The Effect of Graphene Oxide (GO) on Mechanical Properties of Fly Ash-Based Geopolymer-GO Composites

Abstract

This work deals with the effect of adding GO on the mechanical properties of fly ash-based geopolymer-GO composites. Compressive strength, water absorption, density, and flexural strength tests were carried out to investigate mechanical and physical properties of fly ash-based geopolymer-GO composites. The results showed that the addition of graphene oxide into fly ash-based geopolymer-GO composites up to threshold value (i.e., in this study, 1 gram or 1.1 wt.%) will decrease total porosity as well as a change in the total quantity of pores and their distribution due to densification of bulk matrix of the specimens. Consequently, it reduced water absorption, increased the density of the specimens, and subsequently increased mechanical properties (i.e., compressive strength and flexural strength). Conversely, the addition of graphene oxide into fly ash-based geopolymer-GO composites greater than above the threshold value will increase total porosity due to coarsening of bulk matrix of the specimens and subsequently increased water absorption and reduced density of the material. As a result, it decreased the mechanical properties (i.e., compressive strength and flexural strength) of fly ash-based geopolymer-GO composites. The present research demonstrates how graphene oxide can improve the mechanical properties of fly ash-based geopolymer-GO composites to a certain extent, which may match with industrial applications.