GLASSBedevere Joseph Abais

Kristianne AngFrancine Cayanan

Patrick Flores2AR-9

GLASS

Glass plays an essential role in the facade. A facade is a special type of wall. It separates inside from outside.

Glass is a uniform material, a solidified liquid. By its property of transparency it opens up our buildings to

the outside world. In modern architecture there is tendency to open up our buildings by using very large

facades that are as transparent as possible.

In the external wall, glass can be used as a curtain wall or structural glazing.

Glass is not essentially transparent. They are available in several opacities and various textures and finishes.

HOW WAS GLASS DISCOVERED?

According to ancient-Roman historian Pliny (AD 23-79):o First discovered in Mesopotamia by

Phoenician Merchants.o Landed on a beach in Syriao Propped a cooking pot on some blocks of

Nitre (Potassium Nitrate) placed by their fire.

o Due to the heat of the fire, the blocks melted and mixed with the sand of the beach creating melted glass.

CHARACTERISTICS OF GLASS

If heated it softens, melts and becomes a thick syrupy liquid making it possible to be bent.

Can be blown, drawn, rolled, pressed and cast into a variety of shapes and textures during in its molten state.

Commonly used to glaze window, sash and skylight openings in buildings.

Breaks easily Waterproof

COMPOSITION

Glass is made from the following raw materials: Silica (S2O2) 71.0 to 78.0% Alumina (Al2O3) 0.5 to 1.5% Iron oxide (Fe203) 0.05 to 0.15% Calcium oxide (CaO) 5.0 to 10.0% Magnesium oxide (MgO) 2.0 to 5.0% Sodium oxide (Na2O) 13.0 to 16.0% Potassium oxide (K2O) 0.0 to 1.0% Sulphur trioxide (SO3) 0.0 to 0.5%

TYPES OF GLASS

Laminated Glass Toughened Glass Wired Glass Reflective Glass Flat Glass Patterned Glass Glass Brick Tinted Glass Chemically Strengthened Glass Low Emissivity Self-Cleaning Glass

LAMINATED GLASS

A type of glass that holds together when shattered

In the event of breaking, it is held in place by an interlayer, typically polyvinyl butyral (PVB) between its two or more layers of glass.

This produces a characteristic “spider web” cracking pattern when the impact is not enough to completely pierce the glass.

Usually used for skylight and automobile windshields.

TOUGHENED GLASS

Also known as Tempered Glass. A glass that has been processed by

controlled thermal or chemical treatments Has increased strength and enhanced

thermal resistance compared with normal glass and will usually shatter into small fragments, rather than sharp shards when broken and therefore is less likely to cause injury.

Usually used for automobile side and rear windows, skylights, frameless glass door

FRAMELESS DOORS

WIRED GLASS

A type of glass into which a wire mesh is embedded during production.

Manufactured primarily as a fire retardant, with wire mesh inlaid in the glass to prevent it from shattering and breaking out under stress or when exposed to high temperatures. In case of breakage, the mesh retains the pieces of glass.

Can be tinted by aerosol or electricity.

REFLECTIVE GLASS

Coating of a metal compound applied on one surface by chemical deposition.

Reflects light and solar heat May be applied on any type of glass and

thickness upto half an inch Uses: principally used in curtain wall glazing

and structural glazing, train windows(AC compartments), doors and windows of commercial buildings, partitions and internal wall cladding.

Disadvantages: Causes light pollution and is hazardous to traffic.

FLAT GLASS

Flat glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass process. The flat glass process is also known as the Pilkington process, named after the British glass manufacturer Pilkington, Alastair Pilkington pioneered the technique in the 1950s.

PATTERNED GLASS

Sometimes referred to as “figured” or “rolled” glass. Has a pattern or texture impressed on one or both sides

in the process of rolling.  This glass surface has a patterned decorative design

which provide translucency and some degrees of obscurity.

