基于UHPC湿接缝的C40与C50桥面板拼宽受弯性能研究

Research on Bending Performance of C40 and C50 Bridge Deck Widening Based on UHPC Wet Joints

摘要:

为研究连接新旧桥面板的超高性能混凝土（UHPC）湿接缝的受力性能，通过1块现浇整体板和2块UHPC拼宽桥面板的抗弯试验，分析了拼宽构造及横向受拉钢筋直径等对桥面板抗弯性能的影响，得到了极限荷载、荷载-位移曲线、钢筋应变曲线、接缝截面混凝土应变曲线。结果表明：现浇整体板的极限荷载为733.6 kN，UHPC拼宽桥面板在钢筋直径相同的情况下极限荷载为现浇整体板的92.7%；UHPC拼宽桥面板受拉钢筋直径由6 mm增加至8 mm，极限荷载由578.9 kN增加至680.3 kN，提升17.5%。UHPC拼宽桥面板表现出良好的抗弯性能，增大横向受拉钢筋直径可提高桥梁拼宽结构的抗弯性能。

Abstract:

To study the mechanical behavior of ultra-high performance concrete (UHPC) wet joints connecting new and existing bridge decks, the bending tests are conducted on one cast-in-place monolithic slab and two UHPC widened bridge deck slabs to analyze the effects of the widening construction and the diameter of transverse tensile reinforcement on the flexural behavior of the bridge deck slabs. The parameters such as ultimate load, load?displacement curves, reinforcement strain curves and concrete strain curves at the joint section are obtained. The results show that the ultimate load of the cast?in?place monolithic slab is 733.6 kN. Under the same reinforcement diameter, the ultimate load of the UHPC widened bridge deck slab reaches 92.7% of that of the cast-in-place monolithic slab. When the diameter of the tensile reinforcement in the UHPC widened deck slab is increased from 6 mm to 8 mm, the ultimate load increases from 578.9 kN to 680.3 kN, representing an improvement of 17.5%. The UHPC widened bridge deck slabs exhibit good flexural performance, and increasing the diameter of the transverse tensile reinforcement can enhance the flexural performance of bridge widening structures.