Development of Non-metallic Anchorage System for FRP Tendons

作者新开发了一种使用高膨胀材料的非金属锚固系统。本文的研究成果总结如下：(1)非金属锚具可由CFRP筋和环氧树脂砂浆制成。(2)双层CFRP螺旋筋可以抵抗高达40 Mpa的高膨胀材料的内部膨胀压力。在节距拥挤的情况下，采用CFRP螺旋箍也能有效抵抗筋的张拉力。(3)用CFRP筋/棒加固可以获得抵抗预应力所需的轴向刚度。从树脂砂浆灌浆的短期和长期位移和工作性的角度来看，配筋率以4~5%为宜。(4)非金属锚具受压极限荷载大于400kN，100kN左右的预应力是安全的。(5)预应力的减小主要是由于锚具端部CFRP筋的滑移造成的。但在实际应用中，当锚索长度较大时，滑移对预应力减小的影响可以忽略不计。(6)提出了一种实用的非金属锚具预应力体系。

The authors have newly developed a non-metallic anchorage system using highly expansive material. The results obtained in this study are summarized below.(1) Non-metallic anchoring devices can be made of CFRP reinforcement and epoxy resin mortar.(2) Double layr CFRP spiral reinforcement is able to resist the inner expansive pressure up to more than 40 MPa of highly expansive material. The CFRP spiral hoop inside with congested pitch is also effective to resist tensioning force of tendon.(3) Axial stiffness, needed to resist the prestressing force, can be obtained by reinforcing with CFRP strand/rod. Reinforcement ratio of 4-5% is found to be appropriate from the viewpoints short/long term displacement and workability of resin mortar grouting.(4) Ultimate load of the non-metallic anchoring devices in compression is more than 400 kN.The prestressing force about 100kN is safe.(5) The decrease of prestressing force is mainly caused by the slippage of CFRP tendon at the end of anchoring device. However, the influence of slippage on the decrease of prestressing force becomes negligibly small when the length of tendon will be much longer in practice.(6) The prestressing system with newly developed non-metallic anchoring devices is considered as a practical method.