Today these materials account for about 40 per Cent of the total output of roofing materials.

In Poland the output of soft roofing materials increased from 39.2 niillion m q n 1949 t o 88.3 niillion m2 in 1958. Resin-impregnated tar paper and bituminous felt are being iiianufactured and production has been envisaged of tar paper based on fibre glass.

Rumania likewise produces roll roofing and waterproof materials on a large scale. In tlie other couiitries this branch of industry has been growing at a slower pace.

Tlie LJSSR and other East European countries also produce such riew n~aterials as bituminous felt aiid tar paper with coarse-grained surfacings. Tlie USSR also produces hydroisol with the asbestos paper backing. Asbestos-bitunien borulin 2 , isol and brysol 3

are waterproof rubber-backed materials. A metliod has been developed to spray water- proof mastics and fibre glass on roofings. This niethod provides a reliable surface, thus eliniinating the need to erect factories producing roll materials.

Czechoslovakia and Hungary have begun the production of roll roofing materials with glass fabric backing. In the next few years the USSR will likewise produce this material. Apart from this, 'Hydrokam', a new high-grade waterproof material obtained by mixing petroleum bitumens and tar products, is soon to be produced.

Bulgaria produces a bituminous henip cloth and tar paper. Production is envisaged of reinforced bituminous felt based on plastics and glass fabi-ic.

In view of the extensive use of flat roofs without garrets in housing construction. the outp~i t of soft roofing materials in the USSR is to be doubled by 1965 as compared with 1960.

ASBESTOS-CEMENT P R O D U C T S

The important technical and economic advantages of asbestos cenient as a building material and the availability of great asbestos resources in the USSR have made inevitable the rapidly increasiiig rate of output of asbestos-cement products in the USSR and in a nuniber of East European countries.

In 1960 the output of roofing asbestos-cement sheet niaterials in the USSR aniounted to sonie 300 million n i h s against 55 million ni' of boards in 1950 and 150 niillion m v n 1955. Besides the USSR the asbestos-ceinent industry is niost developed in Czechoslovakia where its products account for inost of tlie roofing iiiaterials produced by the industry. Asbestos-ceinent boards have likewise found a wide application in Poland.

By 1965 the total output of roofing slates in the USSR and socialist countries of Eastern Europe is expected to rise approxiniately 2.5 times above the 1958 level.

Production of asbestos-cement pipes is growing apace. In 1960 the output of such pipes in the USSR was 18,653 kilometres as against 3.500 in 1950 and 12,148 in 1955. A new industry of asbestos-cement pipes is being created in the Gerinan Deniocratic Republic and Poland. It is hoped to increase the total outpiit of sucli pipes in the USSR and East

Hydroisol: bituminous asbestos board. "oriilin: roll waterproof material of calendered bitumiiious mastic :3 Brysol : roll bitiimen-rubberized waterproof material.

Europeaii count riei froin 18,300 kiloiiietrei in 1958 to 55,000 in 1965, i.e. approxiinately three tiiiies as iniich.

In postwar years the range of asbestos-ceinent products in tlie USSR has been consider- ably expaiided. Tlie inanufxture h~ i s been started of new kinds of products, siich as large- sired corrugated asbestos-cetiient slieets and prefiibricated insulated boards for roofs of indiistrial buildings, faciiig sheets coated with polyvinylchloride enaniels for iinisliing I\itcliens, bathrooins and toilets, special 'iiiiibrellas' for waterproofing and finishing lobbies of ~iiiderground stations and veiitilatiiig ducts. The same material is used for prefabricated toilet cabins made of Fdcing aibestos-ceinent slieets, and for large-sized asbestos-cement priiiels for walls and roofs.

Betcveen 1956 and 1960 tlie output of window glass in the USSR increased by 48.5 per cent and aiiiounted to 147.2 iiiillion i n 5 n 1960. The iise of high-capacity conveyors for grinding and polisliiiig glass resulted in a 2.6 times increase in the production of polished glass. In tlie saiiie period the output of glass blocks increased 19.8 times. Tliere has been considerable expansion of tlie prodiiction of reinforced glass.

I i i recent years tlie USSR has begun to produce a nuinber of new types of product, such as large-sized polished iind unpolislied sliop-window glass, figured glass, hardened glass and allied prodiicts, glass units for glazing window openings, glass facing tiles, carpet glass iiiosaic and Iieat-resistant glass pipes.

Prod uctioii is envisaged o f t h ree-layer wall panels faced wi t h large-sized sheet glass coated on one side with ceraniic opaque glazes.

