Performance of natural fibre reinforced mortar roofing tiles

Interest in natural fibres as reinforcement in developing countries arose (when the use of steel and glass fibres in the industrialized countries was being researched and developed in the late 1960s) mostly because of their lower cost and better availability in the developing world. The use of natural fibres as reinforcement for mortar to be used mainly for roofing has been debated for a long time. Initially, it was rightly thought that natural fibres will adversely affect the setting of Portland cement and as such they should not be used. Later on it was found that natural fibres are embrittled by the hydration products of Portland cement and made ineffective within a short time, especially in hot climates. While such discussions were going on, the initially adopted large corrugated roofing sheet (corrugated iron sheet size) was being found impractical (mainly because of handling and curing problems) and its size was being reduced gradually. The present paper discusses difficulties encountered in the production and use of natural fibre reinforced mortar roofing tiles and means of reducing the adverse effects of Portland cement hydration products on the performance of natural fibres in mortar.