CFRP预应力筋夹片式锚具的试验研究

传统的夹片式锚具应用于CFRP（Carbon Fiber Reinforced Polymer／Plastics）预应力筋时必须进行改进，改进后的夹片式锚具由凹齿曲面的夹片、锚杯、塑料薄膜以及薄壁铝套管等组成。在夹片式锚具设计过程中，首先通过锚具的静力分析，推导锚杯的应力公式，然后根据VonMises屈服准则确定锚杯的最小厚度，再由锚杯和夹片的几何关系得到夹片的几何尺寸。试验研究表明，当锚杯倾角为3。、夹片预紧力为100kN、铝片厚度为lmm、凹齿间距为12．85mm和凹齿深度为0．3mm时，夹片式锚具表现出较好的锚固性能，极限荷载达到了185kN，相应的锚固效率系数为96．4％。锚杯长度、锚杯倾角、夹片预紧力、凹齿间距、深度和宽度以及铝套管的厚度等试验参数，均对夹片式锚具的极限承载力及CFRP筋和夹片之间的滑移量有较大影响。锚杯应力的实测值与理论值吻合良好，验证了锚具应力分析的可靠性。极限荷载的计算式具有较好的适用性。

Experimental Study on CFRP Prestressed Bar Clamp Anchorage

The traditional clamp type anchor must be improved when applied to CFRP (Carbon Fiber Reinforced Polymer/Plastics) prestressed tendons. The improved clamp type anchor consists of concave toothed curved clamps, anchor cups, plastic films, and thin-walled aluminum sleeves. In the design process of clip type anchors, the stress formula of the anchor cup is first derived through static analysis of the anchor. Then, the minimum thickness of the anchor cup is determined based on the Von Mises yield criterion, and the geometric size of the clip is obtained from the geometric relationship between the anchor cup and the clip. Experimental research shows that when the inclination angle of the anchor cup is 3 °, the pre tightening force of the clip is 100kN, the thickness of the aluminum sheet is 1mm, the spacing between the concave teeth is 12.85mm, and the depth of the concave teeth is 0.3mm, the clip type anchor shows good anchoring performance, with an ultimate load of 185kN and a corresponding anchoring efficiency coefficient of 96.4%. The experimental parameters such as anchor cup length, anchor cup inclination angle, pre tightening force of the clip, spacing between concave teeth, depth and width, and thickness of the aluminum sleeve all have a significant impact on the ultimate bearing capacity of the clip type anchor and the sliding amount between the CFRP reinforcement and the clip. The measured values of anchor cup stress are in good agreement with the theoretical values, verifying the reliability of anchor stress analysis. The calculation formula for ultimate load has good applicability