“Performance Evaluation of Concrete with Partial Replacement of Fine Aggregate by Glass Cullet and Cement by GGBS”

Concrete is the most widely used construction material; however, the excessive consumption of natural resources and the high carbon footprint associated with cement production have raised serious environmental concerns.The utilization of industrial and construction waste materials in concrete offers a sustainable alternative by reducing environmental impact while improving material performance.This experimental study investigates the effect of using glass cullet aggregate (GCA) as a partial replacement of natural aggregate along with ground granulated blast furnace slag (GGBS) as a partial replacement of cement in concrete.A series of concrete mixes were prepared with varying percentages of glass cullet aggregate and cement replacement, while a control mix was designed using conventional materials.Standard concrete specimens were cast and tested in accordance with Indian Standard codes (IS 456, IS 516, and IS 5816).The mechanical properties evaluated include compressive strength, split tensile strength, and flexural strength at 28 days of curing.The experimental results indicate that the strength characteristics of concrete improve with an increase in replacement levels up to an optimum proportion.The mix CG-G15-C30 exhibited the highest compressive, split tensile, and flexural strengths compared to the control concrete.Beyond this optimum level, a reduction in strength was observed, which may be attributed to weaker interfacial bonding and increased brittleness caused by higher glass content.The study concludes that the partial replacement of natural aggregates and cement with glass cullet aggregate and GGBS up to an optimum level is technically feasible, structurally effective, and environmentally sustainable.The findings support the potential use of waste glass and GGBS in concrete for sustainable construction practices, reducing the dependency on natural resources and minimizing waste disposal problems.