Performance variation of graphene nanoplatelets reinforced concrete concerning dispersion time

Abstract

Graphene Nanoplatelets (GNP) are one of the most recent, unique and advanced derivative of carbon nanostructures. To achieve uniform dispersion of GNP in cement composite and at the same time to convert GNP into energy-efficient material, research is carried out. In this study, the dispersion ability of Graphene Nanoplatelets is evaluated through the performance of GNP-reinforced concrete. The graphene is dispersed through shear exfoliation using a homogenizer at a speed of 4000 revolutions per minute (rpm) with a polycarboxylate-based surfactant. Accordingly, two types of graphene are prepared depending on the time, exfoliated for one hour (60 m-G) and exfoliated for half an hour (30 m-G). The particle size distribution of both graphene dispersion is evaluated through an optical microscopic analyzer. The dispersed GNP are incorporated into concrete at 0.25 wt% by high-speed mixing; the mechanical and durability properties of graphene-reinforced concrete are evaluated. The experimental results indicated that the compressive and flexural strength of concrete increased by 40.17% and 54.54% by adding one hour shear exfoliated GNP. On the other hand, water and chloride permeability of 30 m-G concrete is reduced by 40.53% and 23.04%, respectively, indicating a reduction in permeability. The mechanical properties of 60 m-G incorporated concrete are better than 30 m-G concrete, but the durability properties are disparate due to the particle size distribution of Graphene Nanoplatelets.