海洋环境下碳-玻璃纤维混杂筋吸湿行为和层间剪切性能研究

Effects of Marine Environment on Water Diffusion and Interlaminar Shear Strength of Carbon-Glass Hybrid-Fiber Reinforced Polymer Bars

采用薄碳纤维层外包裹玻璃纤维增强复合材料(GFRP)筋,制备碳-玻璃纤维混杂筋(HFRP筋),提升芯层GFRP筋长期力学性能,在海工结构中具有巨大的应用潜力。对水,强、弱碱,盐碱等溶液下GFRP、HFRP裸筋吸湿行为和层间剪切强度变化规律进行研究,同时与水、模拟海水溶液下砂浆包裹GFRP和HFRP筋的层间剪切强度进行对比分析。研究表明:强碱、盐碱溶液下,HFRP裸筋吸湿率小于GFRP裸筋,HFRP裸筋层间剪切强度保留率大于GFRP裸筋,碳纤维层延缓芯层GFRP筋劣化速率;水、弱碱溶液下,HFRP裸筋吸湿率大于GFRP裸筋,60℃下HFRP裸筋层间剪切强度保留率小于GFRP裸筋。水、模拟海水溶液下砂浆包裹GFRP和HFRP筋的破坏模式和层间剪切强度变化与水、弱碱溶液下GFRP和HFRP裸筋相似。基于Arrhenius理论,预测了强碱、盐碱溶液下GFRP和HFRP裸筋在4,17,21℃下的长期层间剪切强度。

To promote the durability of glass fiber reinforced ploymer(GFRP)bars,a thin layer of carbon fiber reinforced polymer was wrapped around the internal GFRP bars.The effects of distilled water,strong alkali solution,alkalescent solution,and saline-alkaline solution on the water diffusion and interlaminar shear strength of GFRP and HFRP bars were investigated.It compared with the cement mortar-covered FRP bars in distilled water and seawater.The results showed that in the case of the strong alkaline solution with pH 13.4 and saline-alkaline solution,the saturation water absorption of HFRP was less than that of GFRP.The retention interlaminar shear strength of HFRP bar was larger than GFRP bar,and the carbon fiber coat delayed the degradation of the internal GFRP.In the case of distilled water and alkalescent solution with pH 12.7,the saturation water absorption of HFRP was larger than that of GFRP.The degradation of interlaminar shear strength for HFRP bars was more severe than GFRP bar at 60℃.Trends of the variation of interlaminar shear stregnth and the failure modes of the cement mortar-covered FRP bars in distilled water and seawater were similar to the bare FRP bars in distilled water and alkaline solution with pH 12.7.The long-term interlaminar shear strength of GFRP and HFRP bars at 4℃,17℃and 21℃were predicted according to the Arrhenius theory.