Experimental Analysis of Multiwalled CNT-incorporated Self-compacting Mortar (SCM)

Abstract

Abstract The placement of reinforcement and mortar in narrow sections of a framework is a significant challenge in the construction industry. Self-compacting mortar (SCM), despite its ability to flow under its own weight, exhibits reduced durability, flexure, and compressive strength due to its porous and brittle nature. As the demands for high-rise structures, coastal tunnels, pass bridges, and sustainability increase, the development of high-performance SCM is crucial. Carbon nanotubes (CNTs) are indeed the strongest known materials to date and could be utilized to enhance the functionality and strength of traditional SCM. Therefore, it is imperative to investigate the effect of multiwalled carbon nanotubes (MWCNTs) on the fundamental properties of SCM. In this study, the fresh and mechanical properties of conventional SCM were evaluated with the addition of MWCNTs. Specifically, 0.05%, 0.1%, 0.15%, and 0.5% MWCNTs by mass of cement were incorporated into SCM. The results indicate that the incorporation of MWCNTs has a retarding effect on the workability of fresh SCMs, yet the flow spread values still comply with the EFNARC standard for SCMs without segregation or bleeding. Additionally, the optimal content of MWCNTs was 0.1%, which led to a significant enhancement in flexural and compressive strength of SCMs at 28 days, 54.6% and 61.2%, respectively, compared to the control specimen of SCMs, a breakthrough that could have important implications in the construction industry.