Experimental Investigation on Concrete with Partial Replacement of Aggregates by Marble Pieces and Plastic Granules

Abstract: Concrete is the most widely used construction material because of its strength, durability, versatility, and availability. At the same time, the construction sector consumes large quantities of natural aggregates and generates or receives large quantities of waste materials. Marble processing produces solid waste in the form of pieces and fragments, while plastic waste creates long-term environmental concerns because of its persistence and difficult disposal. This study investigates the possibility of using these two waste materials in concrete as partial replacements for conventional aggregates.

The experimental study considers M30 grade concrete. Marble pieces are used as a partial replacement for natural coarse aggregate, while plastic granules are used as a partial replacement for natural fine aggregate. The project methodology includes material testing, concrete mix proportioning, casting and curing of specimens, and strength evaluation after 7, 14, and 28 days. The synopsis specifies compressive strength, split tensile strength, and flexural strength as strength characteristics to be evaluated.

The reported results show that concrete strength generally increases with curing age. Among the replacement levels considered, the mixes containing 30% marble pieces and 7% plastic granules produced the highest reported strength performance. The synopsis concludes that higher replacement levels of 40% marble pieces and 9% plastic granules resulted in a reduction in strength, attributed to weaker bonding and increased voids.

The study therefore identifies 30% marble pieces with 7% plastic granules as the optimum combination among the investigated mixes. The findings indicate that appropriately proportioned marble and plastic waste can be incorporated into concrete while reducing dependence on natural aggregates and supporting more sustainable construction practices.

Keywords: M30 concrete, marble waste, plastic granules, coarse aggregate, fine aggregate, compressive strength, split tensile strength, sustainable concrete.