Sun Zizhou, Li Xianjing, Liu Chao
College of Civil Engineering, Tongji University, Shanghai 200092, China.
Lin Tung-Yen & Li Guo-Hao Consultants Shanghai Co., Ltd., Shanghai 200437, China.
Materials (Basel). 2024 Sep 23;17(18):4675. doi: 10.3390/ma17184675.
In recent years, there have been an increasing number of examples of using ultrahigh-performance concrete (UHPC) as a pavement layer to form an ultrahigh-performance concrete-normal concrete (UHPC-NC) composite structure to improve the bearing capacity of bridges. In order to study the flexural performance of this kind of structure, this research studied the flexural performance of UHPC-NC composite slabs, with UHPC in the compression zone, using experiments, numerical simulation, and theoretical analysis. The results showed the following. Firstly, after the UHPC-NC interface had been chiseled, there was no obvious slip between the two materials during the test, and the composite plate was always subjected to synergistic stress. Secondly, the composite slabs in the compression zone of the UHPC were all subjected to bending failure, and the cooperative working performance of each part under the bending load was good, indicating that the composite slab had a unique failure mode and a high bearing capacity. Thirdly, increasing the thickness of the UHPC significantly improved the flexural capacity of the composite plate, and the maximum increase was about 15%. Increasing the reinforcement ratio of the tensile steel rebars also had an increasing effect, with a maximum increase of about 181%. Finally, the proposed formula for calculating the flexural capacity of composite slabs with UHPC in the compression zone could accurately predict the bearing capacity of said slabs. The calculated results were in good agreement with the experimental values, and the error was small.
近年来，将超高性能混凝土（UHPC）用作路面层以形成超高性能混凝土-普通混凝土（UHPC-NC）复合结构来提高桥梁承载能力的实例越来越多。为研究此类结构的抗弯性能，本研究采用试验、数值模拟和理论分析的方法，对压区为UHPC的UHPC-NC组合板的抗弯性能进行了研究。结果表明：第一，凿毛UHPC-NC界面后，试验过程中两种材料之间未出现明显滑移，组合板始终承受协同应力。第二，UHPC压区的组合板均发生弯曲破坏，各部分在弯曲荷载作用下的协同工作性能良好，表明组合板具有独特的破坏模式和较高的承载能力。第三，增加UHPC厚度显著提高了组合板的抗弯能力，最大增幅约为15%。增加受拉钢筋配筋率也有增强作用，最大增幅约为181%。最后，所提出的计算压区为UHPC的组合板抗弯能力的公式能够准确预测该类组合板的承载能力。计算结果与试验值吻合良好，误差较小。
