Briefing Of System
Ⅰ. JHM high-strength prestressed anchorage systems
JHM high-strength prestressed anchorage systems are rational in design, artistic in appearance and easy in construction and have following features:
1. They are suitable for steel stranded wires of strength grade up to 2000;
2. The anchorages conform to FIP93 Suggestion on acceptance of post-tensioned prestressed system and GB/T 13470-2007, have excellent static load and fatigue anchoring performances and reach domestic advanced level;
3. The optimized clip release taper angle and tooth-shape will reduce the damage of steel stranded wires by stress concentration;
JHM high-strength prestressed anchorage systems are rational in design, artistic in appearance and easy in construction and have following features:
1. They are suitable for steel stranded wires of strength grade up to 2000;
2. The anchorages conform to FIP93 Suggestion on acceptance of post-tensioned prestressed system and GB/T 13470-2007, have excellent static load and fatigue anchoring performances and reach domestic advanced level;
3. The optimized clip release taper angle and tooth-shape will reduce the damage of steel stranded wires by stress concentration;
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Ⅲ. Experiment
In accordance with Chinese standard GB/T 14370-2007 Prestressed bar-purpose anchorage, clamps and connectors and FIP93 Suggestion on acceptance of post-tensioned prestressed system the test-purpose steel stranded wire is grade 1860MPa and grade 2000MPa 15.24mm steel stranded wire and the limit tensile force of test parent wire is 275.5kN and 283～286kN respectively. The reliable product quality is guaranteed through great amount of static load experiments, fatigue experiments and cyclic-load experiments. 1. Static load experiment Great amount of static load experiments are made during the forming process and the experiment results show that anchor efficiency coefficient and elongation of anchorages meet the requirements specified in FIP93. During the experiment process, the clip follows smoothly, steel stranded wires rarely cut off or rupture, and they usually neck. There is no crack, inversed tooth or broken teeth on the retracted slip and the clamp marks on the steel stranded wires are clear and uniform. Hence, the anchorages have excellent static loading capacity. 2. Fatigue experiment The optimal-designed JHM anchorages have not only good static loading capacity but also excellent fatigue performances. The fatigue test has satisfactory results and after 2 million cycles there is no breaking of wire or rupture of clip. 3. Cyclic-load experiment JHM 15-1, 5, 6, 8, 12 anchorages are subjected to cyclic-load test, the upper limit and the lower limit of the stress is 80% and 40% of the standard tensile strength of the steel stranded wires respectively, and after 50 cycles there is no breaking or slippage of wire or rupture of clip and the results meet requirements of the standard. |