Tuf: what are its properties?
Tuf is a natural stone that was thrown out during a volcanic eruption. It is also often composed of impurities of non-volcanic rocks. The most common deposits are located in Iceland, Italy, Armenia, the USA, Cape Verde, Kamchatka( in the Valley of Geysers), New Zealand.
Has a porous structure and is considered an excellent material for decorative finishing. It is equipped with excellent consumer characteristics, therefore it is used as the main material in construction( as a brick).We list its properties.
- Provides good thermal and sound insulation .
- High frost resistance ( about 50-600 cycles).
- Excellent water resistance .
- Resistance to various atmospheric phenomena ( not deformed).
- A small mass of , which averages 0.75-1.6 t / m3.
- It is easy to process and it fits in the process of construction work.
- Durability and strength .
Species of tuffs
If to speak in general about the varieties of tufa, then two large groups( not to be confused with volcanic tuff) stand out:
siliceous( or geyserite) and lime tuff( travertine). The first is formed after precipitation from hot sources( geysers) during the vaporization and cooling of silicon compounds on the surface of the earth.Lime tuff is deposited near natural barriers, near freshwater sources. It is formed by saturation of water with carbonic acid lime. That is why in these places you can find the presence of "cascades".Usually has a brown or orange-yellow color.
Separately it is necessary to tell about volcanic tuff which is formed at eruption of volcanoes. It contains volcanic glass, minerals( pyroxenes, feldspars), fragments of effusive rocks and some secondary formations.
Each of these types is equally suitable for both construction and finishing works. They differ from each other in the field, as well as in the physicochemical composition, which is determined at each particular source. That is, in every place( in Armenia, Italy, the USA) tuff has its own characteristics.
Scope of tufa
This material is used for interior and exterior walls. They are facing the facades of buildings and decorate the interior. This became possible due to its porous structure and variety of colors. For example, the most popular are white, orange, red, black, yellow, brown, purple, pink tuff. In the interior, it is used for decoration of fireplaces, wine cellars, walls of rest rooms.
Also this material, thanks to its hydraulic properties, is used as an additive for various mixtures( cement, mortar for plaster, including cement, air lime).Still of it make persistent paints. Separately it is necessary to say about the production of building stones and blocks.
Architectural buildings, churches and houses made of tuff are extremely warm and durable. It is easily processed( cut and sanded), which simplifies the installation process. Among the most famous buildings can be identified: the Church of the Holy Mother of God in Gyumri, the monastery complex Noravank near the gorge of the Arpa River, the Etchmiadzin Monastery in Armenia, the Lalibela Church in the north of Ethiopia. For their construction, volcanic tuff was used.
Some types of this material( better lime tuff) are used to create objects in landscape design( including reservoirs).
In addition to the aesthetic appeal of tuff, it is possible to grow all kinds of plants on its surface.