Effects of multi-walled carbon nanotubes on strength and interfacial transition zone of concrete

Multi-walled carbon nanotubes (MWCNTs) were used to try and eliminate the aggregate interfacial transition zone. Different concrete mixes were used in fixed proportions along with varying concentrations of CNTs. The CNTs were applied in different concentrations, namely, 0.05 wt%, 0.1 wt% and 0.2 wt%, per dry weight. CNTs were dispersed using sonication. Concrete specimens were tested for compressive, flexural and split-tensile strengths. For each test, thirteen mix designs were investigated which included untreated aggregates and CNTs, and treated aggregates and CNTs. The results were compared with the results of the control concrete. The results showed that the use of CNTs improves the compressive, flexural and split-tensile strengths. It was concluded that CNTs minimize the ITZ