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Performanclong sharp shards the toughenede of glass brick wall exposed to fire
Published in Paulo J.S. Cruz, Structures and Architecture: Bridging the Gap and Crossing Borders, 2019
Although the glass has been used in building industry for many centuries, its typical and traditional use was limited to window panes, taking advantage of glass transparency. However, glass has much higher potential, which was discovered recently and glass is now used in several other applications. Certainly, the transparency is the most important characteristics but high strength in tension and even higher strength in compression indicate glass can be used as a load-bearing material. Toughened glass (treated by thermal or, less common, chemical procedure) possesses by increased strength by introducing compression on the glass surface while the inner part is loaded in tension. This leads to different failure mode: while the annealed flat glass breaks into long sharp shards the toughened glass breaks into many little cube-like pieces which are less likely to cause injury. Toughened glass is used in situations when higher strength (compared to annealed glass), high level of safety and resistance to thermal shocks is required, i.e. for roofs, skylights, facades, etc.
Major accident damage repair
Published in Andrew Livesey, Alan Robinson, The Repair of Vehicle Bodies, 2018
The two basic types of safety glass used in the car windscreen are laminated and toughened. Laminated glass is of a sandwich construction and consists of two pieces of thin glass, one on either side of and firmly united to a piece of transparent reinforcing known as the interlayer. Although such a glass may crack, forming a spider’s-web pattern, it holds together and the panel remains in one piece except under conditions of the most violent impact. Toughened glass is produced by the process of heating a solid piece of glass and then rapidly cooling it so that its liability to fracture is greatly reduced and its strength increased to about six times that of untreated glass. If fracture should take place, the resulting fragments consist of very small, comparatively harmless particles.
Structural glazing
Published in Michael McEvoy, External Components, 2014
The glass used in this sort of construction has to be precisely toughened to attain a reliable strength level and to comply with BS 6206 for grade A impact strength. The maximum size of pane is governed by limitations of allowable deflection and stress in the glass as well as the available size of toughening oven, which for clear horizontally toughened glass is 4200 × 2000 mm in the UK (though larger sizes are available from continental manufacturers). These dimensions may be further modified if coated or tinted glass is required. Toughened glass is manufactured by heating and then rapidly air-cooling the glass sheets; the resulting balanced stresses built into the material make it resistant to a temperature difference of approximately 200°C between the front and back of the glass and therefore resistant to thermal shock.
Assessment of polycarbonate material as a sustainable substitute for glazing in hot climates
Published in International Journal of Sustainable Energy, 2023
Mohammed Alhaji Mohammed, Mazin M. Menkabo, Ismail M. Budaiwi
‘Glasses offer protection from natural and manmade disasters. Safety glasses used for construction are annealed, heat-strengthened, toughened, and laminated’ (Teotia and Soni 2014). Annealed Glass can be identified as the type of glass that slowly cools to relieve internal stresses; after it is formed, glass can be cut by scoring and snapping (Teotia and Soni 2014). Heat-strengthened glass has higher impact resistance and resistance to thermal stresses than annealed Glass (Teotia and Soni 2014). Fully tempered glass can also be described as toughened, which undergoes a thermal toughening process (Teotia and Soni 2014). Tempered glass is usually utilised when high-impact resistance safety glass is required in industrial locations or for commercial use. In addition, there is also laminated Glass, which consists of one or more glass panes of plastic glazing material laminated by an interlayer (Weimar and López 2018). Previously discussed glass types are specifically for panes utilised in windows or skylights, which is more related to the impact resistance property of glass rather than thermal insulation. Therefore, the types of glass that are usually applicable to windows or skylights, which focus on thermal insulation, directly impact building energy consumption. One of the famous window glazing types is doubled glazed window, which reduces energy consumption compared to a single-glazed window by improving the material’s insulating properties via the provided air gap between the panes as a thermal barrier [(Aguilar-Santana et al. 2020) as cited in 22]. Another window type is the triple-glazed window system, which reduces thermal transmittance due to its additional insulation, making it more advanced in thermal transmittance. The triple-glazed fenestration system allows less solar heat gain than a double-glazed window (Hee et al. 2015). “Another factor that makes three-layer glazed superior is its thickness, which decreases the thermal conductivity of the window as the window layer increases” (Hee et al. 2015).