Comparative study of mechanical strengths of cement pastes incorporating carbon nanomaterials with distinct surface chemistry and morphology

Abstract

This work investigated the use of two-dimensional graphene oxide (GO), one-dimensional oxidized carbon nanotube (OCNT) and graphene oxide nanoribbon (GONR), with a C/O ratio of 0.77, 2.79, 33.5, respectively, to reveal how the surface chemistry and dimensionality of carbon nanomaterials (CNMs) affect the mechanical strengths of cement pastes. The prepared GONR features the high oxidation degree similar to GO and high aspect ratio similar to OCNT, thus exhibiting both the characteristics of GO and OCNT in enhancing the mechanical strengths of cement pastes. With 0.01 wt% GONR admixed, the flexural and compressive strengths of cement pastes at 28 days were improved by 35.9% and 16.7%, respectively. Among the three CNMs, those with a higher oxidation degree promoted the formation of hydration products. Findings from this exploratory study shed light on the influence of surface chemistry and morphology of CNMs on cementitious composites.