49 / 2022-03-30 00:04:12

Effect of Anodic Polarization on Mechanical Behavior of Carbon Fabric Reinforced PE/CF Hybrid Fiber Cementitious Composites

Cathodic protection,HyFRCC,PE fiber,Mechanical behavior,Carbon fiber

An integration of impressed current cathodic protection (ICCP) and structural strengthening (SS) as ICCP - SS technology has emerged which aims at improving the structural longevity of corroded reinforced concrete structures. The carbon fabric reinforced cementitious matrix (C-FRCM) has been adopted as a dual-functional material for transferring protection current and enhancing loading capacity simultaneously. However, the brittle property of cementitious matrix and poor bond performance between carbon fabric and matrix limited the efficiency of carbon fabric. Moreover, the degradation of C-FRCM resulted by anodic polarization in ICCP process further constricted the efficiency of carbon fabric. In the present paper, a hybrid fiber reinforced cementitious composites (HyFRCC) was prepared as the matrix. The mechanical behavior and degradation of carbon fabric mesh reinforced HyFRCC (CFM-HyFRCC) was studied and discussed.

HyFRCC was composed of polyethylene (PE) fiber and carbon fiber as well as mortar matrix. The volume fraction and length of carbon fiber were considered in the preparation of HyFRCC. The mechanical behavior of CFM-HyFRCC was studied by uniaxial tensile tests and digital image correlation (DIC) measuring. In addition, an anodic polarization test was performed at different anodic current densities on CFM-HyFRCC. The degradation of mechanical behavior of CFM-HyFRCC was evaluated.

The results show that the mechanical strength of CFM can be released and activated completely in the case of the synergistic effect of CFM reinforcement and HyFRCC matrix. An excellent tensile performance of CFM-HyFRCC was obtained by using HyFRCC at hybridizing 1.5 vol% PE fiber and 1.0 vol% carbon fiber with 3 mm length. A trilinear tensile constitutive model of CFM-HyFRCC was proposed based on the cracking strength and debonding strength as well as ultimate strength. The tensile strength of CFM-HyFRCC was decreased as increasing charge densities, resulting in the reduction of the utilization efficiency of CFM. However, the deterioration of mechanical behavior and the feeding voltage of ICCP system were decelerated by hybridizing carbon fiber in the single-doped PE fiber reinforced cementitious matrix. The tensile constitutive model of CFM-HyFRCC was also transformed from trilinear to bilinear relation after anodic polarization.