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.