Lecture bld62003 mak_glass_part1
- 1. GLASS part 1 BLD62003 BUILDING MATERIALS BACHELOR OF QUANTITY SURVEYING (HONS.) BLD62003_MAK_GLASS 1
- 2. GLASS BLOCKS FORMS APPLICATION BLD62003_MAK_GLASS UNIQUENESS FACES/SURFACE TEXTURE • Often used for their decorative effect but also: • Provide controlled light transmission • Good insulation • Condensation protection • Good sound reduction • The blocks are formed of 2 cast glass shells that are fused together to form a hollow unit containing a partial vacuum. The vacuum decreases heat transmission and surface condensation. • Faces can be: • Smooth – provides vision through the block • Textured – provide only light transmission • Opaque – fired with a ceramic finish • Common sizes are 6”, 8”, 12” sq. by 4 “ thick • Mortar joints typically ¼ “ MORTAR JOINT CONCERN • Concern: glass block expands 1.5 to 2 times more than a brick wall & therefore, must have expansion joints • Usually laid in a stack bond (can only support their own weight) 2
- 4. GLASS HISTORY TIMELINE & EXAMPLE COMMON PROCESS & HAZARD BLD62003_MAK_GLASS APPLICATION COMMON GLASS & SPECIAL GLASS MINOR & MAJOR CONSTITUENT GLASS MAKING PROCESS GLASS ADDITIVE COLOR ADVANTAGES VS DISADVANTAGES EXAMPLES POTENTIAL HEALTHY& SAFETY HAZARD ROLE IN BUILDING 4
- 5. GLASS ROLE IN BUILDING BLD62003_MAK_GLASS HISTORY GLASS 5
- 7. GLASS ROLE IN BUILDING BLD62003_MAK_GLASS timeline EXAMPLE GLASS 7
- 8. GLASS GLASS, CERAMIC AND RELATED MATERIAL COMMON PROCESS & HAZARDS BLD62003_MAK_GLASS • glass • synthetic vitreous fibres • pottery • ceramic tile • industrial ceramics • brick and tiles • refractories • synthetic gems • optical fibres. • Batch raw material processes • Firing or melting processes • Material handling in production, fabrication, packaging and warehousing • Rebuilds and reconstruction activities • an inorganic product of fusion that has cooled to a rigid condition without crystallizing • When glass is cooled from the hot molten state, it gradually increases in viscosity without crystallization over a wide temperature range, until it assumes its characteristic hard, brittle form. Cooling is controlled to prevent crystallization, or high strain. DEFINITION (glass) • Glass, chemically, is actually more like a liquid, but at room temperature it is so viscous or 'sticky' it looks and feels like a solid. At higher temperatures glass gradually becomes softer and more like a liquid. It is this latter property which allows glass to be poured, blown, pressed and moulded in various shape • Glass technology has evolved for 6,000 years • A most important development in glass technology was the use of a blow pipe • The first glass was coloured because of the presence of various impurities such as oxides of iron and chromium. Virtually colourless glass was first made some 1,500 years ago. • Today many products of glass are made in fully automatic processing lines • Although glass is one of the oldest materials, its properties are unique and not yet fully understood. history • Chemistry • Pharmacy • Electrical & electronics industries • Optics industries • Construction and lighting industries application 8
- 9. GLASS COMMON GLASS Glass making BLD62003_MAK_GLASS Pot process Minor constituentMajor constituent • Silica sand • Soda ash • Lime stone • Dolomite • Feldspathic materials • Lead oxide • Boric acid • Crushed glass • The remainder of the batch consists of several additional ingredients, chosen from a group of some 15 to 20 materials commonly referred to as minor ingredients. • These latter additions are added with a view to providing some specific function or quality, such as colour, which is to be realized during the glass preparation process. • Soda-lime-silica glass (commercial glass) • Lead-potash-silica glass • Borosilicate glass • Vitreous silica • Aluminosilicate glass • Alkali-barium silicate glass • Technical glass • Glass ceramics • Opical glass • Sealing glass SPECIAL GLASS • Pot process • Tank process • The manufactured of high quality glass such as optical and mirror glass & small quantities of specialty glass • Hazard of hand shoveling & filling of the pots • Optical and specialty glasses contain heavy metals (lead, barium and manganese • Permits enclosed &continuous feeding of bath ingredient (reduced dust exposure) • Refractory blocks and bricks used in the construction of the furnaces and tanks contain free silica. tank process 9
- 10. GLASS Glass objects formed by;- Glass making BLD62003_MAK_GLASS Pot process colour ACCELERATE MELTING Glass additive • Pot process • Tank process tank process • Blowing • Pressing • Casting • Rolling • Drawing • Floating • Accelerate melting • Stabilizer • Improved optical properties • Remove bubbles • Color Fluorine Calcium fluoride Sodium silicafluoride • Increased resistance • Barium , Lead , Ca , Mg ,Zn oxides STABILIZERS COLOR • Rare earth metals • Thorium IMPROVED OPTICAL PROPERTIES • Salts of arsenic • antimony REMOVED BUBBLES • Salts of chromium ( green – yellow) • cobalt (red – blue ) • cadmium (yellow) • manganese • nickel (black) • selenium ( red) 10
