钢-UHPC组合桥面板横向负弯矩区受弯性能研究

TRANSVERSE FLEXURAL BEHAVIOR OF STEEL-UHPC COMPOSITE DECK UNDER HOGGING MOMENT

为明确横向负弯矩作用下,剪力键形式、接缝设置情形、配筋率和钢混界面黏结状态等参数对钢-超高性能混凝土(ultra-high-performance concrete,UHPC)组合板受力性能的影响,完成了8块组合板局部足尺模型静力弯曲试验及有限元参数分析。试验结果表明:开孔板(perfobond leiste,PBL)试件的名义开裂强度(对应最大裂缝宽度为0.05 mm)较栓钉试件提高16.8%;矩形齿缝试件的名义开裂强度较整浇试件降低16%~23%;UHPC层钢筋配筋率从1.96%增加到2.82%时,名义开裂强度提高16.2%;钢板-UHPC界面涂油除黏PBL试件的初裂强度和名义开裂强度较界面黏结试件分别降低10.1%和5.8%。数值分析结果表明:PBL贯穿钢筋的存在、PBL和栓钉间距的减小能有效提高组合板的开裂后刚度;PBL开孔钢板上的孔径和孔间距对组合板的受力性能影响较小。

To investigate the effects of shear connector types,wet joint,reinforcement ratio,and bonding state in the steel-concrete interface on transverse flexural performance of steel-UHPC(ultra-high-performance concrete)composite deck under hogging moment,eight local full-scale composite decks were tested under static bending,and the parametric study was performed by the finite element method.The test results show that:compared with the specimens using studs,the nominal cracking strength of those using PBL(perfobond leiste)connectors increases by 16.8%.Compared with the integrally cast specimens,the nominal cracking strengths of the specimens with a rectangular-tooth-shaped wet joint decrease by 16%-23%.When the reinforcement ratio in UHPC layer from 1.96%to 2.82%,the nominal cracking strength of the specimens increases by 16.2%.Compared with the specimens with bonded steel-UHPC interface,the initial and nominal cracking strengths of those with the unbonded interface decrease by 10.1%and 5.8%,respectively.The results from the parametric study reveal that:adding perforating rebars in PBLs and decreasing the space of PBLs or studs can effectively improve the post-cracking stiffness of composite decks,and the diameter and space of the hole in PBLs have little effect on the mechanical performance of the composite decks.