带T型肋的槽形GFRP-混凝土组合板受力性能试验研究

Experimental Study on the Mechanical Properties of Slotted GFRP Plate with T-shaped Ribs and Concrete Composite Slab

为研究界面处理质量对带T型肋槽形GFRP-混凝土组合板抗弯性能的影响,进行了4块组合板的静力试验.组合板的界面处理方式为不涂胶、涂胶、涂胶+撒砂、涂胶+撒砂+机械连接,其中机械连接方式是将钢筋穿过GFRP板T形肋的开孔形成.试验结果表明,不涂胶组合板由于界面粘结强度很低,破坏形式为GFRP板与混凝土的界面滑移破坏;其余组合板破坏形式均为剪跨区混凝土出现斜裂缝后的剪切破坏.相较于不涂胶的试件,组合界面采用涂抹环氧胶作为连接方式的试件,其承载能力提高了80%,对于采用涂胶+撒砂+机械连接的组合板,其承载力比采用涂胶和涂胶+撒砂的组合板要高出13.8%,破坏时表现出一定的“塑性”特征.在试验结果的基础上,考虑不同界面形式的粘结-滑移本构关系模型,建立了组合板有限元分析模型,分析了组合板的荷载-挠度曲线及荷载-应变曲线.计算结果表明,预测的极限荷载、GFRP板及混凝土的应变值与试验值吻合较好.

To study the effect of interface treatment quality on the flexural behavior of GFRP-concrete composite slabs with T-shaped ribs,four composite slabs were tested statically.The interface treatment mode of the composite slab was no gluing,gluing,gluing+sanding and gluing+sanding+mechanical connection.The mechanical connection method was to pass the steel reinforcement through the opening of T-shaped ribs of GFRP slab.The test results show that the failure mode of the composite slab without gluing was the interface slip failure of GFRP slab and concrete due to the low bond strength of the interface,and the other failure modes of the composite slab were the shear failure of the concrete with inclined cracks in the shear span area.Compared with the specimens without glue,the load-carrying capacity of the composite interface with epoxy adhesive was increased by 80%,the load-carrying capacity of the composite slab with gluing+sanding+mechanical connection was 13.8%higher than that of the composite slabs with gluing and gluing+sanding,and it also shows certain plasticity when it was damaged.By the test results,considering the bond-slip constitutive model of different interface forms,the finite element analysis model of composite plate was established,the load deflection curve and load strain curve of composite slab were analyzed.The results show that the predicted ultimate load,the strain values of GFRP slab and concrete were in good agreement with the test values.