A su bstantial increase has been recorded in tlie production of architectural and structural glass in Czeclioslovakia, Poland. Bulgaria and Hungary. Czeclioslovakia mass produces sl~op-window, liardened. reinforced. figured and facing glass and hollow glass blocks.

During tlie lait decade tlie runge of wall ceramic niaterials has undergone a considerable cliange along witli a substantial increase in output in the USSR. A sharp increase has been i-ecorded i i i tlie production and use of high-grade hollow bricks and Iiollow ceramic blocks.

A great variety of ceramic panels and tiles is being produced for outer and inner facing of buildings and mass production of tliin ceramic finishing layers has been introduced for factory-facing large-sized reinforced concrete wall pünels.

Tlie pi-oduction of sanitary ceraiiiic Mtare, floor tiles (siiiooth, in 'carpet' form and figured, textured), glazed facing tiles (white and coloured) and sewage pipes has rapidly developed in the USSR. For exaiiiple. in 1960 the output of sanitary Ware increased I0 times, floor tiles I 1 times, Fdcing glüzed tiles 28 tiines iind sewage pipes 10 times as compared with 1950.

The saiiie is truc ofotlier East European couiitries. For instaiice, the production of hollow brick\ in Bulgaria increased froin 1 per Cent in I958 to 25 per cent of the total volume of oi-dinai-y brick. Bulgar-ia also produces cerainic floor panels and lias developed a niass production of facing faience and terra cotta tiles.

In Czechoilovakia the percentage of perforated and hollow bricks and blocks is to iiicrease fi-oni 33 to 49 in tlie next few years.

Glazed facing iiles are likewisc produced on an increased scale in East European coun- ti-ies. Apart from the USSR, floor tile industries o f high capacity have been created in the Geriiiaii Dzinocratic Republic aiid in Czeclioslovakia.

I'OI*YMLR UUILUINC; R.IA71 R I A L S A N U I 'RODIJCTS

Tlie light weiglit, streiigtli, reasoiiably large diniensions, characteristic physical and inec1i;inical properties, architectiiral and building qiialities of polynier iiiaterials and prod- iicts meet the i-eqiiirements OE n~ode rn industrial met hods of construction. Their inass

production is facilitated by the availability of unlimited raw materials necessary for obtaiil- ing the basic products and by tl-ie ease of their processing (by pressing, moulding, calender- ing, etc.). The other favourable factors are the relatively small capital investments for organizing such production and the possibility of complete niechanization and automation of the technological processes.

The polymer building tnaterials and products industry has been created during the last few years in the USSR and East European countries. The USSR has organized large-scale production of roll and tile flooring materials, laminated plastics from resin-bonded paper, laminated wood plastics, chipboards, organic glass, glass-reinforced plastics, linoleuni wall covering, washable wall paper and films, fibreboards impregnated with synthetic resins, facing products, varnishes, lacquers and paints based on synthetic resins, soft and rigid porous plastics, glues, mastics and emulsions, pipes and equipment for sanitary services, window and door fittings, and electrical equipment.

Many of these materials and products are also fabricated in East European countries. Production of polymer materials is most developed in the German Democratic Repiiblic, Czechoslovakia and Poland.

A general impression of the scope and rate of growth of the polynier building-material industry in the USSR may be gained from Table 11.

T A B L E l l P R O D U C T I O N O F POLYMER MATERIALS I N T H E USSR

Urlit of Produced N I nleasurenler~t 1950

Roll flooriiigs millioiis of m2 13.3 Floor aiid wall tiles 0.74 Linoleum wall covering ,, 2.5 Laminated resin-bonded paper plastics ,, 1 .08 Laniinated wood plastics tliousands of tons 6.55 Chipboards thousaiids of m:' 156

P

Planned for 1965

.

I N F L U E N C E O F N E W B U I L D I N G M A T E R I A L S O N D E S I G N

A N D C O N S T R U C T I O N

N E W W A Y S O F U S I N G C O N V E N T I O N A L B U I L D l N G M A T E R I A L S A N D P R O D U C T S

Simultaneously with the increased production and application of new building niaterials, traditional building materials sucli as natiiral stone, brick, concrete, steel and glass have acquired new properties and found new fields of application. 'l'heir production is being niodernizsd and perfected.

The mechariized fabrication of facing slabs of natiiral stone has permitted a reduction of thickness to 20-25 mm for large-sized slabs and down to 12 mn7 for small-sized ones. This has created econoniic conditions favouring their wider use together with new niaterials.

