Performance of interface between TRC and existing concrete under a chloride dry-wet cycle environment

Textile-reinforced concrete(TRC)is suitable to repair and reinforce concrete structures in harsh environments.The performance of the interface between TRC and existing concrete is an important factor in determining the strengthening effect of TRC.In this paper,a double-sided shear test was performed to investigate the effects of the chloride dry-wet cycles on the average shear strength and slip at the interface between the TRC and existing concrete,also considering the existing concrete strength,bond length,textile layer and short-cut fiber arrangements.In addition,X-ray diffraction(XRD)technology was used to analyze the microscopic matter at the interface in the corrosive environment.The experimental results indicate that the interface performance between TRC and existing concrete would decrease with continued chloride dry-wet cycles.Compared with the specimen with a single layer of textile reinforcement,the specimens with two layers of textile with added PVA or AR-glass short-cut fibers could further improve the properties of the interface between the TRC layer and existing concrete.For the TRC with a single layer of textile,the average shear strength tended to decrease with increasing bond length.In addition,the strength grade of the existing concrete had a minor effect on the interface properties.

斜拉体系加固桥梁桥下连接件力学性能

针对斜拉体系加固梁桥下连接件具有承受剪压组合荷载、双剪切界面、粘贴钢板与螺栓锚固混合连接等受力特点,但力学性能及破坏模式不明确的缺点,通过Abaqus有限元方法建立了某桥下连接件的精确有限元模型,对其力学性能及破坏模式开展了研究。结果表明,各模型的最终破坏模式均为螺栓的剪切破坏,模型最终破坏位置分2类:胶层面处的螺栓剪切破坏和两钢板接触面处的螺栓剪切破坏。荷载作用下桥下连接件共存在4种承载力变化趋势,部分模型破坏前承载力出现明显的下降段。影响模型极限承载力的要素中仅单一要素变化时,极限承载力并不完全以单调趋势变化,即各要素间存在复杂的耦合关系。