Fabrication and Properties of Glass Fibre Reinforced Fly Ash-Cement Roofing Tiles

In this study Glass fibre reinforced fly ash -cement roofing tiles were fabricated using three different forms of coal fly ash (CFA) such as CFA as it is, CFA particle sizes below 75μm and below 45μm.The separated CFA was used to replace cement 30% by the weight and those matrices were reinforced by Alkali Resistant (AR) glass fibres adding 1% and 2% by weight.The corrugated roof tiles have dimensions of 490×250×8mm and they were hand cast using ordinary vibration. Physical and mechanical tests were performed after 28 days of aging. The tiles were tested in accordance with SLS 1189. Transverse strength increased with increasing fibre percentage. Further, the transverse strength decreased with decreasing CFA particle size. Highest characteristic transverse strength was observed in the CFA as it is sample which is 1650N and the lowest from CFA below 45µm particle size sample which is 1240N. However, all the samples satisfy the strength requirement which is 230N. High water absorption was observed in all the samples which is around 20%.The dry density was ranged in between 1.62-1.68g/cm3 .The lowest average dry density was observed in CFA as it is samples whereas CFA below 75μm particle size and CFA below 45μm particle size samples showed similar density values. The dry density of tile samples is in comparable with the dry density of asbestos cement sheets (≈1.63g/cm3) and the characteristic transverse strength is in comparable with Calicut clay tiles (1000-2000N) in Sri Lanka. Therefore, glass fibre reinforced fly ash-cement roofing tiles are promising substitute for asbestos roofing sheets.