Influence of multi-scale three-dimensional pore characteristics on the mechanical properties of graphene oxide and carbon nanotube incorporated cement paste

The correlation between the three-dimensional pore characteristics and mechanical properties of graphene oxide (GO)-and carbon nanotube (CNT)-incorporated cement pastes were investigated. The nano and micro-scale pore characteristics were evaluated by analyzing pore shapes and spatial distribution properties using a radial distribution function (RDF). As a result of the nucleation sites effect, blade-like and plate-like pores were primarily formed in the GO-incorporated samples and rod-like pores in the CNT-incorporated samples, as compared to the plain samples without nanomaterials. In addition, the pore scattering, instead of the pore clustering property, was improved in the nanomaterial-incorporated samples. Notably, results obtained from X-ray nanoimaging and micro-CT analyses revealed a strong positive linear correlation between the strengths (compressive and splitting tensile strengths) of the composites and the degree of pore scattering.