海水海砂碱激发混凝土与FRP筋的粘结性能

Bond Performance Between Seawater Sea-Sand Alkali Activated Concrete and FRP Bars

为了探究海水海砂碱激发混凝土与FRP筋的粘结性能发展规律,推动新型绿色建筑材料的应用,本研究通过对碳纤维增强塑料(CFRP)筋/玻璃纤维增强塑料(GFRP)筋与海水海砂碱激发混凝土(SSASC)试件进行中心拉拔试验,研究了FRP筋种类、直径、锚固长度及混凝土强度、养护龄期等因素对FRP筋-SSASC试件的粘结性能的影响。基于现有文献和实验所得数据统计分析,表明碱激发混凝土(ASC)与FRP筋的粘结性能明显优于普通硅酸盐混凝土(OPC)。同时使用多元线性方程将试验数据代入拟合出适用的粘结强度预测公式。结果表明:粘结强度随FRP筋直径和锚固长度的增大呈减小趋势,其中随直径的变化趋势不明显;ASC30混凝土大多为拔出破坏,ASC60混凝土大多为劈裂/筋断破坏,且强度较高的混凝土的粘结强度也较高;随养护龄期的增加其粘结强度有所上升;OPC与FRP筋的粘结强度小于ASC;所得粘结强度经验公式与实验数据具有良好的相关性。

To investigate the bond performance between seawater sea-sand alkali activated concrete(SSASC)and carbon fiber-reinforced polymer(CFRP)/glass fiber-reinforced polymer(GFRP)bars,center pull-out tests were carried out at different FRP bars,FRP bars diameters,bond lengths,concrete strengths,and concrete curing ages.Based on the statistical analysis of existing experimental data,the bonding performance between alkali activated concrete(ASC)and FRP bars is significantly better than that of ordinary Portland concrete(OPC).The bond strength can be predicted by the corresponding empirical model.The results show that the bond strength decreases with the increase of FRP bars’diameter and bond length,and there is no significant change as the diameter changes.Concrete ASC30 is mostly destroyed in pull-out failure,while concrete ASC60 is mostly destroyed in splitting/reinforcement fracture failure,and the concrete with a higher strength also has a higher bond strength.The bond strength increases with the increase of curing age.The bond strength between OPC and FRP bars is less than that of ASC.In addition,the bond strength predicted by the empirical model is in reasonable agreement with the experimental data.