Carbon nanotubes' amount and type: Crucial parameters in mechanical performance enhancement on cement paste nanocomposites

Abstract

Single-wall (SWCNTs) and multi-wall (MWCNTs) carbon nanotubes' affection on mechanical properties of cement-based nanocomposites is investigated in the present research. Three different amounts of CNTs, namely 0.05 %, 0.1 %, and 0.5 wt.% by weigth of cement were incorporated in nanomodified cementitious specimens. Flexural and compressive strength were determined for both types. The results reveal that MWCNT nanocomposites exhibit an improved mechanical performance for both flexure and compression as a function of the concentration up to 0.1 wt.% of the cement in contrast to SWCNT modified cementitious composites where the CNT addition leads either to a slight increase or a decrease. Results clearly reveal that the different type of reinforcement at the nanoscale beneficially alters the structure of the cement paste and enables the material to perform multiple structural functions. This investigation is expected to contribute significantly to create a cement based materials with improved mechanical performance.