Experimental Investigation on the Effect of Graphene Oxide on Mechanical Properties of M20, M30 and M40 Grade Concrete

Abstract

Concrete is the most widely used construction material due to its high compressive strength, durability, availability and economy. However, conventional concrete contains capillary pores, micro-cracks and weak interfacial transition zones, which reduce its mechanical and durability performance. In recent years, graphene oxide has been studied as an effective nano-material for improving cement-based composites because of its high specific surface area, two-dimensional sheet structure and oxygen-containing functional groups. The present study investigates the effect of graphene oxide on the fresh, mechanical and durability properties of M20, M30 and M40 grade concrete. Graphene oxide was added in different dosages of 0%, 0.025%, 0.05%, 0.075% and 0.1% by weight of cement. The workability of fresh concrete was evaluated using slump and compaction factor tests. Hardened concrete properties were studied using compressive strength, split tensile strength and flexural strength tests. In addition, durability-related performance was assessed through water absorption, water permeability and acid attack resistance tests. The results showed that the addition of graphene oxide improved the mechanical strength of concrete compared with the control mix. The maximum compressive strength for M20, M30 and M40 grade concrete was observed at 0.05% graphene oxide dosage. However, workability decreased with increasing graphene oxide content due to its high surface area and water demand. The durability performance also improved at optimum dosage due to pore refinement and densification of the cement matrix. The study confirms that graphene oxide can be used as a promising nano-additive in concrete, but proper dispersion, dosage control and cost feasibility must be considered for practical construction applications.