Properties of Metakaolin-Based Geopolymer Mortar Incorporated with Multi-Walled Carbon Nanotubes

The use of alternative materials, predominantly with high levels of supplementary cementitious materials and geopolymer composites for the development of the construction industry is proposed. Metakaolin-based geopolymer mortar along with corn cob ash (CCA) and multi-walled carbon nanotubes (MWCNTs) were characterized and tested. The properties of geopolymer mortar were studied by varying the concentrations of multi-walled carbon nanotubes (0%; 0.25%; 0.5%; 0.75% and 1%) along with the replacement levels of metakaolin with corn cob ash (0–10% about 2.5% increment). From the scanning electron microscope analysis, it was depicted that the MWCNTs were distributed uniformly within the geopolymer matrix at 0.50%, while at 1% these were poorly distributed and agglomerated within the matrix. Experimental investigation revealed that there was a significant increase in compressive strength of metakaolin-based geopolymer mortar when CCA and MWCNTs were combined at 5% of CCA and 0.5% of MWCNTs, but beyond this combination, there was a reduction in strength.