Different ageing conditions on cementitious roofing tiles reinforced with alternative vegetable and synthetic fibres

Abstract

This paper discusses the effects of different ageing conditions on the mechanical and physical characteristics of cementitious roofing tiles reinforced with sisal and newsprint pulps, sisal strand fibre and polypropylene (PP) fibre. Roofing tiles with undulate shape were produced by a slurry de-watering and pressing technique. They were subjected to three distinct ageing conditions: fast carbonation, accelerated ageing cycles and fast carbonation plus accelerated ageing cycles. Fast carbonation did not improve the maximum load (ML), limit of proportionality (LOP), toughness and maximum deflection but did decrease their water absorption, apparent porosity and air permeability; however, after 50 heat and rain accelerated ageing cycles, it was ineffective in maintaining the mechanical properties (ML, LOP, toughness and deflection) of the tiles reinforced with vegetable fibres. The refined sisal pulp fibres led to roofing tiles with slightly higher LOP, toughness and maximum deflection than those reinforced with newsprint pulp fibres. PP fibres significantly improved the mechanical performance (ML, LOP, toughness and deflection) of the roofing tiles in relation to sisal strand fibres. The accelerated ageing cycles were effective in promoting severe degradation on the roofing tiles with sisal strand fibres, while the tiles reinforced with PP fibres were practically unaffected.