Abstract

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The reuse of waste glass in concrete production is an attractive option for achieving waste reduction and preserving natural resources from further depletion, thereby protecting the environment and promoting sustainability. This present study examined the variation in the strength properties of concrete using waste glass aggregate (WGA) as a partial replacement for different coarse aggregate gradings. Three-quarter-inch (20 mm) and one-inch (25 mm) coarse aggregates were partially replaced with WGA of the respective sizes in different percentages: 0 %, 10 %, 20 % and 30 %. Physical properties such as specific gravity, bulk density, slump, and workability of fresh concrete and strength properties such as compressive strength and tensile strength of hardened concrete of grade M25, mix ratio 1:1:2 were tested after 7, 14, 28, 56 and 90 days. The results of the physical properties revealed that the WGA exhibited a lower specific gravity value of 2.70, bulk density of 1364 kg/m3, and moisture content of 0 % as compared to granite, with a specific gravity value of 2.74, bulk density of 1660 kg/m3, and moisture content of 0.01 %. The compressive strength results of both 20 mm and 25 mm WGA increase as the curing age of the concrete increases progressively from 7 days up to 90 days. At 7 and 90 days the compressive strength results of 20 mm aggregate of the control mix concrete were 30.05 N/mm2 and 42.60 N/mm2 respectively while that of 20 mm 30 % WGA partial replacement were 32.14 N/mm2 and 45.70 N/mm2 respectively, and for 25 mm aggregate control mix concrete were 29.74 N/mm2 and 49.80 N/mm2 respectively, while that of 25 mm, 30 % WGA partial replacement were 28.71 N/mm2 and 45.50 N/mm2 respectively. The tensile strength for all the ages reached the optimum value at 10 % partial replacement WGA for both 20 mm and 25 mm. At 28 days, the tensile strength result of 20 mm aggregate of the control mix concrete was 2.86 N/mm2, while 20 mm 10 % WGA replacement was 2.90 N/mm2, and for 25 mm aggregate control mix concrete, the tensile strength result was 3.11 N/mm2, while that of 25 mm WGA was 2.55 N/mm2. The results of the strength properties showed that the concrete grade M25 adopted was suitable for the WGA partial replacement, as the compressive strength results for all ages did not fall below 25 N/mm2.

Keywords: Waste-glass, Strength properties, Partial replacement, Coarse aggregates, Grading.