- 11. colour ADVANTAGES VS DISADVANTAGES OF GLASS COMPOSITION GLASS BLD62003_MAK_GLASS 11
- 13. Laminated glass BLD62003_MAK_GLASS • Laminated glass is a type of safety glass that holds together when shattered. In the event of breaking, it is held in place by an interlayer, typically of polyvinyl butyral (PVB), between its two or more layers of glass. • The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces. • This produces a characteristic "spider web" cracking pattern when the impact is not enough to completely pierce the glass. Laminated glass OVERVIEW OF DIFFERENT TYPES OF GLASSES Laminated glass 13
- 14. TOUGHENED GLASS BLD62003_MAK_GLASS • Toughened or tempered glass is glass that has been processed by controlled thermal or chemical treatments. • It has increased strength compared with normal glass and will usually shatter into small fragments, rather than sharp shards, when broken. • Tempered glass is strong, has enhanced thermal resistance, and breaks into small cuboid fragments rather than irregular shards of glass and therefore is less likely to cause injury. TOUGHENED GLASS OVERVIEW OF DIFFERENT TYPES OF GLASSES TOUGHENED GLASS 14
- 15. FUSED GLASS BLD62003_MAK_GLASS FUSED GLASS • Fused glass is a term used to describe glass that has been fired (heat-processed) in a kiln at a range of high temperatures from 593º C (1100ºF) to 816º C (1500ºF). • There are 3 main distinctions for temperature application and the resulting effect on the glass. • Fused glass consists mainly of silica. • While the precise origins of glass fusing techniques are not known with certainty OVERVIEW OF DIFF TYPES OF GLASSES FUSED GLASS 15
- 16. MIRROR BLD62003_MAK_GLASS MIRROR • A mirror is an object with a surface that has good specular reflection; that is, it is smooth enough to form an image. • The most familiar type of mirror is the plane mirror, which has a flat surface. • Curved mirrors are also used, to produce magnified or demagnified images or focus light or simply distort the reflected image.Mirrors are most commonly used for personal grooming, decoration, and architecture. • Mirrors are also used in scientific apparatus such as telescopes and lasers, cameras, and industrial machinery. OVERVIEW OF DIFF TYPES OF GLASSES MIRROR 16
- 17. ETCHED GLASS BLD62003_MAK_GLASS ETCHED GLASS ETCHED GLASS • Etching refers to the technique of creating art on the surface of glass by applying acidic, caustic, or abrasive substances. • Glass with excellent finish to match your interiors. • Float glass is a sheet of glass made by floating molten glass on a bed of molten tin. • This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass. • Most float glass is soda-lime glass, but relatively minor quantities of specialty borosilicate and flat panel display glass are also produced using the float glass process. FLOAT GLASS FLOAT GLASS OVERVIEW OF DIFF TYPES OF GLASSES 17
- 18. OVERVIEW OF DIFF TYPES OF GLASSES STAINED GLASS BLD62003_MAK_GLASS STAINED GLASS BEVEALED GLASS • Are glass that has been coloured by adding metallic salts during its manufacture. • The coloured glass is crafted into stained glass windows in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead and supported by a rigid frame. • Painted details and yellow stain are often used to enhance the design. • The term stained glass is also applied to windows in which all the colours have been painted onto the glass and then annealed in a furnace. • Bevealed glass is usually made by taking one-quarter inch-thick clear glass and creating a one-inch bevel on one side around the entire periphery. • These beveals act as prisms in the sunlight creating an interesting color diffraction which both highlights the glasswork and provides a spectrum of colors which would ordinarily be absent in clear float glass. • "Bevealed glass" can be obtained as clusters which are arranged to create a specific design. • These can vary from simple three or four piece designs. 18
- 19. BLD62003_MAK_GLASS FRAMELESS DOOR • A liquid material is (usually) poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. • The solid casting is then ejected or broken out to complete the process. • Casting may be used to form hot liquid metals or various materials that cold set after mixing of components (such as epoxies, concrete, plaster and clay). . • Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods • Applied to :- The frameless doors include bypass, framed, frameless, and heavy glass door units. • Standard units can be customized with side panels or return panels as well as custom sizes. OVERVIEW OF DIFF TYPES OF GLASSES CASTING GLASSCASTING GLASS 19
- 20. FIGURED GLASS BLD62003_MAK_GLASS FIGURED GLASS TINTED GLASS • Figured glass is a decorative and translucent glass with figures on one face. In addition to diffusing light and obstructing visibility from the outside, the figures soften the interior lighting. • The glass used for windows in buildings, homes, and cars, while offering the advantage of letting light in, often compromises the privacy that the occupants desire, and can also let in more than the desired amount of heat. Tinted glass, however, provides an easy solution to these problems. This term refers to any glass that has been treated with a material such as a film or coating that reduces the transmission of light through it. Glass can be tinted with various types of coating, which block and/or reflect different amounts and types of light, according to the needs and preferences of the consumer. OVERVIEW OF DIFF TYPES OF GLASSES 20
