纳米SiO2和混杂纤维增强环氧树脂水泥基修复材料抗压强度研究OA

[Objective]This study aims to investigate the variation in compressive strength of nano-SiO2 and hybrid fiber-re-inforced epoxy resin cementitious repair materials(NF-ECRM),and to reveal the influence mechanism of epoxy resin emul-sion,nano-SiO2 and polyvinyl alcohol(PVA)-steel hybrid fiber on the compressive strength.[Methods]Cube compressive strength tests were conducted to analyze the effects of the contents of epoxy resin,nano-SiO2,and PVA-steel hybrid fibers on the compressive strength of NF-ECRM.Scanning electron microscope tests were performed to reveal the strengthening mecha-nism of the compressive strength of NF-ECRM.[Results]With the increase in epoxy resin content,the compressive strength of epoxy resin cementitious repair materials(ECRM)and NF-ECRM both showed a decreasing trend.Meanwhile,the com-pressive strength of NF-ECRM gradually increased with the increase in nano-SiO2 content,while it first increased and then de-creased with the increase in PVA fiber content,reaching the peak when the PVA fiber content was 0.9%.[Conclusion]Ep-oxy resin can effectively relieve internal stress in the cementitious repair material matrix and inhibit the formation and expan-sion of micro-cracks.Nano-SiO2 can reduce pore defects of the cementitious repair material matrix and improve the compact-ness of the interfacial transition zone.Moreover,PVA-steel hybrid fiber can significantly enhance the integrity and crack re-sistance of the cementitious repair material matrix.