Products
Only high-density chrysotile products are manufactured and sold today. The unique feature of these products is that the chrysotile fibre is encapsulated in a matrix of cement or resin, preventing the release of fibres. Over 90% of chrysotile used worldwide today is in the manufacture of fibre-cement building and construction materials.
| Asbestos uses |
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Before |
Now |
| Products |
Asbestos-cement
Friction
Insulation
Textiles
Low density |
Chrysotile-cement
Friction
High density |
| Fibre types |
Chrysotile
Amosite
Crocidolite |
Chrysotile |
Chrysotile-cement products (C/C)
Chrysotile has been used for a long time, as well its rough state as added to various products. Why adding chrysotile to cement? Quite simply to make it more resistant, lighter, and to improve its commercial and industrial lifespan.
Chrysocement exists since the beginning of the 20th century. It was invented in Austria in 1904, and was largely used for residential and agricultural construction in Europe during last century, mainly after the Second world war. A large majority of the few 25 million tons of chrysotile, which were imported by the European countries between 1950 and 1995, served this purpose
More than 90% of the world production of chrysotile is used in the manufacture of chrysotile-cement, in the form of pipes, sheets and shingles. These products are used in some sixty industrialized and developing countries. Chrysotile-cement is valued principally for its excellent cost effectiveness and durability. Manufacture of this material requires the import of only small quantities of fibre, the other raw materials being easily available locally. Moreover, the manufacturing technology requires little investment and consumes less energy than production methods for competing products.
The most popular chrysocement product is undoubtedly the rigid or corrugated sheets used for roofing in developing country. Some companies also choose to cover their roof with shingles made of chrysocement; they are offered in various colours just like the shingles being used to cover the walls. Chrysocement is also used to manufacture various products for the transport and the conservation of all kinds of water, like pipes, sewers and water tanks.
Chrysotile finds several uses in cement. It allows cement to last a minimum of 50 years, at lower cost. A study carried out in 1996 indicates that to cover 1000 square meters of roof resisting 50 years, one needed 16 780 kg of sheets of chrysocement or 14 770 kg of polyvinyl alcohol fibre sheets (PVA) or 10 085 kg of steel sheets (lasting 35 years with a high degree of maintenance). Despite the fact that one needs a little less PVA than chrysocement to cover the same surface, the study shows that over one 50 years period the environmental impact of chrysocement will be two to six times lower than the PVA. Compared with steel, chrysociment also has a lower environmental impact, unless the steel sheets have a recycling rate higher than 80 %. Chrysocement is the cheapest product by far among all asbestos cement materials offered on the world market.
All things considered, chrysocement is an excellent produced, both for the economy the environment.
Chryso-asphalt products
Driving on chrysotile? It is possible and extremely probable, because a considerable number of roads of Quebec have been covered with asphalt containing chrysotile since 1917. And contrary to some people still believe today, asphalt containing chrysotile (approximately 1,5 %) does not release significant quantity of fibres in the environment. It is useless and ridiculous to think that living close to the road containing chrysotile will cause death. It would be more logical to fear the emanations released by the cars circulating on these roads.
Why adding chrysotile fibres in asphalt? Simply because these fibres increase wear resistance (the cracks and rutting), without loss of stability. It also increases the flexibility and frost resistance of the asphalt. Despite the fact that the costs of implementation are a little higher (approximately 5%), all things considered, chrysotile fibres confer impermeability, flexibility and strength to the asphalt. It represents an ideal solution for roads having an important flow of circulation. As the durability of this coating can reach the double of the traditional coatings, the increase of cost is easily absorbed over the lifespan of the road and represents substantial economies for the taxpayers.
To add chrysotile to bitumen, the technique is quite simple. First, one has to pour, in the mixture, the chrysotile fibre bags especially conceived for this use. The bags of plastic will melt in the bitumen carried at high temperature, thus avoiding the risk of fibres releasing in the air. Thereafter, once the aggregates are introduced into the mixture, it is time to apply the asphalt on the road. Please note that recent data show that the installation of chryso-asphalt is without danger for the health of the workers; the fibres release in the air naturally does not exceed the level present in the environment. Even in situations known as extreme and not very probable (dry scarification), chrysotile fibres release in the air are five times lower than the standard prescribed by the World Health Organization, which is 1 fibre/cc.
Friction materials (F/M)
Because of its natural resistance to heat, chrysotile fibres have been widely used in friction materials. Automobile brake shoes, disk pads, clutches and elevators brakes are common examples of products using chrysotile fibre.
Other products
As reported in several books, chrysotile was used in the manufacturing of some 3000 products. The reality today is simpler, but there is still a significant variety of common-day and industrial uses of chrysotile containing products. For example, chrysotile fibre is used in roof sealants, textiles, plastics, rubbers, door seals for furnaces, high temperature caulking, paper, components for the military and the nuclear industry.
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