What is Glass?

Glass is an amorphous substance having homogeneous texture. It is a hard, brittle, transparent or translucent material. It is the most common material glazed into frames for doors, windows and curtain walls. The most common types used in building construction are sheet, plate, laminated, insulating, tempered, wired and patterned glass. Most ordinary colourless glasses are alkali-lime silicate and alkali-lead silicate with tensile and compressive strengths of about 30–60 N/mm2 and 700–1000N/mm2, respectively and modulus of elasticity in the range 0.45 × 105 to 0.8 × 105 N/mm2 . The strength is very much afftected by internal defects, cords and foreign intrusions. The main shortcoming of glass is its brittleness which depends on a number of factors, the chief one being the ratio of the modulus of elasticity of the material to its tensile strength.