8.2. Glass products in construction

Construction glass is divided into sheet glass and products of the architectural-construction assignment.

Sheet glass. The range of sheet glass is various (Table 8.3): plate glass, figured and reinforced, with the special properties, that skips and takes in ultraviolet rays, with semi-transparent mirror coverage, which takes in or beats back warmth, electro- lead, treated by hardening.

Table 8.3

Basic types of sheet glass

Type of glass	Thickness, mm	Recommended industry of application
Mirror improved glass	2…6	Producing of high-quality mirrors
Mirror glass	2…6	Producing of mirrors of the general assignment
Technical polished glass	2…6	Producing of decorative mirrors, safe glasses of transport vehicles
Window-pane glass polished	2…6	High-quality glazing of light transparent constructions
Window-pane glass unpolished	2…6	Glazing of light transparent constructions, safe glasses for agricultural machines
Plate glass polished	6,5…12	High-quality glazing of windows, stained-glass windows
Plate glass unpolished	6,5…12	Glazing of windows, stained-glass windows

Sheet glass has high coefficient of optical transmission, wide range of values of linear sizes and thickness.

A window-pane is divided into sorts depending on the presence of defects: striped, crinkles, bubbles, other impurities and scratches.

For glazing of large surfaces of buildings large size window glass are used, that produce as unpolished and polished, in order to avoid optical distortions.

Glass packs are applied for prevention from damping and freezing of glass, and also for the cutback of labor consumption and use of industrial methods at glazing of window cuts. They consist of two or few flat glasses, connected by welding or agglutination. Between them appears reserved space in thick 15...20 mm, filled with dry air (Fig 8.1). In the case of the glass packs use, heat-insulation and sound-proofing are improved.

I f it is required to avoid transparency of the light openings or glass partitions, then the figured glass is applied. This glass has light-diffusing ability, is decorative and enables to create expressive interiors, especially in buildings of the cultural and medical purpose. It is produced colorless and colored.

A wire mesh is squeezed in glass for content of fragments at the damage of it. R einforced glass is used for finishing of lanterns, construction of partitions and arranging of protections of balconies, where enhanceable mechanical strength of material is required.

Reinforced glass as well as figured, is produced colored and colorless. Colorless glass is applied mainly for glazing of the light openings, and colored - in the protection of balconies, for arranging of internal partitions. The surface of reinforced glass can be smooth, corrugated, figured. To promote mechanical strength of glass, it is hardened.

Tempered sheet glass is used for production of glass doors, protections of balconies and steps, elevator shafts. Safe character of destruction is peculiar to this type of glass. The possible overfall of temperatures during exploitation reaches 270°C. Value of bending strength is in 5.5 and compressive strength in 1.35 times higher, than in ordinary window-pane. Tempered glass is not subjected to cutting, drilling and other types of tooling. Painted by the colored ceramic fusible paints tempered sheet glass is applied for revetment of buildings facades.

Unlike ordinary glass the special uviol glass passes biologically active ultraviolet rays. It is produced from particularly pure materials, containing no more than 0.03 % iron oxides. To achieve maximal effect, uviol glass with minimum possible thickness is applied. Ability of passing ultraviolet radiation recommences, when uviol glass is heated to 300...450°C. Uviol glass is applied for glazing of windows in child's and medical establishments, in buildings of the health resort purpose. It is desirable to apply glasses absorbing ultraviolet rays, in libraries, museums, art galleries, which influence on quality of paper, fabrics, paints, varnishes and others like that. Oxides of chrome, selenium, vanadium are added in particular to the complement of glass for this purpose, the painted glass with oxide-metallic coating is also used.

Glass with semi-transparent mirror coating is used for the external glazing. Colored and colorless mirror coatings get causing on glass of films of oxides of titan, iron, cobalt, copper. Glazing with the painted glasses is applied in buildings with the large areas of glazing to avoid overheat of apartments. Neutral glasses reduce transmission in all optical range of sun spectrum. Glass, painted by the oxides of iron, zinc, copper and other metals, or glass with superficial pellicle oxide-metallic coatings has an ability to heat absorption. They are set in the external row of glass packs and for intensive heat removal provide required ventilation. Elastic putties and rubber seals are applied for the removal of undesirable tensions.

Glass products. Promoting of strength and longevity of light transparent protections, decreasing the amount of wood and metal, improving operating qualities of glazing is possible by the hollow and profile types of glass. These products are intended for filling of the various light openings, arranging of external and internal light filter protections in buildings and structures of different destination.

Glass blocks are produced rectangular (they can be also round and angular) from colorless or painted glass. The surface of facial walls of transparent glass blocks is smooth, light-diffusing - corrugated, what eliminates visibility. Glass blocks should have value of compressive strength not less than 1.5 MPa, resistance to the shock action – 0.8 MPa.

Structures from glass blocks form the soft diffused lighting and have enhanceable heat-insulation and sound-proofing.

