超高性能混凝土-普通混凝土组合梁桥界面抗滑移试验与分析研究

Testing and Analytical Investigation of Interface Slip Resistance of UHPC-NC Composite Beam

UHPC(超高性能混凝土)作为一种新型混凝土材料,具有抗拉压强度高、耐久性好、变形性能优异的特点。为克服UHPC生产工艺复杂、制作成本较高的缺点,提出一种UHPC主梁由工厂预制,NC(普通混凝土)桥面板现浇而成的新型组合桥梁。然而,UHPC-NC组合构件叠合面的力学行为是决定2种材料能否良好共同工作的关键因素。为了研究具有抗剪箍筋作为连接件的组合梁的界面抗滑移性能,对10组UHPC-NC叠合试件进行了推出试验,研究了抗剪箍筋的数量、结合面的粗糙程度、普通混凝土的强度等级、钢纤维的形态等因素对界面粘结强度的影响。结果表明配置一定量的抗剪箍筋、对界面进行凿毛处理、提高NC强度等级可以显著提高界面的抗剪极限承载力,而钢纤维的形态对承载力几乎没有影响。采用ABAQUS有限元软件对试验过程进行了分析,得到了一个典型试件的粘结滑移曲线及理论抗剪承载能力。实测结果与计算结果吻合较好,表明超高性能混凝土和普通混凝土叠合构件具有良好的协同工作性能。

as a new type of concrete material,UHPC(ultra high performance concrete)has high tensile strength,good durability and deformation performance characteristics.To overcome its complex production process,the shortcomings of high production costs,this paper proposes a new type of composite Bridges,whoes UHPC girder is prefabricated by factory,and NC(ordinary concrete)panel is casted in place.However,the mechanical behavior of UHPC-NC composite surface can be the key factor that decides the cooparative work of this two kinds of materials.In order to study composite interface' s slip resistance,10 groups of UHPC-NC composite specimens was launched for experiments to study the impact on the interface bonding strength of the amount of shear reinforcement,joint surface roughness,the strength level of the ordinary concrete and steel fiber morphological.Results show that the configuration of a certain amount of shear reinforcement,to cut wool processing,and improving the NC interface' s strength grade can significantly improve the ultimate bearing capacity of interface shear,and the figure of steel fiber will have little impact on bearing capacity.Testing process was analyzed using ABAQUS finite element software,and a typical bond-slip curve of the specimen and the theory of shear bearing capacity was acquired.The measured results and calculated results are in good agreement,which indicates that high performance concrete and ordinary concrete composite component has a good work performance.