球扁钢肋钢纤维混凝土组合桥面板正弯矩受力性能试验

Experimental on positive bending behavior of composite bridge decks with steel-fiber-reinforced concrete and longitudinal bulb-flat ribs

针对一种采用80 mm厚钢纤维混凝土(SFRC)和球扁钢纵肋的新型组合桥面板,设计制作了两个组合桥面板足尺模型,进行了正弯矩加载试验,测试得到加载全过程结构变形和应变变化情况。采用截面弹塑性截面分析方法、线弹性分析方法和刚塑性分析方法计算了正弯矩承载力,并与试验结果进行对比。研究结果表明:组合桥面板在承受正弯矩荷载时位移延性系数为4.90~5.77,具有较好的延性;在承载能力极限状态下,组合桥面板正弯矩承载力由球扁钢受力控制,SFRC具有充足的抗压强度,提高混凝土强度对正弯矩承载力影响很小;截面弹塑性分析能较为准确地计算正弯矩承载力,适合用于组合桥面板设计计算。

In order to study the structural behavior and mechanism of the orthotropic steel-concrete composite bridge deck under positive bending,a composite bridge deck composed of 80 mm steel-fiber-reinforced concrete(SFRC)and longitudinal bulb-flat ribs was investigated by model tests.Two full-scale specimens were designed and fabricated.Positive bending tests were carried out and the variations of stiffness and structural strain during the loading process were obtained.The elastoplastic cross-sectional analysis method,linear elastic analysis method and rigid-plastic analysis method were used to calculate the positive bending resistance and the results were compared with the experimental results.It was found that the composite bridge deck has good ductility when it was subjected to positive bending.At the ultimate limit state,the positive bending resistance is governed by the stress bearing of the bulb-flat ribs and the SFRC has sufficient compressive strength.Increasing the compressive strength of SFRC has little influence on the positive bending resistance.The elastoplastic cross-sectional analysis is more accurate and applicable for the calculation of the positive bending resistance of the composite bridge deck.