Effect of Carbon Nanotubes on Porosity and Mechanical Properties of Slag-Based Geopolymer

Abstract

In this study, the mechanical behavior and porosity of slag-based geopolymer composites containing multiwalled carbon nanotubes (MWCNTs) were investigated. Three parameters (water–binder ratio, carbon nanotube-to-dispersant ratio (CNT/dispersant ratio), and MWCNT content) were varied, and the compressive strength, flexural strength, and porosity of the composite matrix were determined. The results indicated that in comparison with the reference sample, the compressive and flexural strengths of the composites increased with the addition of 0.045wt% MWCNTs, owing to matrix porosity refinement. The mechanical properties of the composites reached their maximum values when the water–binder ratio was 0.4. Moreover, the dispersant influenced the mechanical properties of the composites. The optimal CNT–dispersant ratio was found to be 2.5:1, and the compressive and flexural strengths of the samples with this ratio increased by 48% and 55%, respectively.