PVA AND CELLULOSE PULP AS SUBSTITUTES OF ASBESTOS IN FIBRE-CEMENT FOR WATER TANKS PRODUCTION

摘要

The objective of this work was to evaluate the substitution of asbestos fibre by a combination of PVA fibres and cellulose pulp (virgin and recycled fibres) as reinforcement of cement-based matrix, for water tanks production using Magnani process in Brazil. The three-point bending test evaluated the mechanical performance. Tightness test and determination of water absorption, bulk density and apparent porosity of the material composed the physical evaluation. The warm water test investigated the possible degradation of the products as a simulation of the long-term behaviour. The residual cellulose pulps showed to be compatible with the proposed use in comparison with the virgin bleached pulp. Amongst the analysed formulations, the optimum content of PVA fibres was of 1.49% by mass (MOR = 12.4 MPa). The mechanical behaviour was considered satisfactory and no wet marks were registered in the tightness test even after 266 days of immersion in warm water.