Effect of multiwalled carbon nanotube in cement composite on mechanical strength and freeze-thaw susceptibility

This paper presented the effect of a multiwalled carbon nanotube (CNT) in a cement paste composite mixture. In this study, various cement-CNTcomposites and an equivalent control mix were prepared by replacing 0.5, 0.75, and 1.0 % of cement with CNTs (by weight of cement). Different tests, such as compressive and flexural strength as well as freezing and thawing resistance of the CNT composites, were conducted. Cylindrical specimens of approximately 15.8 by 31.6mm and beam specimens of approximately 20 by 20 by 80mmwere prepared for compressive and flexural strength tests. The specimens were tested at 7, 28, 60, 90, and 180 days of curing. Results showed that compressive and flexural strength increased with respect to control mix when 0.5 % CNTwas added to the cement. The performance of cement-CNTcomposites against freezing and thawing action was inferior to that of the control mix. The relative dynamic modulus (RDM) of cement-CNTcomposites decreased more rapidly than that of the control mix. In addition, cement-CNTcomposites exhibited a faster rate of mass loss and length expansion than the control mix