How is the durability of glass?
Many friends are curious about the durability of glass. In fact, the ancient churches in most cities can witness the durability of glass. Especially modern glass production is quite uniform and performance constraints. Generally, in addition to mechanical stress, there are only a few factors that damage glass, and durability can be said to be very good.
Abrasion will cause the glass to scratch and remove any exposed coatings. Sand in the wind may be a natural phenomenon, but it is rare, which causes significant damage. Most examples of damaged architectural glass are the effects of processing up to and including glass and thereafter, following deals. Unless the glass surface protection is finally cleaned down it can reveal cement and gypsum products deposits. The product has a spatula or grit that attempts to remove the cleaning cloth can cause wear to be picked up.
Chemical attacks are also not a common natural event. Clean fresh water is not glass, but the threat of acid rain can have long-term effects. Glass is good at resisting most acids with short-term exposure. Alkali products can attack the chemical composition of the glass surface. Salt and alkali are found in cement, so contamination in glass buildings can cause damage unless it is removed immediately. New glass work from the entire glass or concrete water runoff can also be manifested on glass surfaces that contain enough alkaline chemicals to cause attacks.
Pitting of glass can be caused by welding slag from tools used on construction sites. Hot particles either fuse to the surface of the glass or fall off leaving pits. Old glass, pre-modern mass production, may show signs of pitting due to years of exposure to water. The chemical composition of glass has a balance between the properties required of the product sought-resistance to chemical attack, strength, melting temperature and hardness (workability).
In the strength of glass, we discuss its unusual properties. The durability in terms of mechanical strength is variable. The theoretical strength of glass is very high, but we cannot achieve full strength. Made from glass at the moment it is made by machinery and so on. That affects the surface of the glass to be treated in a way that is invisible to the individual eye. Minor imperfections on the surface allow stress loading and the glass breaks down from the defect so concentratedly. The lack of resistance to breakthrough means that the crack can grow until it is obvious. In our calculations, we allow the effects of defects and design around the lowest intensity.
Article Source：www.glass.cn 2020.01.08