E nclosures from glass blocks (Fig. 8.2) are arranged directly in window opening (without establishment of frame) on cement-sand mortar or installed the glass reinforced concrete panels made in advance. Such panels due to structural peculiarities and production technology are similar to the combined reinforced concrete structures. They can be installed in window openings in place of the double glazing. Taking into account the considerable coefficient of thermal expansion, glass reinforced concrete panels are insulated from load-bearing panels with compensative joints, filled by elastic gaskets.

Structural glass is profiled glass with channel, box-like or other section (Fig. 8.3). Due to large overall dimensions (length up to 8 m) at installation profile glass there is no necessity to apply intermediate frames.

For the improvement of light-diffusing ability and original appearance the surface of glass from the side of cavity is executed as corrugated. Structural glass is reinforced with a steel wire, as a result its fire-resistance rises, and at destruction fragments do not fly away. Value of bending strength for structural glass exceeds 10 MPa, optical transmission is 60...80%. For compression and sealing of joints between the elements of structural glass various polymeric mastics and porous gaskets are used.

Enclosing structures from structural glass, which are erected from the precast panels of factory-made, are the most perspective. Such panels consist of frame, made of wood, concrete or metal, and filling - structural glass.

Glass pipes are intended for construction of pipelines, which transport chemically aggressive liquids, gases, food products, friable and other materials. They perform in the conditions of temperature overfall 40...80°С and working pressure 0.2...0.7 MРa. The diameter of glass pipes achieves to 2000 mm, length – 1.5..3.0 m. They are not subjected to corrosion, their carrying capacity is higher, than cast-iron and steel pipes at an identical internal friction. They are used also for the gasket of electric wiring, making of the heated panels and others like that. Basic lack of glass pipes is limited impact resistance.

High chemical resistance of glass and mechanical strength of steel are combined in steel pipes, lined with glass. Considerably promoting strength of glass pipes is possible, covering them with a layer of fiberglass plastic.

F lags from marbled glass - opaque painted glass with the polished surface are used as facing material. Marbled glass has marble-alike structure. A reverse side is executed as corrugated or rough. Marbled glass is produced by rolling from wastes of glass, with additive of metallurgical slag. Sizes of flags are 250×140 and 500×500 mm, sheets-200×3000 mm, thickness -5...12 mm. Profiled elements are also made from marbled glass.

Similar to marbled glass due to structure and properties are synthetic granite, glass- marble, glass crystallite and other facing materials.

Glass crystallite - double-layer material, the facial surface of which is smooth, polished, coloured imitates ornamental stones, underlayer is rough, provides reliable adhesion with cement-sand mortar. For the decline of density of flags in the underlayer of glass crystallite gas-forming admixture is included.

Carpet-mosaic glass tiles are used for external revetment of walls (except for basements and cornices), internal finishing of walls and columns, making of decorative- artistic panels. It is obtained from opaque and semi- opaque glass by rolling. Tile is supplying in carpets, glued on a paper. After steam curing the facade side of panel is cleaned from a paper and glue.

The enameled glass tiles are cuted from sheet glass (as a rule, from wastes). One of surfaces of tile is covered by the coloured or white enamel. Tiles are applied for interior walls tiling of the buildings with enhanceable sanitary-hygienic requirements.

Facing glass tiles also can be manufactured by pressing from opaque glass mass or glass scrap. Reverse surface of tiles is made as corrugated for the best bond it with mortar.

Smalt - pieces of the stained opaque glass of various form, which are collected in carpets on a paper. They are used for the decorative finishing of buildings and structures, implementation of the mosaic works.

The basic component of large group of materials is fibreglass. Depending on length of filaments fiberglass is divided into continuous and staple (length to 30 cm). Due to diameter a fiberglass can be: ultrafine <1; superfine – 1...2; fine – 3…10; incrassate – 11…20; thick – over 20 m. Ultra-, super and fine fiberglasses have so high flexibility that can be processed by textile technology. Their tensile strength is 200...500 MPa, it grows to the extent of diminishing of diameter. Electric insulating ribbons and fabrics, heat-insulated and sound-proof glass cotton wool, and also plait, nets and linen are produced from fibreglass.

Linen is applied for reinforcing of various waterproofing materials and for manufacturing of fiberglass plastic.

Glass-fibre materials are used effectively for protecting from the silting-up of the drainage systems. They differ by good filtration properties, longevity and resistance in aggressive subsoil water. Polyvinyl acetate emulsion serves for glass linen as binder. Filtration ability of glass linen in mineral soils is saved for long time. Glass cloth has considerably less water permeability, than glass linen and more subjected to the influence of mudding. They are recommended for application only in sandy soils.

It is important to execute the special safety measures at transporting and keeping glass and glass products. Glass is folded in wooden boxes or containers and interlaied with the wood shaving or corrugated paper.