Experimental study of prefabricated wedge anchors for large diameter GFRP bars

The single large-diameter GFRP bar cannot anchor due to the large body-surface ratio. Most existing studies adopt the method of increasing the effective anchoring length, which increases the anchoring cost and the volume occupied by the anchor. This paper proposes a smaller prefabricated wedge anchor and establishes the relevant mechanical and finite element models . There is a taper angle difference between the wedge and the sleeve of the new anchor. The bar is subjected to uniformly varying compressive stresses during loading. According to the finite element results, the anchors are made, and used for static tensile test for the GFRP bars with a diameter of 32 mm. The results show that the taper angle difference and the inner slope angle are positively correlated with the ultimate load of the anchors. However, excessive taper angle difference can cause the wedge to pull apart. Excessive inner slope angle can cause too little clamping force on the bar, which leads to bar slippage. When the sleeve length is 235 mm, the optimum inner slope angle can be taken as 5.5° and the taper angle difference as 0.5°. The failure mode of the GFRP bar is dominated by fiber rupture . The ultimate load capacity is 629.4 kN, and the anchor efficiency is 135 %. The new anchor can move the complex stress state to the free end, alleviating the shear effect at the loading end and giving full play to the tensile capacity of the GFRP bar with a large diameter.