GFRP-混凝土组合连续板的静力性能试验研究

Experimental Investigation into Static Behavior of GFRP-Concrete Continuous Deck

为提高钢-混凝土组合梁桥桥面板的耐久性,研究GFRP(玻璃纤维增强复合材料)-混凝土组合连续板的变形及裂缝宽度,设计了3片负弯矩区具有不同钢筋配筋率的GFRP-混凝土组合连续板,并对其进行了对称加载试验,重点考察了连续板的破坏模式、变形、裂缝宽度和应变分布等力学特性.结果表明:3片连续板均发生了弯剪破坏;破坏时板端GFRP槽形板与混凝土之间无明显滑移;随着负弯矩区配筋的增强,连续板全过程变形减小;在钢筋屈曲前,连续板正负弯矩区的应变分布基本符合平截面假定.试验研究和理论分析结果的对比表明:可以采用现行桥梁规范中考虑混凝土开裂区域刚度变化的等效刚度计算GFRP-混凝土连续板的等效刚度,并通过文中计算方法获取连续板的变形;此外可以采用现行规范JTG D62—2004中钢筋混凝土的裂缝宽度计算方法计算连续板负弯矩区的混凝土裂缝宽度.

In order to improve the durability of steel-concrete composite beam bridge decks and investigate the deformation and crack width of glass fiber-reinforced polymer（ GFRP）-concrete continuous decks,three GFRP-concrete continuous decks with different reinforcement ratios in the hogging moment region were designed and then tested under symmetrical load. The failure mode,deformation,crack width and strain distribution of the three continuous decks were discussed. The results show that（ 1） all the three GFRP-concrete continuous decks fail with the diagonal shear failure,and there is no obvious slip between the GFRP channel slab and the concrete in the failure;（ 2） with the increase of the reinforcement ratio in the hogging moment region,the deformation of the continuous decks decreases in the whole process; and（ 3） the plane sections in the sagging and hogging moment regions remain plane before steel rebar yields. The consistency of the theoretical results with the experimental results demonstrates that the flexural equivalent stiffness of the GFRP-concrete continuous decks can be predicted by means of the existing bridge standard,and the deformation can be predicted through the proposed method in this paper. Besides,the crack width in the hogging moment region can be predicted by means of the existing standard JTG D62—2004.