Environmentally friendly vege-roofing tile: an investigation study

Abstract

This paper presents a research study conducted on the usage of vegetable oil as a binder for roofing tile. Conventionally the roofing tiles used by construction industry are either concrete or clay roofing tiles in which cement and heat curing is used as a binder. Both of these material types utilize a large amount of energy for their manufacture, making it environmentally unfriendly because of high content of CO2 emission during its production. To cater this problem, a novel methodology of producing roofing tiles with vegetable oil (palm oil) is used in this study, as it does not require the use of any form of cementitious or pozzolanic materials or water. These manufactured tiles would be considered more environmentally friendly than cementitious and kiln manufactured tiles, both of which are high energy consumers. Limited trails were conducted and it was found that when a pre-determined amount of vegetable-oil was blended with graded mineral aggregates (river & mining sand) with fly ash as filler and then compacted into moulds, subsequently heat cured in oven for durations ranging from 6 to 10 days have shown flexible strength up to 23MPa. The achievement of strength is dependent on mix proportions and tile dimensions. It was observed that curing resulted in complex autocatalytic oxy-polymerization set of reactions which converted the vegetable oil into a rigid solid binder. All prototype samples were tested for water absorption, permeability and flexural strength according to ASTM Standards. The results obtained from prototype sample (15mm x 100mm) prepared with 50% and 35% filler achieved the flexural strength up to 23MPa and 21MPa respectively when cured at 190oC.