Suitability of Broken Bottles as Fine Aggregate for Production of Concrete
The use of broken bottles as partial replacement of river sand for production of concrete was investigated. The grading of the broken bottles and sand fell in zone II. The specific gravity of the bottles was 2.55 and that of sand was 2.65. Sand was replaced with the broken bottles in the proportions of 0%, 10%, 20%, 30%, 40%, and 50% by weight. The mix of 1:2:4 by weight and watercement ratio of 0.45 were used. Cubes of side 150mm were cast for each proportion, cured by complete immersion in water and tested for density and strength at the ages of 7, 14 and 28 days. The average compressive strength of the cubes was found to increase with curing age but decrease with increase in the proportion of broken bottles in the mix. The proportion of broken bottles to give a minimum strength of 20N/mm2 was 30% at 7 and 14 days, and 40% at 28days. The maximum mean compressive strength of 19.0N/mm2 was obtained at 28days when sand and broken bottles were used in equal proportions. Density did not appear to have a discernible trend. For structural concrete, the proportion of broken bottles should be limited to 30% for early strength concrete and 40% when early strength is not required. For non-structural concrete, proportion greater than 40% can be used.