Blocks sawn out of rock by a mechanized process are extensively used in the southern regions of the USSR for facing wall niasonry, thus eliminating any additional finishing.

New types of perforated and t-iollow bricks and ceramic blocks have a lower coefficient of thermal conductivity, which allows the erection of thiniier walls, thus reducing the con- sumption of materials and the weight of the buildings. The new kinds of facing bricks and ceramic bloclts exteiisively used in East European countries are structural products with a finished surface. The colour and texture of the surface of such products inay be varied. They are successfully used together with new materials both for facades and interiors of buildings designed for various purposes.

Modern rolled-steel products have acquired new properties. Bent and cold-drawn thin-

walled shapes have appeared. Their use lias niade possible tlie design of more economical meta1 structures.

Concrete is being substaiitially niodernized as a result of changing its niix design and einployiiig a new technology of nianufacturirig. High-strength, lightweight, cellular. no- cenient (silicate), polymer and gypsum concretes have appeared.

Tlie eniergence of precast reiiiforced concrete, along with the new kinds of concrete, has become a decisive factor in the developmetit of industi-ial coristruction in the USSR and East European countries.

Improved production of glass resulted in its wider range of application in construction. This is boriie out by the experience of modern constructiori in the USSR and East Europeari

Fig. 5. Hotel J unostj, Moscow, USS R. Horizontally arranged wall panels with finish of white-grey crushed inarble. Piers between windows finished with blue corrugated asbestos-cernent sheets.

countries. Large areas of glass provide better lighting and help to create iiiodern architec- tural designs. Hardened glass is f~irther strengthened.

Conventional rnaterials in their traditional foriii Iiave likewise found new applicatioiis. For instance, ordinary clay brick is used in the USSR and sonie East European countries to make large wall blocks for liousing construction. Construction with the large brick blocks is particiilarly prevalent in Czechoslovakia.

Ordinary clay brick is partly used in the USSK to niake vibro-brick panels. Sinall-sized facing cerainics and granulated stone chips are iised for factory finishing the outer face of large-sized wall panels. Asbestos-cement sheets are also used for prefabricated wall panels.

New building materials and products are being increasingly used together and in coin- bination with both the traditional and modernized conventional materials.

New polymer finishing and structural ii~aterials and products are used in coinbination with stone, brick, concrete, reinforced concrete, wood. nietals and glass and with their modern variations.

The experience of modern construction iri the USSK and East European countries has

Fig. 6. Kremlin Congress Palace, Moscow, USSR. Detail of faqade: niain entrance. Piers finished in marble slabs with vertically corrugated surface. Space between piers glazed up to storey height by large-size polished glass windows with anodized aluminium sashes. At ceiling level three-layer prntecting panels, lined with black glais, coloured at the back during production. Awning over entrance of prefabricated aluminiuni sections with anodized aluminiiim profiles. Glazing of entrance of large-size polished glass elements. Doors

of hardened glass.

Fig. 7. Exhibition hall at Sokoljniki. Moscow, USSR. Principal niaterials: aluniiniiim and large-size glass elcments.

shown that a proper combination of nek rriaterials and modernized conventional niaterials eiisures not only considerable technical and ecorioniic advantages but also new artistic and coiilpoiitional possibilities.

Fig. 8. 'Russia' Cineniü, Moscow. USSR. Interior view ofhall with 2500 seats. Walls covered with vertical polyvinyl-chloride profiled elenients, and partly with wood-chip slabs. Suspendcd ceiling of wood-chip slabs.

Seats covered with textovynite.

Fig. 9, 'Tsjcrnoniorets' Sanntori~ini, Livudia, Criniea, USSR. Clcib ciitrancc hall. Floor of polyvinyl- chloride slabs. \Y;ills lined with proliled tinibcr 1 ~ 1 t h ~ . Wiiidows of I~irge-sire giass sections.

I N F L U E N C E O F N E W H I J I L D I N G M A T E R I A L S O N D E S I G N A N D C O N S T R U C T I O N

M E T H O D S

'Phe organization of a new efficient building material and product industry and the in~proveriient and ii~odernization of the production of conventional materials greatly in- fluence the increase of productivity in the building industry, in design and in methods of construction.

Mechanized prefabrication of reinforced concrete products involves a replacement of Cast in situ structures by precast ones and an extensive ~inification of structural units for buildings and structures on the basis of a modular system.

Increased output of high-stre~igth cements has contributed to the production of high- strength concretes. The use of high-tensile reinforcing steels resulted in a transition from smooth to deformed prestressed or non-prestressed reinforcenient.

