Impact of graphite nano/microplatelets on the mechanical and durability performance of concrete by incorporating mill scale waste

Abstract Graphite nano/microplatelets (GNMPs), which are part of the tetral family (group 14 elements), exhibit significant potential to enhance the mechanical and durability attributes of concrete due to their multi-functional filler properties. Mill scale waste (MSW), is a residual byproduct of the steel industry that can be used in concrete as a replacement for sand, thereby avoiding pollution and depletion of natural resources of aggregates. Although (GNMPs) enhance some of the mechanical properties of concrete and (MSW) has also impact on concrete properties, no information is available, particularly on the influence of both (GNMPs) and (MSW) in concrete. Therefore, in this research, an innovative concrete was prepared by using varying amounts of GNMPs (0%, 0.1%, 0.2%, 0.3%, and 0.4% by weight of cement) and replacement of sand with MSW (0%, 25%, 50%, and 75% by weight of sand). These concrete mixes were tested for properties such as workability, density, compressive strength, splitting tensile strength, flexural strength, and durability. Tests including bulk water sorption and acid attack resistance were conducted on the concrete specimens. The microstructural analysis of concrete with GNMPs and MSW was carried out through scanning electron microscopy (SEM). Results indicated that the addition of (GNMPs) and (MSW) increased concrete density and decreased its slump value when compared to the control mix. The compressive, splitting, tensile, and flexural strengths of the mixes were increased at specified proportions of up to 0.3% GNMPs and 50% MSW content. It also resulted in a reduction of water sorptivity, mass, and compressive strength loss against acid attack. The results demonstrated that MSW and GNMPs can be utilized in concrete for sustainable construction practices.