Multi-scale improved damping of high-volume fly ash cementitious composite: Combined effects of polyvinyl alcohol fiber and graphene oxide

摘要

Implementation of high-volume fly ash (HVFA) in cementitious composites helps reduce matrix toughness and thus improve damping property. In this study, graphene oxide (GO) (0.05%, 0.10%, and 0.20%) and polyvinyl alcohol (PVA) fiber (1% and 2%) were added to enhance the damping ability of the HVFA system. Combined effects of GO and PVA fiber on static/dynamic mechanical properties and interfacial microstructure were studied. The strength tests indicate that incorporating 0.10% GO and 2% PVA fiber can effectively improve 28-d flexural and compressive strengths of the HVFA system by 244.1% and 46.4% respectively, compared with those of the control group (without GO and PVA fiber addition). In addition, a combination of 2% PVA fiber with excessive 0.20% GO content improved the loss factor and energy dissipation ratio by 55.2% and 69.4%, respectively. Microstructural analysis shows that there were several fiber-matrix interfaces, which can dissipate energy under dynamic loading, that were supplemented by the added GO acting as a filler and nucleation site to enhance coulomb friction. Thus, the proposed strategy develops a novel composite with superior damping ability by synergistically using HVFA, GO, and PVA fiber. (C) 2020 Elsevier Ltd. All rights reserved.