The final disposal route of post-consumer recycled glass (RG) is a common issue for many municipalities worldwide. Approximately 1 million tons of glassware is produced per year in Brazil, only 47% of which are currently recycled. The idea of incorporating RG as aggregate for concrete emerged in the 60’s motivated by some of the advantages of glass, i.e. low water absorption, high abrasion and durability aesthetic potential among others. However, the initial researches have shown that concretes containing RG exhibited marked strength regression and excessive expansion due to alkali-aggregate reaction (ASR), which limited further research The topic emerged again in the 90’s, imposed by the sustainability issues. Moreover new studies aimed to determine the conditions at which ASR does not occur, as well as the influence of RG on the physical properties of concrete. Despite some literature on the use of RG into concrete, its application for making concrete roof tiles is still not documented. The incorporation of RG into those products, if feasible, may create a sustainable material for construction by reducing the land-filling of RG in municipalities near the concrete tile plants. This paper investigates the use RG as replacement of 7.5% and 15% silica aggregate in concrete roof tiles. Three grading of RG were studied, i.e. particles retained between 4.76 – 1.68 mm, 1.68 – 0.84 mm and 0 84 – 0.30 mm sieves. Metakaolin (MK) has been chosen to replace 7.5% and 15% wt. cement and potentially suppress ASR. The physical properties assessed were dry bulk density, compressive strength and modulus of elasticity; the engineering properties determined were apparent porosity and oxygen permeability. Results showed that the use of 7.5% RG in combination with 7.5% MK provided equivalent performance to reference semi-dry pre-cast concrete and, therefore, permit a new route of disposal for the RG. Copyright © 2011 IAHS.