All tliis, together with the production of high-strength and crack-resistant concretes, has substantially altered the methods of designing, while tlie improved ratio of height to Span Iias inade it possible to increase considerably the liniit dimensions of Spans, bringing about new design and architectural forms.

The development of lightweight and cellular concretes has made possible the extensive in- troduction of large-panel housing construction and tlie use of large-sized wall and roof ~inits wliich conibine supportingand enclosing functions in publicand industrial buildings. This lias also beeri helped by the emergence of a nurnber of new heat- and sound-insulating materials.

The developrnent of heat-resistant concretes has not only enabled replacenient of the firebrick lining in inany industrial units and furnaces but also the creation in niany cases of new lieat-resistant reinforced concrete structures.

Tlie production of large concrete blocks, clay brick blocks and panels has substantially changed the methods of erecting masonry buildings and greatly influenced their design.

In Soviet housing constriiction, precast reinforced concrete has completely replaced wood and ilz situ coticrete in floors and staircases, and is successfully replacitig rubble aiid rubble- concrete foundations.

Owing to the developnient of new types of unified prefabricated units and structures, various series of blocks of flats niade of large-sized units have been designed in the USSR and East European countries for mass construction. This marlts the beginning of an inipor- tant new industry of prefabricated housing consti-uction, which is represented best by the house-building factories Set ~ i p in Moscow, Leiiingrad and other towns.

In 1960 Soviet housing construction, with the lise of large-sized units, amounted to three million r n k f floor space, and this is expected to exceed 25 million m2 in 1965. Each passing year niarks a siniilar increase in large-panel housing construction in Czechoslovakia, Poland, the Geriilaii Deniocratic Repiiblic, Rumania and Bulgaria.

In vol~irrie of precast reinforced concrete and large-panel construction, the USSR holds the first place in the world.

It has been possible to increase considerably tlie diniensions of precast units and to raise the degree of their prefabrication. Between 1947 and 1950 tlie average area of the panels did not exceed 4-4.5 13% now wide use is being made of floor and inner-wall panels having an area of 16-18 111~1id outer wall panels of 12-1 3 ni2.

I'he iritroduction of new building materials and niethods for the fabrication of precast units has contributed to new architect~iral planning and structural designs of large-panel buildings. For exainple, the application of a new technology developed in the USSR for the fabrication of panels and the increase in the spacing between the transverse rows of supports liave periiiitted the adoption of a 'free' planning of flats with a flexible arrangement of inner partitions depending on the size of the faniily and the way of life. This method of planning flats has also becoiiie very popular in Czechoslovakia.

In tlie practice of construction in the USSR and East European countries rnany interest-

ing designs of large-pariel blocks of flats have been found wliose finish and texture are attributable imainly to the materials used and the technology of casting wall panels.

Iiiiproved moulding niethods luve made it possible to obtain faqade surfaces of panels with a finished texture and all the inner surfaces ready for finishing, thus substaritially saving the labour and time required for finishing operations.

'I'he utilization of such materials as asbestos cement, plastics rind al~iniini~ini for outer walls, in addition to reinforced concrete, facilitates the erection of frame buildings with light curtain-wall panels, which are new in their architecture rind design.

The organization of the large-scale production of polynier materials affords wide op- portunities for tl-ieir use in the construction of residential, p~iblic and industrial buildings

Fig. 10. Covered market of Newski quarler, Leiiingrad. USSR. Arched roof with 15-rn span.

as well as in the manufacture of furniture. At the Same time such materials contribute to the creation of higher service standards and new aesthetic qualities of buildings.

liicreased production of new building materials a ~ i d the reduced weight of structures have favoured the appearance of new systenis of fully prefi~bricated construction. The erection of buildings by asseimbling entire prefabricated rooiiis (three-dimensional units) is a step Forward in large-sized precast construction which is being widely tested at present and which will make it possible to transfer to factories the bulk of work connected with the finishing operations and the installation of engineering equipinent in buildings.

The elaboration of standards for unified prefabricated units for mass construction of residential and public buildings allows the execution of a complex series of standard designs of residential and public buildings. Such a series is being elaborated now by the USSR Academy of Building and Architecture jointly with a number of design organizations. It includes blocks of flats of various types, hotel-type buildings, kindergartens and nurseries, schools and shopping centres.

In large-scale standard-design construction special importance is being attached to architectural and aesthetic qualities of construction, wl-iich so far lag behind the general level of industrialized construction. In this case, too, the wide range of building and finish- i ~ i g materials skilfully used by the architect can provide tlie required diversity of expression in the arcl-iitecture of biiildings and housing blocks.

