Intrinsic effect of hybrid fibres 3D network on the electrochemical characteristics of Ultra-High Performance Fibre Reinforced Composites (UHPFRC)

This study addresses the intrinsic effect of hybrid fibres 3D network on the electrochemical characteristics of Ultra-High Performance Fibre Reinforced Composites (UHPFRC), including experimental investigations and mechanism analysis. Firstly, the matrix of the UHPFRC is fabricated based on the modified Andreasen & Andersen model. Then, three types of fibres (long steel fibre (LSF), short steel fibre (SSF) and polyvinyl alcohol fibre (PVA)) are further incorporated into the developed UHPFRC to generate different hybrid fibres 3D network. After that, the mechanical properties, chloride permeability and electrochemical properties of the designed UHPFRC with hybrid fibres are analyzed. The obtained results exhibit that with an increase of PVA content, the steel fibre network can be significantly disturbed, and the capacity of designed UHPFRC almost decrease linearly. In contrast, the added SSF cause that the capacity of UHPFRC with hybrid will decrease firstly and then increase. This implies that there is a balance point for the fibres hybridization design, with which the electrochemical corrosion resistance and mechanical properties of UHPFRC can be well optimized. At last, X-ray CT is further employed to quantitatively understand the fibres 3D network structure of the developed UHPFRC.