Comparative analysis of the synergistic effects of hybrid nanomaterial reinforcement in cementitious Composites: A perspective for pore refinement and thermal resistance

Abstract

This study aimed to reveal the synergistic effects of graphene oxide (GO)/nanosilica (NS)/functionalized carbon nanotube (FCNT) hybrid nanomaterials on the thermal resistance and pore refinement of cementitious composites. The dispersion states and sizes of the nanomaterials in distilled water and Ca2+-rich solutions were assessed. In addition, the pore characteristics and thermal resistance of the nanomaterial-incorporated cementitious composites were analyzed. In the GO/NS/FCNT hybrid solution, a reinforcing effect of FCNT on the GO plate resulted in high resistance to wrinkling and agglomeration of GO; therefore, the stretched GO plate structure was advantageous for long-term dispersion maintenance, and well-dispersed NS enabled a more active pozzolanic reaction in cement paste. As a result, the triple-hybrid GO/NS/FCNT-reinforced cementitious composites demonstrated improved thermal resistance owing to their high residual strength after heating as well as homogenized pore structures with less elongated pore shapes and lower porosity than control specimens without nanomaterials.