Effect of Carbon Nanotubes Treated Aggregates on Compressive Strength of Concrete

Abstract

This paper presents the results of a series of compression tests on concrete with carbon nanotubes (CNTs) treated aggregates and untreated aggregates at different curing ages. The compressive tests were conducted after 3, 7 and 28 days curing to capture the effect of CNTs treated aggregates on the stress-strain behavior of concrete and strength development. The results show a slight reduction in terms of compressive strength at different curing ages when CNTs treated aggregates are incoporated in concrete. Apart from the reduction in compressive strength, a significant improvement in ductility can be found. The reduction is related to the adhesion between aggregates and CNTs that becomes the weak link in concrete although the interfacial transition zone (ITZ) can be enhanced by the CNTs, which results in a reduction of compressive strength. The sliding among aggregates, CNTs and cement matrix provides the tolerance towards the deformation for the entire material system, leading to a enhanced ductility.