Durability of polymer fibres in air-cured fibre-cement roofingproducts

摘要

The physico-chemical stability of the fibres is a key element in the assessment of thernlong term durability of fibre-cement. Air cured asbestos -free fibre-cement roofingrnmaterials were developed in the early 1980's based on the use of polymer fibres.rnThese products were first introduced in European markets and are now producedrnworld-wide. In the present work, we discuss the stability of polyvinylalcohol andrnpolypropylene fibres in this context, based on recent data from accelerated ageingrnstudies as well as from natural weathering of sheets exposed in Europe and in SouthrnAmerica. It is shown, among others, that no significant change was observed inrntensile strength and in molecular weight of the fibres in products exposed for severalrnyears on roofs.