短焊钉布置对超高性能混凝土组合桥面板抗弯性能影响

Effects of Short Stud Arrangement on Flexural Behavior of Ultra-High Performance Concrete Composite Bridge Decks

摘要:

为考察短焊钉连接件布置对钢?超高性能混凝土（UHPC）组合桥面板抗弯性能的影响，进行了焊钉间距分别为200与300 mm的2种足尺节段桥面板试件弯曲荷载试验和基于UHPC塑性损伤模型的有限元参数化分析。试验结果表明：在部分组合桥面板中，焊钉间距由200 mm变为300 mm，UHPC开裂达0.05 mm宽时对应的荷载等级提升了12.5 %，主要贡献是钢?UHPC组合效应减弱。UHPC开裂达0.10 mm宽时的拉应变平均值为1 878×10^-6，占材料极限拉应变的59 %。参数化分析结果表明：焊钉间距由100 mm增大至400 mm导致组合桥面板弹性阶段抗弯刚度下降了14.1 %，但开裂荷载等级提升了84.2 %。短焊钉间距增大使部分组合桥面板结构受力趋向于更为经济，但需注意过大的焊钉间距会导致焊钉疲劳破坏。

Abstract:

In order to investigate the effects of short stud arrangement on flexural behavior of steel-ultra-high performance concrete （UHPC） composite bridge decks， flexural tests of two full-scale segmental bridge deck specimens with a stud spacing of 200 and 300 mm respectively were performed， and a finite element parametric analysis based on the UHPC plastic damage model was conducted. The test results show that， as the stud spacing of partially-composited bridge decks increases from 200 mm to 300 mm， when the UHPC cracking reaches up to 0.05 mm in width， the corresponding load increases by 12.5 %. The main contributor is the weakening of the steel-UHPC combination effect. The average tensile strain of the UHPC is 1 878×10^-6 as the cracking reaches 0.10 mm in width， accounting for about 59 % of the material ultimate tensile strain. The parametric analysis shows that as the stud spacing increases from 100 mm to 400 mm， the elastic bending stiffness decreases by 14.1 %， while the cracking load increases by 84.2 %. The increase of the short stud spacing makes the partially-composited bridge deck tend to be more mechanical-economical， but attention should be paid to the fatigue damage of the stud because of the too large stud spacing.