Development of intermediate anchoring device for PC tendons using Highly Expansive Material and its anchoring mechanism

作者提出的高膨胀材料锚固法，在预应力混凝土结构中是一种非常有效的中间锚固方法。在这项研究中，方便的HEM中间锚固装置已被新开发和报告。进行了HEM锚具对预应力筋的锚固性能试验，并在此基础上利用剪切传递力学对HEM锚具的锚固机理进行了研究。引入非线性微分方程组，假设HEM层为剪切弹簧，并进行了数值分析。数值模拟结果与实验结果吻合较好。此外，还澄清了钢套管的标称长度要求，以牢固地夹紧钢绞线的屈服点。此外，还提出了高能电磁中间装置的设计概念。

The anchoring method using Highly Expansive Material (HEM) , which has been developed by the authors, is confirmed that it was very useful for the intermediate anchoring method in prestressed concrete structures using prestressing tendons. In this study, the handy HEM intermediate anchoring device has been newly developed and reported. The anchoring performance tests for prestressing tendons with HEM anchors were carried out, and the HEM anchoring mechanism, based on the experimental results was investigated using shear transfer mechanics. Nonlinear simultaneous differential equations were introduced, assuming that HEM layer behaves as shear spring and the numerical analyses were carried out. It was found that the results of numerical simulation agreed well with the experimental results. Also, it was clarified that the nominal length requirement for steel sleeve to grip firmly up to yield point of steel strands. Moreover, the design concept of HEM intermediate device was also proposed.