 Patterns are classified as decorative or glazing Uses:  decorative glazing of windows, bathroom

partitions, door. Is difficult to clean as dust settles between the crevices Thickness: 4mm, 6mm,  Sizes: 2140 x 1280 mm, 2140 x 1320 mm respectively.

GLASS BRICK

Also known as glass block, is an architectural element made from glass. Glass bricks provide visual obscuration while admitting light.

Glass bricks are produced for both wall and floor applications.

Use in floors are manufactured as a single solid piece, or as a hollow glass block with thicker side walls than the standard wall blocks.

Hollow glass wall blocks are manufactured as two separate halves and, whilst the glass is still molten, the two pieces are pressed together and annealed.

CONSTRUCTION METHOD

To bed the blocks together in a Portland cement-based mortar with reinforcing rods of steel placed within the mortar.

Other methods of construction include several proprietary systems whereby the mortar is replaced by timber or PVC extrusions.

SPECIAL TYPES

Bullet and vandal resistance-Bullet and vandal resistant blocks are generally solid glass or have very thick side walls similar to pavement blocks.

Fire resistance -Resistance is improved by utilizing specially produced hollow blocks with thicker sidewalls, or the inclusion of a special layer of fire resisting material between the two halves of the block during manufacture.

Gas insulated-Inclusion of argon gas within the hollow center of glass wall blocks offers significantly improved thermal insulation properties.

Colored-Some hollow glass wall blocks are available in colored variants. These colored variants fall into two categories; those that are manufactured with colored glass which are UV stable and can be used in the same locations as standard clear glass blocks.

TINTED GLASS

Body tinted glass products are produced by small additions of metal oxides to the float or rolled glass composition.

These small additions color the glass bronze, - selenium oxide green, - iron oxidegrey – cobalt oxideblue - additional cobalt oxide

but do not affect the basic properties of the glass except for

changes in the solar energy transmittance. The color is homogeneous throughout the thickness. 

weak colors by transmitted light. They do not produce high or significantly colored reflectances. Usually their principal external visual characteristic is their lower light transmittance. 

INSULATED GLAZING

Insulated glazing (IG), more commonly known as double glazing (or double-pane, and increasingly triple glazing/pane) is double or triple glass window panes separated by a vacuum or other gas filled space to reduce heat transfer across a part of the building envelope.

Insulated glass units are manufactured with glass in range of thickness from 3 mm to 10 mm (1/8" to 3/8") or more in special applications. Laminated or tempered glass may also be used as part of the construction. Most units are manufactured with the same thickness of glass used on both panes but special applications such as acoustic attenuation or security may require wide ranges of thicknesses to be incorporated in the same unit.

CHEMICAL STRENGTHENED GLASS

These are glass products that have been strengthened by means of an ion-exchange process.

typically six to eight times the strength of float glass.

Glass is submersed in a bath containing a potassium salt at 300°C. This causes sodium ions in the glass surface to be replaced by potassium ions from the bath solution.

LOW EMISSIVITY Thin film coatings are applied to the raw soda-lime glass, to improve thermal efficiency (insulation properties)

Coatings are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow.

 Two primary methods in use: pyrolytic CVD and magnetron sputtering..

The first involves deposition of fluorinated tin oxide at high temperature. Pyrolytic coatings are usually applied at the float glass plant when the glass is manufactured.

The second involves depositing thin silver layers with antireflection layers. Magnetron sputtering uses large vacuum chambers with multiple deposition chambers depositing 5 to 10 or more layers in succession.

SELF-CLEANING GLASS

 Is a specific type of glass with a surface that keeps itself free of dirt and grime.

The glass cleans itself in two stages. The ‘photo catalytic’ stage of the process

breaks down the organic dirt on the glass using ultraviolet in sunlight (even on the overcast days) and makes the glass hydrophilic (normally the glass is hydrophilic). During the following ‘hydrophilic’ stage rain washes away the dirt-leaving almost no streaks, because hydrophilic glass spreads the water evenly over its surface.