模拟海水-海砂混凝土环境下连续玻璃纤维增强聚丙烯复合材料杆层间剪切性能的演化

Interlaminar shear behavior of glass-fibre reinforced polypropylene rod under seawater and sea sand concrete simulation environment

连续玻璃纤维增强聚丙烯(GFRPP)复合材料杆集成了热塑性树脂可多次成型、环境友好、可回收利用和玻璃纤维高应变、低成本等优点,在混凝土结构领域,GFRPP复合材料有望替代钢筋和热固性纤维增强聚合物(FRP)筋成为新型热塑性复合材料。本文采用加速实验研究了模拟海水-海砂混凝土环境下GFRPP杆的水吸收及层间剪切性能长期演化规律与退化机制。研究结果表明:GFRPP杆吸水行为符合Fick定律,21℃、40℃和60℃浸泡温度下GFRPP杆的饱和吸水率分别为0.63%、0.78%和0.81%;经120天21℃、40℃和60℃模拟海水-海砂混凝土孔溶液浸泡后,GFRPP杆层间剪切强度保留率分别为80.5%、72.8%和66.5%。最后,结合SEM和FTIR表征技术,揭示模拟海水-海砂混凝土孔溶液浸泡下GFRPP杆性能退化机制。

Glass-fibre reinforced polypropylene(GFRPP)composite rod integrate the advantages of thermoplastic resin multi-molding,environmental friendliness,recyclability,and high strain and low cost of glass fiber.In the field of concrete structures,GFRPP rods are expected to replace steel bars and thermoset fibre reinforced polyer(FRP)bars as a new composite material.In this paper,accelerated experiments were used to study the long-term evolution of water absorption,interlaminar shear properties and degenerative mechanism of GFRPP rod under simulated seawater and sea sand concrete environment.The results show that the water absorption behavior of GFRPP rod conforms to Fick's law,and the saturation water absorption rates of GFRPP rods at immersion temperatures of 21°C,40°C and 60°C are 0.63%,0.78%and 0.81%,respectively.After 120 days of immersion in 21°C,40°C and 60°C simulated seawater sea sand concrete pore solutions,the shear strength retention rates between GFRPP rods are 80.5%,72.8%and 66.5%.Finally,the performance degradation mechanism of GFRPP rods under simulated seawatersea sand concrete pore solution immersion was revealed by combining SEM and FTIR characterization techniques.