The document discusses different types of glass, their properties, and uses. It describes glass as a versatile material that can be transparent, colored, or strengthened for various applications. Specific glass types summarized include float glass, which is made by floating molten glass and gives uniform thickness; fiberglass, which is glass reinforced plastic; laminated glass, which holds together if shattered; and safety glass like tempered glass, which crumbles instead of splintering. Overall, the document outlines the wide variety of forms glass can take and how it is used in buildings and other construction.
2. INTRODUCTION
The glass had been used as an engineering material since ancient times.
But because of the rapid progress made in the glass industry in recent
times, the glass has come out as the most versatile engineering material
of the modern times.
Glass is an amorphous (non-crystalline) solid material. Glasses are
typically brittle and optically transparent.
The use of glass in buildings is a transparent feature to allow light to enter
into rooms and floors, illuminating enclosed spaces and framing an
exterior view through a window. It is also a material for internal partitions
and external cladding.
3. Properties of Glass
1. It absorbs, refracts or transmits light.
2. It can take up a high polish and can be substituted for expensive gems.
3. It has no sharp melting point.
4. It is an excellent electrical insulator.
5. It is available in different colors.
6. It can be worked in many ways.
7. It is not usually affected by air or water.
8. It is extremely brittle.
9. It is not easily attacked by ordinary chemical agents.
10. It is possible to weld pieces of glass.
11. It is possible to alter the properties to suit different purposes.
12. Cleaning of glass is very easy.
4. Colored glass
To make colored glass, coloring pigment is added to the raw materials while
preparing the batch for its manufacture. The whole mass is heated till it becomes
homogenous.
Color Substances
1. Blue Cobalt oxide, Cupric oxide
2. Dark blue Cobalt, Manganese, and iron oxides
3. Green Ferric oxide, Chromium Sesquioxide.
4. Red Caprous oxide, Metallic gold
5. Violet Manganese dioxide
6. White opaque Tin oxide, Calcium Phosphorite
7. Yellow Antimony trisulphide, Charcoal, Silver borate.
5. Bulletproof Glass
It is made of several layers of plate glass and alternate layers of vinyl-resin plastic.
The outer layers of plate glass are made thinner then the inner layers. the
thickness of this type of glass may vary from 15mm to 75mm or more. It will not
allow bullet to pierce through it.
6. Fiberglass
Fiberglass (also called glass-reinforced
plastic, GRP, glass fiber-reinforced
plastic) is a fiber reinforced
polymer made of a plastic matrix
reinforced by fine fibers of glass.
Glass reinforced plastics are also used
for the production of roofing laminate,
door surrounds, over-door canopies,
window canopies and dormers,
chimneys, coping systems, heads with
keystones and sills. The use of fiberglass
for these applications provides for a
much faster installation and due to the
reduced weight manual handling issues
are reduced.
7. Float glass
Float glass is a sheet of glass made by floating molten glass on a bed of
molten metal, typically tin, although lead and various low melting
point alloys were used in the past. This method gives the sheet uniform
thickness and very flat surfaces.
-It consumes 30% to 40% less energy. Hence it is environment friendly.
-It is aesthetically appealing.
-It is available in large sizes and various thicknesses.
-It is economic and easy to maintain.
-It is tougher and more scratch-resistant.
-It makes the windows transmit more natural light.
-It possesses high optical clarity and superior safety properties.
Eg- Asahi, Saint-gobain.
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11. Glass blocks/Glass bricks
Glass block, also known as glass brick, is an architectural element made
from glass used in areas where privacy or visual obscuration is desired while
admitting light, such as underground parking garages, washrooms, and
municipal swimming baths. Glass block was originally developed in the
early 1900s to provide natural light in industrial factories.
Glass blocks are available in square sizes with dimensions as 150mm,
200mm, and 300mm with the approximate thickness of 100mm.
They are easy to clean and hence they can be maintained well.
They are excellent in light transmission.
They provide very good insulation against cold, heat and noise.
They possess adequate strength to carry their own weight up to a maximum
of 6m in height.
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15. Obscured glass
This glass is used at places where light is to be transmitted but vision is to be
obscured. It has one surface either ground or made opaque by melting
powdered glass upon the surface.
This type of glass is useful for public toilets, office doors, partitions, etc.
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17. Safety glass
Toughened or tempered glass is a
type of safety glass processed by
controlled thermal or chemical
treatments to increase its strength
compared with normal glass.
Tempering creates balanced internal
stresses which cause the glass, when
broken, to crumble into small granular
chunks instead of splintering into
jagged shards. The granular chunks
are less likely to cause injury.
Toughened glass is used in buildings
for unframed assemblies (such as
frameless doors), structurally-loaded
applications, and any other
application that would become
dangerous in the event of human
impact.
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20. Laminated 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.