FINE AGGREGATE

The increasing demand for sustainable and environmentally friendly construction materials has prompted the exploration of alternative waste materials for use in concrete production. This study investigates the partial replacement of fine aggregate with periwinkle shell in concrete as a means of reducing construction costs, conserving natural resources, and promoting waste utilization. The research evaluates the effects of incorporating varying percentages of processed periwinkle shell as a substitute for fine aggregate on the properties of concrete.
Concrete mixes were prepared with different replacement levels of fine aggregate using periwinkle shell, while a control mix containing conventional materials was also produced. Standard laboratory tests were conducted to determine the workability, density, compressive strength, and durability characteristics of the concrete specimens. The results indicate that the inclusion of periwinkle shell influences the fresh and hardened properties of concrete. Workability generally decreased with increasing replacement levels, while compressive strength showed acceptable performance at lower replacement percentages. The density of the concrete also reduced, suggesting the potential for producing lightweight concrete.
The findings reveal that periwinkle shell can be effectively utilized as a partial replacement for fine aggregate in concrete production without significantly compromising structural performance when used within optimal replacement limits. The study concludes that the use of periwinkle shell contributes to sustainable construction practices by reducing environmental waste and the dependence on natural sand resources. It is recommended that partial replacement levels within the optimum range be adopted for non-critical and selected structural applications

This study aims to investigate the potential of using pulverized glass as a partial substitute for fine aggregate in concrete, focusing on how it affects the mechanical properties of the resulting composite. By exploring various replacement levels of pulverized glass, the project identified an optimal balance that enhances both the sustainability and performance of concrete. An experimental work was performed to study the slump, unit weight, compressive strength, dry density and water absorption of concrete partially substituted with pulverized glass. A concrete mix with a target mean strength of 20N/mm² was designed using a standard 1:2:4 mix ratio. Pulverized glass was used to partially replace the fine aggregate at replacement percentages of 0%, 5%, 10%, and 15% in accordance to relevant literature. The concrete was then cast into cubes and allowed to cure for 7, 14, and 28 days at room temperature in a laboratory. The results indicate that workability increases with higher pulverized glass content, with slump values rising from 30 mm for the control mix to 46 mm at 15% replacement. However, compressive strength generally decreased as the replacement percentage increased. The 5% replacement mix achieved the highest compressive strength among the modified mixes, with an average 28-day strength of 19.72 N/mm² compared to 20.68 N/mm² for the control mix. Nine concrete mixes were examined using discarded glass in place of 0%, 5%, and 15% of the weight of sand. The study concludes that, crushed glass can substitute up to 5% of fine aggregate in concrete, which helps lessen the effects of sand mining. This concrete can be regarded as eco-friendly since it uses less raw materials and has fewer negative environmental effects.