Development of High Strength and High Ductility Cementitious Composites Incorporating CNF-Coated Polyethylene Fibers

Abstract

In this study, high strength and high ductility cementitious composites were developed by incorporating carbon nanofibers (CNFs) coated polyethylene (PE) fibers. The CNFs were coated on the PE fiber surface through hydrophobic interaction to strengthen the interface transition zone (ITZ) between PE fibers and cement-based matrix. The resulting composite has a compressive strength over 150 MPa and a tensile strain capacity exceeding 2%. Results showed that CNF coating on PE fiber reduces cracking spacing and enhances the tensile strength and tensile strain capacity of composites by 15% and 20% respectively. It is plausible that CNF on PE fiber may fill nano-pores and bridge nano-cracks in the fiber/matrix ITZ, resulting in denser microstructure and higher crack resistance against fiber pullout. The increased interface frictional bond strength leads to higher tensile strength and strain capacity.