Using Recycled Glass as a Partial Replacement of Fine Aggregate to Produce Green Concrete

Twenty concrete mixtures (300 concrete cylinders) were cast to investigate the properties of green concrete incorporating recycled glass. The mixtures had water-to-cement ratio of 0.46, recycled glass percentage partial replacements of natural sand of 0%, 15%, 30%, or 50% by weight, and different proportional weight ratios of coarse aggregates of 1.0%, 1.5%, 2.0%, 2.5%, or 3.0%. Concrete cylinders were cured at different curing periods of 7 days, 28 days, or 52 days. The mechanical strength (compressive, splitting, and ultrasonic) tests were utilized to evaluate concrete mixtures. The results found that extending curing period for majority of concrete mixtures from 7 days to 28 days showed a statically significant increase in the compressive strength. Whereas, extending curing period beyond 28 days up to 52 days did not have a clear impact on the compressive strength. In case of using recycled glass in a concrete mixture, the proportional weight ratio of coarse aggregate should be reduced to maintain the value of compressive strength. Up to 50% recycled glass can used to produce green concrete with high compressive strength.