Enhancing microstructural integrity and mechanical strength of mortar containing incinerated ash using carbon nanotube, graphene nanoplatelet and nano silica reinforcements

Abstract

Abstract

Incineration ash contains metallic aluminium that can react with cement alkalis, producing hydrogen gas, which can affect the strength of cementitious materials. In this study, we aimed to improve the technical properties of incinerated ash-based mortar using three different nanomaterials: carbon nanotubes, graphene nanoplatelets, and nano-silica. These nanomaterials were incorporated at concentrations of 0.025 wt%, 0.05 wt%, 0.1 wt%, 0.25 wt%, 0.5 wt%, and 1 wt% of the cement mass, respectively. Comprehensive analysis indicates that the type of nanomaterials and their doses play a significant role in early age hydration, shortening the induction period and promoting the formation of C-S-H. Study results show evidence up to a 45 % enhancement in compressive strength. Sustainability assessment reveals that a dose of 0.025 % graphene nanoplatelets is the most sustainable from an environmental perspective, with approximately a 25 % improvement in compressive strength of incinerated ash mortar. Findings of the study will contribute to the understanding of nanomaterial-reinforced cementitious systems incorporating incinerated ash and offer valuable guidance for improving the performance of incinerated ash-based cementitious materials in construction applications.