Synthesis of Ultra-High Performance Cementitious Composite incorporating Carbon Nanotubes

Abstract

Ultra High-Performance Concrete (UHPC) is a type of special concrete developed to meet the demand for niche applications in the industry, where this type of concrete comes with enhanced durability and superior mechanical characteristics in comparison to conventional normal- and high-strength concrete. However, UHPC has its drawbacks in terms of lower tensile strength ratio and brittleness. Nanomaterials such as carbon nanotubes (CNT) with their superior mechanical properties are potential candidates to act as nano-reinforcement in Ultra High-Performance Cementitious Composite (UHPCC) matrix, to create a more denser and ductile UHPCC system. However, prior to arriving at the “desired” UHPCC mix design, attention has to be paid to the process of dispersing the CNT into the fresh composite mix since the dispersion of CNT in cement-based material is a challenge due to their agglomerating behaviour. This paper presents on the synthesis of UHPCC mix design which optimizes on its packing density of its constituent materials. The influence of different dispersion methods of CNT on the mechanical strength and microstructure of UHPCC are also reported. It was found that samples reinforced with CNT exhibit higher compressive and tensile strengths and denser microstructure compared to control samples without CNT.