GFRP肋式剪力连接件受力性能对比试验研究

摘要

剪力连接件是保证GFRP混凝土组合梁／板中两种不同材料共同工作的重要构造，设计了矩形肋和T形肋两类GFRP肋式剪力连接件，进行了3组共8个GFRP肋式剪力连接件的推出试验，包括：矩形肋开孔、T形肋开孔、T形肋不开孔3组GFRP肋式剪力连接件，得到了其破坏形态、极限承载力、荷载滑移曲线及荷载应变变化规律，重点研究肋内开孔及肋的截面形式对GFRP 肋式剪力连接件受力性能的影响。试验结果表明：GFRP 肋式剪力连接件的破坏形态均为混凝土劈裂破坏；对比矩形肋开孔试件，T形肋开孔试件强度高、延性好；对比T 形肋不开孔试件，T 形肋开孔试件强度与延性均能提高。基于试验结果，建立了考虑肋内开孔及肋截面形式影响的GFRP 肋式剪力连接件极限承载力计算公式，拟合得到了GFRP肋式剪力连接件的荷载滑移曲线上升段的理论模型，建立了其抗剪刚度计算公式。%Shear connectors are the important detailings affecting the mechanical properties of GFRP-concrete composite beams/decks.Rectangular rib and T-type rib GFRP shear connectors are put forward to improve the interfacial bond properties between GFRP and concrete.Eight push-out tests are conducted to evaluate the mechanical behaviors of two rectangular perforated rib GFRP shear connectors and three T-type perforated rib GFRP shear connectors,as well as three T-type rib GFRP shear connectors.The failure patterns,ultimate bearing capacities, load-slip behaviors and load-strain regularities are obtained by contrast tests.Results show that T-type perforated rib GFRP shear connectors show higher strength and better ductility than rectangular perforated rib GFRP shear connectors,and T-type perforated rib GFRP shear connectors show higher strength and better ductility than T-type rib GFRP shear connectors.An empirical equation to predict the ultimate shear resistance is proposed and validated by the experimental data.Idealized load-lip models and equations to predict the load versus slip relationship for all specimens areproposed.Curve fittings are performed to find fitting parameters for all tested specimens and the resultsshow a very good correlation with those of the experiments.An empirical equation to predict the shearrigidity is proposed.