Experimental Investigation Of Lightweight Concrete Using Coconut Shells And Crushed Glass As Partial Aggregates

The growing demand for natural aggregates in concrete production has led to concerns regarding the environmental impact and depletion of resources. This research investigates the mechanical properties of concrete modified with coconut shells and crushed glass as partial substitutes for conventional aggregates, aiming to promote sustainable construction practices. Various replacement levels (0%, 6%, 12%, 18%, 24%, and 30% by weight) were tested in M30 concrete mixes using Ordinary Portland Cement (OPC) and natural aggregates. The findings reveal significant alterations in concrete properties due to these substitutions. While coconut shells led to a modest reduction in early strength and workability-with a maximum impact value increase to 32.53%— they provided adequate strength for applications with lower surface wear, peaking at a crushing value of 40.03%. Conversely, crushed glass demonstrated superior mechanical performance, achieving an impact value of 35.16% and contributing positively to both early compressive strength (25.11 N/mm²) and long-term strength (37.73 N/mm²). Additionally, the inclusion of glass resulted in better abrasion resistance, with maximum values reaching 42.53%, compared to 41.20% for coconut shells