钢桥面UHPC铺装层的黏结性能试验研究

在钢桥面的铺装设计中,由于标高控制和自重控制要求,普通混凝土铺装层因厚度大、自重高难以满足设计要求,因此亟需薄厚度、高性能的铺装层,而超高性能混凝土(UHPC)是潜在可满足设计要求的铺装材料.但在循环交通荷载下,UHPC铺装层与钢板之间的黏结作用尚缺乏试验研究.研究开展了五点弯曲疲劳试验和剪切试验,研究UHPC钢桥面铺装层的黏结特性和抗疲劳破坏能力,并基于数值计算结果,将疲劳加载次数转换为标准轴载作用次数.研究发现,在标准车辆轮载作用下难以快速对试样产生损伤.即使试样黏结界面边缘开裂,稳定不变的变形也暗示裂缝并未扩展至内部,即试样内部损伤有限,仍然具有良好的承载力.含有栓钉的UHPC-钢桥面黏结界面的等效抗剪切强度为12.4 MPa左右,其破坏形式为栓钉的剪切破坏.UHPC与钢板之间协同作用十分显著,铺装后相对于无铺装的钢板刚度提升1倍左右.

Experimental Study on Bonding Properties of UHPC Paving Layer on Steel Bridge Deck

In the design of steel bridge deck pavement, due to the elevation control and self-weight control requirements, ordinary concrete pavement is hard to meet the design requirements because of large thickness and high self-weight. Therefore, it is necessary to need a thin-thickness and high-performance paving layer. The ultra-high performance concrete (UHPC) is potentially a suitable bridge deck pavement material. However, there is a lack of experimental study on the bonding effect between UHPC paving layer and steel plate in the cyclic traffic load. The fatigue bending test and shear test are studied. The bonding properties and fatigue failure resistance of UHPC steel deck paving layer are studied. And based on the result of numerical calculation, the fatigue loading times are converted to the standard axle load action times. The study shows that it is hard to quickly damage the specimen under the standard vehicle wheel load action. Even if the specimen bonding interface edge cracks, the stable and invariable deformation also suggests that the cracks have not extended to the interior, which is that the internal damage of the specimen is limited still with the good bearing capacity. The equivalent shear strength of the UHPC - steel deck bonding interface with studs is about 12.4 MPa. Its failure mode is the shear failure of the stud. The cooperating action between UHPC and steel plate is very obvious. Compared with the steel plate without pavement, its stiffness increases by about 1 times.