Dispersion effectiveness of carbon nanotubes in smart cementitious materials Available to Purchase

Applying carbon nanotubes (CNTs) as an additive in cement has high potential to achieve smart cementitious materials. However, the small fraction of CNTs in the cementitious materials may not be sufficient to provide strong piezo-resistive signals for monitoring the materials’ performance accurately in the field. In this study, a theoretical transfer function is developed to analyse the dispersing effectiveness of CNTs in order to search for a stronger piezo-resistance effect in smart cementitious materials. The theoretical transfer function model introduces a dispersing effectiveness coefficient into the intrinsic resistance and the inter-tube resistances of CNTs in the cementitious mix matrix. To validate the developed model, two different dispersing methods, including direct mixing and surfactant methods, were investigated through laboratory experiments. The experimental data showed that the developed transfer function can distinguish the dispersing effectiveness well for the two different methods investigated. This model can be used to guide evaluation regarding the quality control of CNT-based smart cementitious materials and investigation of the effectiveness of new developments of dispersion methods in the future.