Carbon nanotube-cement composites : a retrospect

Although ordinary Portland cement (OPC) is widely used in the construction industry, its weak tensile strength, to some extent, limits its application. A carbon nanotube (CNT), on the other hand, has outstanding mechanical properties with a tensile strength of 63 GPa and Young's modulus of 1 TPa, making it a candidate as nano-scale reinforcements in OPC. Past research studies have reported improved mechanical and electrical properties of carbon nanotube-ordinary Portland cement (CNT-OPC) composites, which show future promise in practical civil engineering applications. In this study, recent research studies in developing CNT-OPC composites are comprehensively reviewed. Highlighted herein are the considerable efforts been made in the study of fabrication, hydration, porosity and transport properties of the CNT-OPC composites. There are, however, future investigations needed to provide a better understanding in the areas of uniform dispersion of CNTs within the OPC paste, durability, impact, fatigue properties and the theoretical modelling of CNT-OPC interaction.