Erich passing year also witiiesses an increase in the use of precast reinforced concrete for industrial buildings and structures in the USSR arid East European countries. In many cases the buildings are fully prefabricated.

A series of strindard supporting and enclosing units for industrial structures has beeil claborated on the basis of the extensive unificatiori of the basic building parameters and of external forces.

Fig. 1 I . Avtovo house-building factory, Leningrad, USSR. Trorough-shaped roof with 100-m Span.

Fig. 12. Mounting of production hall of a chemical group in the USSR, consisting of prefabricated reinforced concrete elenients.

Fig. 13. Factory bay of a rion-ferro~is iiietallurgy groiip at Bcidapest, Hcingary, with crane eqiiipnient. Monolithic vaultc and ctecl franie.

Fig. 14. Coristi~cictioii oF woi.ksliop in a cable factory at Hiidape\t, Hiiiigarq Prefabricated piess aiid vaiiltc.

Precast reinforced concrete used in industrial construction has proved its value for build- ings and structures designed for various purposes. The next step is to utilize other new effective lightweight and high-strength materials for industrial buildings (especially with large spans) - primarily alumini~im, plastics, high-tensile steel and extra-light insulating materials.

New niaterials and products with properties of light weight, high strength and large size contribute to the development of industrial methods of construction. These qualities iniply reduced labour and construction costs, shorter tiine for erection of buildings and the possible use of mechanized assenibling. The index of the degree of prefabrication (the proportion of prefabricated units in the total costs of niaterials and products) has reached 75 per Cent for large-block buildings and 85 per Cent for large-panel ones.

E F F E C T O F N E W I 3 U I L D I N G M A T E R I A L S O N E C O N O M Y A N D Q U A L I T Y O F

C O N S T R l J C T I O N

By now large-panel and large-block construction have been fully niastered and the tech- nical and economic characteristics niay be considered as sufficiently proved.

By way of illustration, tlie table below gives the basic data per square metre of useful area of large-panel, large-block and brick residential buildings, which provide a clue to the efficiency of the industrialized construction of buildings as well as showing the materials and products used in their erection. The figures are presented for the most widespread type: a five-storey, four-sectional apartnient building of 80 flats.

Type o f' bui l~ l ing

Estiniuted tost of Labour consrlnled Muterials Weipht

construc- (nian-~la-vs) ltsecl ( k g ) - -- -- - --

o f building

tioll At rite At juctory Total Stecl Ceir,eiit ( kg ) ( Roubles)

Large-panel rcinforced concrete building with cross loadbearing walls made of flat 'casette' panels and three-layer outer 67.1 1.9 1.1 3 14.2 120 1,030 panels with heat insulation of semi-rigid mineral wool slabs

-

Large-panel reinforced concrete building with outer two-layer walls with insula- 66.5 1.8 1.9 3.7 15.4 122 930 tion of non-autoclaved foam concrete and an inner reinforced framework

--- PP P P- --

Large-panel expanded clay coiicrete build- ing with outer loadbearing walls and re- 67.5 2 0.7 2.7 15.9 144 975 inforced concrete panels for inner cross walls and floors

Large-block building with three longitu- dinal Iightweight concrete walls (of 77 2.8 0.8 3.6 25.9 147 1,620 double-coursed vertical jointing) and reinforced concrete ribbed floors P- -- P- P

Brick bu~lding with three longitudinal loadbearing walls (outer walls of two 77.7 3.2 0.6 3.8 23.1 106 2,100 lightweight brick width)

The technical and economic effects resulting from the production and use of new building materials and prefabricated structures are as follows:

(a) In the building materials industry : developinent of the basic raw materials ; reduced capital invest ments per production unit ; labour savings ; reduction of production costs.

(b) In the construction of residential, public aiid industrial buildings and engineei-ing structiires:

reduced weight of structural uilits and of the building o r structure as a whole and, consequently, lower costs of transporting building inäterials and products; labour savings; reduction of construction costs and time saving; improved services in the erected buildings and structures and, äs a result, reduced operating expenses.

The use of new, efficient building materials also leads to improved quality of coiistruction owing to the fact that the new synthetic materials niay possess previously defined optimum physical and mechanical properties, precisc geoinetrical dimensions and attractive appear- ance. Production of such materials is highly industrialized and can be con~prehensively mechanized and automated.

lndustrial fabrication of new materials and units can result in a niass output of products conforming to the required standard of quality, which is a basic prerequisite for improving the quality of construction.