Effect of graphene oxide on the performance of foamed concrete and its action mechanism in cement

Abstract

The purpose of this study is to investigate the effect of graphene oxide (GO) on the performance of foamed concrete and its action mechanism in cement. The GO increased the nine-day and 15-day compressive and flexural strengths of foamed concrete compared to concrete without GO. When the GO dispersion (GOd) content was 0.75% (by the cement weight), the 15-day compressive strength of the foamed concrete increased by 36.36%. However, excess GO adversely affected the late-age compressive strength (30 days) because it was difficult to disperse uniformly in cement. The microstructure and hydration products of the foamed concrete were analysed using field-emission scanning electron microscopy combined (FEM) with X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy techniques (EDS). The GO could regulate the shape of hydration products, probably because GO exhibited a strong covalent bond between the oxygen-containing functional groups of GO and the cement hydration products, and the GO content and curing age influenced such regulations. The pore structure was examined using X-ray computed tomography, (X-CT) and the GO significantly influenced the pore structure of the foamed concrete. The findings of this study indicate that GO has potential as a nanometre-sized material to improve the strength of foamed concrete without affecting the dry density.