A flat type anchorage system for short tendons with low prestress wedge draw-in loss

Abstrakt

Currently, there are drawbacks to the prestressing anchorage products used in prestressed concrete bridges, including significant anchorage draw-in during tensioning, inconveniences during construction, anchorage failure during usage, and operation subject to human interference. In order to overcome these unfavorable factors, a flat low draw-in anchorage system was developed through scheme design, selection, finite element analysis and trial production test. By adjusting the jacking force, this method uses a wedge-shaped structure in the shape of a jacking pad to guarantee that the draw-in value is within 1 mm. Slow bevelled contact, which has high self-locking properties and improves the contact surface while lowering compressive stress, is used between the pad plate and the flat low draw-in anchorage plate at a small angle of rise. Through the structural form of jacking the mat plate, jacking it into place at one time, and quantitatively controlling the value of jacking force, the system achieves standardized construction and reduces errors in human operation. The wedge anchorage system performs exceptionally well in terms of safety under simulated operating conditions, according to finite element analysis. After the fatigue test verification study, there was no fatigue damage to the anchorage parts, and the prestressed tendons were not broken. In the meantime, the sealing test revealed that there was no breakage of the anchorage’s components, and that there were no leaks or water stains inside the tendons or the anchoring itself. This system offers a solid assurance against girder deflection, web cracking in pre-stressed concrete bridges, and other ailments.