- 21. GLASS (in detail) laminated toughened fused BLD62003_MAK_GLASS mirror etched float stained bevealed casting Frameless door figured tinted 21
- 23. LAMINATED GLASS DEFINITION DISPOSAL BLD62003_MAK_GLASS SPECIFICATIONS • Laminated glass is a type of safety glass that holds together when shattered. In the event of breaking, it is held in place by an interlayer, typically of polyvinyl butyral (PVB), between its two or more layers of glass. The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces. This produces a characteristic "spider web" cracking pattern when the impact is not enough to completely pierce the glass. • waste laminated glass be placed into a separating device such as a rolling mill where the glass is fragmented and the larger cullet is mechanically detached from the inner film. The application of heat then melts the laminating plastic, usually polyvinyl butyral (PVB), enabling both the glass and the interior film to be recycled. The PVB recycling process is a simple procedure of melting and reshaping it • A typical laminated makeup is 2.5 mm glass / 0.38 mm interlayer / 2.5 mm glass. This gives a final product that would be referred to as 5.38 laminated glass • for minor impact damage • using a process that involves drilling into the fractured glass to reach the lamination layer. Special clear adhesive resin is injected under pressure and then cured with ultraviolet light. When done properly, the strength and clarity is sufficiently restored for most safety related purposes. The process is widely used to repair large industrial automotive windshields where the damage does not interfere with the view of the driver REPAIR 23
- 26. TOUGHENED GLASS ADVANTAGES uses BLD62003_MAK_GLASS disadvantages • There are two main types of heat-treated glass: heat- strengthened and fully tempered. • Heat-strengthened glass is twice as strong as annealed glass while fully tempered glass has typically four to six times the strength of annealed glass and withstands heating in microwave ovens. The difference is the residual stress in the edge and glass surface. • Fully tempered glass in the US is generally rated above 65 megapascals (9,400 psi) in pressure-resistance, while heat-strengthened glass is between 40 and 55 megapascals (5,800 and 8,000 psi • must be cut to size or pressed to shape before toughening, • cannot be re-worked once toughened. • Polishing the edges or drilling holes in the glass is carried out before the toughening process starts. • used when strength, thermal resistance, and safety are important considerations. • used for side and rear windows in automobiles. • used in buildings for unframed assemblies (such as frameless glass doors), structurally loaded applications, and any other application that would become dangerous in the event of human impact. • Toughened glass can be made from annealed glass via a thermal tempering process. The glass is placed onto a roller table, taking it through a furnace that heats it above its annealing point of about 720 °C (1,328 °F). The glass is then rapidly cooled with forced air drafts while the inner portion remains free to flow for a short time. manufacturing 26
- 27. TOUGHENED GLASS ADVANTAGES uses BLD62003_MAK_GLASS • used when strength, thermal resistance, and safety are important considerations. • used for side and rear windows in automobiles. • used in buildings for unframed assemblies (such as frameless glass doors), structurally loaded applications, and any other application that would become dangerous in the event of human impact. • Toughened glass can be made from annealed glass via a thermal tempering process. The glass is placed onto a roller table, taking it through a furnace that heats it above its annealing point of about 720 °C (1,328 °F). The glass is then rapidly cooled with forced air drafts while the inner portion remains free to flow for a short time. manufacturing 27
- 30. FUSED GLASS DEFINITION TECHNIQUE BLD62003_MAK_GLASS FINISHES PRODUCT • Fused glass is glass that has been fired (heat-processed) in a kiln at a range of high temperatures from 593 °C (1,099 °F) to 816 °C (1,501 °F). There are 3 main distinctions for temperature application and the resulting effect on the glass. • Firing in the lower ranges of these temperatures 593– 677 °C (1,099–1,251 °F) is called slumping. • Firing in the middle ranges of these temperatures 677– 732 °C (1,251–1,350 °F) is considered "tack fusing". Firing the glass at the higher spectrum of this range 732– 816 °C (1,350–1,501 °F) is a "full fuse". • Fused glass techniques are generally used to create Art glass, glass tiles, and jewellery, notably beads. Slumping techniques allow the