lesson 6

• Glass


  A rigid material formed by heating a mixture of dry materials to a viscous state, then cooling the ingredients fast enough to prevent a regular crystalline structure
• Engineering properties of glass

  • Transparency
  • Strength
  • Workability
  • Transmittance
  • U value
  • Recycling property
• Transparency


  The main property of glass which allows the vision of the outside world through it. The transparency of glass can be from both sides or from one side only. In one side transparency, glass behaves like a mirror from the other side.
• Strength


  Depends on the modulus of rupture value of glass. In general glass is a brittle material but by adding admixtures and laminates we can make it as more strong.
• Workability


  A glass can be molded into any shape, or it can be blown during melting. So, workability of glass is a superior property.
• Transmittance


  The visible fraction of light that passing through glass is the property of visible transmittance.
• U value


  U value represents the amount of heat transferred through glass. If a glass is said to be insulated unit then it should have lower u value.
• Recycling property


  Any glass can be 100% recyclable. It can also be used as raw material in construction industry.
• Types of glass

  • Float glass
  • Shatterproof glass
  • Laminated glass
  • Extra clean glass
  • Chromatic glass
  • Tinted glass
  • Toughened glass
  • Glass blocks
  • Glass wool
  • Insulated glazed units
• Float glass


  Manufactured from sodium silicate and calcium silicate so, it is also called as soda-lime glass.
• Shatterproof glass


  Used for windows, skylights, floors, etc. Some type of plastic polyvinyl butyral is added in its making process.
• Laminated glass


  Laminated glass is the combination of layers of ordinary glass. It has more thickness and is UV proof and soundproof.
• 
  

  Extra clean glass has two unique properties, photocatalytic and hydrophilic. it acts as stain proof and gives a beautiful appearance.
• Chromatic glassis used in ICU's, meeting rooms etc. it can control the transparent efficiency of glass and protects the interior from daylight. The chromatic glass may be photochromic
• Tinted glass


  Tinted glass is nothing but colored glass. A color producing ingredients is mixed to the normal glass mix to produce colored glass
• Toughened glass


  This is also called as tempered glass. This type of glass is used for fire-resistant doors, mobile screen protectors, etc.
• Glass blocksGlass block or glass bricks are manufactured from two different halves and they are pressed and annealed together while melting process of glass.
• 
  

  Glass wool is made of fibers of glass and acts as an insulating filler. It is fire-resistant glass.
• 
  

  Insulated glazed glass units contains a glass is separated into two or three layers by air or vacuum. They cannot allow heat through it
• Raw materials of glass products

  • Former
  • Flux
  • Stabilizer
• Former


  This is the main component of glass, which has to be heated to a very high temperature to become viscous. Silicon dioxide (contained in sand) is the most common former.
• Flux


  This is usually soda ash or potash, which was traditionally made from marine plant ashes, or by burning bracken or trees, respectively.
• Stabilizer


  Keeps the finished glass from dissolving, crumbling, or forming unwanted crystals. Calcium oxide in the form of limestone, a mineral, is a common stabilizer.
• Steps to make glass

  1. Melting and refining

  2. Float bath

  3. Coating for reflective glass

  4. Annealing- removes internal stresses

  5. Inpecting

  6. Cutting to order
• Glazing methods

  • Dry glazed
  • Wet glazed
  • Pointed support glass systems
  • Cable net
  • Double skin wall
• Dry glazed


  Structural tapes or rubber gaskets compress metal panels or glass units into frames' glazing pockets
• Wet glazed


  The wet glazed method is a method where structural silicone is applied to the aluminum frame before fitting the window panel, ideal for indoor
• Pointed support glass systems


  Pointed support glass systems, popular in buildings with views, use tempered glass with holes for bolting to structures. Despite their complexity,
• Cable net


  The cable net method offers large views and elegant design without framing, but is costly due to structural analysis and coordination.
• Double skin wall


  The most expensive and complex glazing method is the double skin method, which involves building a façade with two layers of glass, allowing for manipulation of space
• Glass repair

  1. Assessment

  2. Safety precautions

  3. Surface preparation

  4. Repair method

  5. Application

  6. Curing

  7. Finishing
• Advantages of glass

  • Transparency
  • Dustproof and waterproof
  • Aesthetically pleasing
  • Recyclable
  • UV stable
  • Weather and rust resistant
  • Insulator of electricity
  • Sustainable