Chemical resistances
The chemical resistances due to the very low concentration of free lime (less
than 1 %) surpasses that some conventional concrete matured outdoors. Indeed,
numerous mechanisms of chemical change of concretes begin with a reaction
between the not combined lime and the present acid in the water. This free lime
becomes soluble, giving porosity which disintegrates the surface. The exposed
surface increases and accelerates the corrosion. The following table gives the
acceptables values.
On the other hand, the asbestos cement pipe is incombustible and can resiste
over temperature 300ºC without degradation nor release of poison gas. The
asbestos cement does not lead the electricity (electric resistivity is of 1012
times in that of the cast iron and is not thus subject to the galvanic
corrosion nor to the current led tramps. Some of those pipes are using in
Aluminium foundery, as electrical insulator on hot gas vent.