creation of larger, functional pieces like dishes, bowls, plates, and ashtrays. Producing functional pieces generally requires 2 or more separate firings, one to fuse the glass and a second slump it to shape. • stacking, or layering thin sheets of glass, often using different colors to create patterns or simple images. • The stack is then placed inside the kiln (which is almost always electric, but can be heated by gas or wood) and then heated through a series of ramps (rapid heating cycles) and soaks (holding the temperature at a specific point) until the separate pieces begin to bond together. • Once the desired effect has been achieved at the maximum desired temperature, the kiln temperature will be brought down quickly through the temperature range of 815 °C (1,499 °F) to 573 °C (1,063 °F) to avoid devitrification. • The glass is then allowed to cool slowly over a specified time, 30
- 33. DEFINITION USES BLD62003_MAK_GLASS • Mirrors are manufactured by applying a reflective coating to a suitable substrate. • The most common substrate is glass, due to its transparency, ease of fabrication, rigidity, hardness, and ability to take a smooth finish. The reflective coating is typically applied to the back surface of the glass, so that the reflecting side of the coating is protected from corrosion and accidental damage • interior decoration to create an illusion of space and amplify the apparent size of a room • A decorative reflecting sphere of thin metal-coated glass, working as a reducing wide-angle mirror, is sold as a Christmas ornament called a bauble. • Mirrors are a popular design theme in architecture, particularly with late modern and post- modernist high-rise buildings in major cities. Early examples include the Campbell Center in Dallas ART & DESIGN • Mirrors are integral parts of a solar power plant. • Telescopes and other precision instruments use front silvered or first surface mirrors, where the reflecting surface is placed on the front (or first) surface of the glass (this eliminates reflection from glass surface ordinary back mirrors have • In 2013, mirrors were installed to reflect sunlight into the town square in the Norwegian town of Rjukan.Mirrors can be used to produce enhanced lighting effects in greenhouses or conservatories. SOLAR INDUSTRY ASTRONOMYSEASONAL LIGHTING MIRROR 33
- 37. DEFINITION USES BLD62003_MAK_GLASS translucent • Translucent • Ability to soften the interior lighting • In 2013, mirrors were installed to reflect sunlight into the town square in the Norwegian town of Rjukan. Mirrors can be used to produce enhanced lighting effects in greenhouses or conservatories. PROPERTIES APPLICATION DESIGN & INSTALLATION PRECAUTION FIGURED GLASS • sheet glass that is rolled with figure or pattern on one side and that has powerful light-diffusing properties but is not transparent • Figured glass is a decorative and translucent glass with figures on one face. In addition to diffusing light and obstructing visibility from the outside, the figures soften the interior lighting. • The decorative patterns blend with a wide range of decor. ADVANTAGES & FEATURES • This glass achieves soft and comfortable interior lighting, because its figured patterns diffuse incoming light. Transmission factors for solar radiation energy and visible light rays are much the same as with float glass. decoration • It ensures privacy by obstructing visibility from the outside. privacy • Partition & interiors doors & windows • furniture • Glass with a figured surface can become dirty easily. Set with the smooth surface facing the exterior. Figured glass may become transparent if the patterns absorb water mirror in architecture 37
- 38. APPLICATIONS FIGURED GLASS FIGURED GLASS BLD62003_MAK_GLASS 38
- 40. DEFINITION BLD62003_MAK_GLASS ETCHED GLASS TECHNIQUES • Etching refers to the technique of creating art on the surface of glass by applying acidic, caustic, or abrasive substances. Traditionally this is done after glass is blown or cast, although mould-etching has replaced some forms of surface etching. • Done using hydrofluorosilic acid (H2SiF6) which, when anhydrous, is colourless. • The acid is prepared by dissolving silica in a mixture of hydrofluoric acid, quartz powder, calcium fluoride and concentrated sulfuric acid derived after heating. • Glass etching cream is used by hobbyists as it is generally easier to use than acid. Available from art supply stores, • The fluoridation of the glass causes the characteristic rough, translucent qualities of frosted glass. GLASS ETCHING CREAM • art was etched directly into the mould, so that each cast piece emerged from the mould with the image already on the surface of the glass MOULD ETCHING • Abrasive sandblasting is another common technique for creating patterns in glassware, creating a "frosted" look to the glass. ABRASIVE SANDBLASTING ACID ETCHING ETCHED GLASS I) ACID ETCHING II) GLASS ETCHING CREAM III) ABRASIVE SANDBLASTING IV) MOULD ETCHING 40
- 41. APPLICATIONS ETCHED GLASS ETCHED GLASS BLD62003_MAK_GLASS 41
- 42. APPLICATIONS ETCHED GLASS ETCHED GLASS BLD62003_MAK_GLASS 42