Glass

GLASS

Glass Building Material is a mixture of raw materials like silica, sodium potassium carbonate, lime or lead oxide, manganese oxide which are grounded, sieved, and mixed in specific proportion to make glass. It is one of the oldest & multifaceted materials utilizing in the building industry. Glass has been used to enhance the aesthetic view of structure and is fascinating material ever since it was discovered. It is an open hard substance created by giving heat to sand or quartz, glass forms an inorganic, transparent, or translucent material which can be molded into any shape. It is a transparent glazing material, providing the architect's new designs and possibilities to enhance the look and features of the building. It adds beauty & elegance to the look and feel of the structure, and is one of the most versatile materials to be used in the construction industry.

PROPERTIES OF GLASS

Glass has main engineering properties due to which the utilization has become vast in construction industries;

❖ U Value: This represents how much heat is transferred through the glass. Insulated glass units provide a low U value.

❖ Transparency: Transparency is the main and primary engineering property of glass that allows us to see through it. Due to this property glass can be transparent from both sides or from one side only and the other side acts like a mirror.

❖ Work-ability and Recycle Property: Glass has superior workability as it can be molded into countless shapes or blown during melting. Also, any type of glass can be 100% recyclable and used as a raw material in construction.

❖ Strength: Glass's strength is measured by its modulus of rupture value. Glass is generally brittle or tends to break easily but we can make it stronger by adding admixtures and laminates.

❖ Transmittance: This property of glass refers the visible fraction of light passing through the glass.

TYPES OF GLASS

The different types of glass used in construction industries are described below:

❖ Sheet glass is produced by having molten glass pass through the rollers to manufacture a nearly flat finish. It can be cut using a glass cutter and no special equipment is needed. It's generally available in the market in a range of standard sizes/thicknesses. Due to the comparatively low cost of this glass and its lack of distortion, flat sheet glass is mainly used in glazing greenhouses and where the visual distortion isn't an issue as opposed to domestic windows, etc.

❖ Float glass: It is made from sodium silicate and calcium silicate, it is also known as soda-lime glass. The "Float" name suggests the method used to manufacture it, where the molten glass is floated onto a bed of molten tin. This gives us a flat, clear, distortion-free glass. Float glass can be cut  with a special thin coating on one side. This glazing allows solar energy to pass through in only one Construction Materials and Technology- by utilizing a glass cutter without a need for special equipment. It is available in thickness ranging from 2mm to 20mm, with a weight ranging from 6 to 36 kg/m2. The functions of this type of glass include fixed & opening windows above waist height, shop fronts, as well as in public places.

❖ Laminated Glass: As the name refers, this glass comprises layers of ordinary glass bonded by a transparent, flexible material. As it is a sandwich made up of two or more sheets of glass. This type of glass is commonly UV and soundproof, which explains its applications in the construction of bridges and aquariums. It is mostly the best suited for making glass canopies as it can reduce harmful rays. This glass comprising of 2 sheets of toughened glass and a laminate in the middle portion. This is typically 6mm toughened / 2.28mm laminate / 6mm toughened.

❖ Toughened glass is used extensively throughout the industry for its ability to resist breaking, also called safety or tempered glass. If it breaks, it does so into much smaller called 'safer' pieces as opposed to large shards. Toughened glass is typically used in home interiors such as the kitchen and shower screens, glass balustrade, and swimming pool fencing. It can also be utilized in laminated panels where extra safety precautions should be taken.

❖ Shatterproof glass is a type of glass that is resistant to shattering. In other words, it doesn't break into pieces in the event of destruction. Making up of shatterproof glass includes the addition of a plastic polyvinyl butyral resin to prevent it from forming sharp pieces. It is commonly used in windows, floors, and skylights.

❖ Energy efficient glass: This type of glass building material is manufactured by glazing float glass with a special thin coating on one side. This glazing allows solar energy to pass through in only one direction while minimizing the transfer of thermal energy in the other direction.

❖ Wired glass: In this type of glass a wire mesh is provided in the middle portion of the structure of glass. The main objective of the wire is to hold the glass together in the event of cracking or breaking, however, it doesn't stop the glass from forming sharp pieces when broken. Wired glass is available as clear or obscured, wired glass is generally used in more industrial areas or structures such as garages.

❖ Tinted glass: It is a simply colored glass. A certain type of ion is added to the normal glass mix to produce colored glass. In tinted glass, color doesn't affect the properties of glass. For example, iron oxide gives green and Sulphur gives blue color shades in glass manufacturing.

DISADVANTAGES OF GLASS

Some of the drawbacks of glass are narrated below:

❖ Cost is High: The manufacturing of glass is a highly energy-consuming process due to the high temperatures required for processing the raw materials. Using glass in a building increases the total cost of security & privacy because of the transparency that it offers.

❖ Brittleness: Glass is a stiff, rigid, and brittle material. When glass is subjected to stress, it fails/breaks without any significant strain. Cracked pieces of glass may be very sharp, and the chances of injury to humans become very high.

❖ Impact Resistant is Low: The Glass is less resistant against impact load, so the capability of the glass to withstand an immediately applied load is very poor. It will immediately break under impact.

❖ Corrosion due to Alkali Solution: The Glass is affected by alkalis ions. Alkali solution dilutes a glass surface, and if the supply of alkali is more, this type of corrosion takes place at a uniform rate.

❖ Unsafe for Earthquake-prone Areas: Structures that are located in earthquake-prone areas require to be specially designed to take horizontal loads and movements. The material of glass is more brittle than other material, hence it tends to break or collapse quickly.

❖ Maintenance Cost is High: In more dust-prone regions & humid areas, dust particles will stick to the glass surface and hence it will not only look dirty and shabby but the internal lighting, as well as transparency, will be poor.