EFFECT OF PARTIAL REPLACEMENT OF COARSE AGGREGATE BY CRUSHED BROKEN GLASS ON PROPERTIES OF CONCRETE

The importance of coarse aggregate in concrete cannot be overemphasized. Glass forms a major component of solid waste in many countries and can be recycled after use. Although, small proportion used by consumers has been recycled and reuse while about 70-80% is disposed in the landfill and this constitutes to environmental waste. This work investigated the suitability of glass as a partial replacement of conventional aggregate (crushed granite) in the production of concrete. The concrete was produced with coarse aggregates and were replaced by glass at 15%, 25%, 35% and 45% using a mix ratio of 1:2:4 with a water cement ratio of 0.6. Several tests were carried out ranging from aggregate to fresh and hardened concrete test. It was observed that the specific gravity of the glass was lower than that of granite was causing a reduction in the densities of the concrete. Workability of the concrete increased with the increase in the glass content which is indicated by the result of the slump test which gave 5mm, 10mm, 20mm, 40mm and 45mm for the 0%, 15%, 25%, 35% and 45% replacements. Reduction of the strength of the concrete increased at the increase in the percentage of the glass. The compressive strength of concrete with 100% granite at 28 days is 26N/mm2 , while that of concrete gave 25.04 N/mm2 strengths, 24.37N/mm2 , 22.22 N/mm2 and 21.55N/mm2 , for 15%, 25%, 35% and 45% replacement of granite with glass respectively. Concrete up to 20 N/mm2 strengths can be used for structural work. Therefore, it is recommended that aggregates can be replaced up to 45%, but 15% is not recommended