The effect of graphene oxide coating on the performance of SHCC

Abstract

This study develops a novel graphene oxide (GO) coated polyethylene (PE) fiber which can be used to fabricate Strain-Hardening Cementitious Composites (SHCC). PE fiber can be covered by the GO due to the different thermal expansion behavior. This layer of GO coating would increase the fiber surface wettability and roughness, and also chemically improves the functionality and reactivity of PE fiber. Therefore, the interfacial bond between fiber and matrix can be improved. Since the bond between pristine PE fiber and cementitious matrix is usually too weak, theoretically the tensile performance of PE-SHCC after GO coating on the PE fiber (GO/PE-SHCC) can be improved if the fiber/matrix bond is strengthened. From the experimental results, it indicates that the tensile strain capacity of SHCC using 2 vol.% GO/PE fiber can be improved by 96.62 % (from 3.5% to 6.4%), compared to pristine PE-SHCC. The enhanced interfacial bond between fiber and matrix after GO coating is also confirmed by conducting the single fiber pullout test, which indicates that the peak pullout load can be improved by 45.16% (from 0.62N to 0.90N). These single fiber pullout results are further input into a micromechanical based model to generate the single crack fiber bridging law, and the potential of multiple cracking and robustness of strainhardening behavior is then evaluated by the model, which predicts GO/PE-SHCC should have better performance than pristine PE-SHCC. In conclusion, the research outcomes provide an effective strategy to strengthen the interfacial bond between PE fiber and matrix through GO coating, leading to the development of a novel SHCC with the strain up to 6 %.