Development of a Mechanical Wedge–Barrel Anchor for CFRP Rods: Static and Fatigue Behaviors

Abstract

In this study, a mechanical anchorage for prestressed carbon fibre-reinforced polymer (CFRP) rods was proposed. The proposed anchorage consists of a steel barrel with a conical hole and three separate aluminium wedges that are in direct contact with the CFRP rod. The anchorage system relies only upon friction, without any adhesives required. The static and fatigue behaviours of the anchor were experimentally investigated according to the European guidelines for

FRP Cables to Prestress RC Beams: State of the Art vs. a Split Wedge Anchorage System

“…Recently, Heydarinouri et al [26] developed an anchorage that can be considered a combination of the system proposed by [25]. The main peculiarities are represented by (1) circular profiles for a barrel and wedge both made in aluminum; (2) insertion of fillets to the edges of the wedges in contact with the CFRP cable (φ = 8.0 mm, P u = 103 kN); and (3) barrel height and external diameter respectively equal to 80 and 45 mm.…”

“…Regarding the proposed anchorage, for both the SA and DA model, a DIC strategy has been adopted to monitor the field displacements of either the cable surface or the topmost part of the anchorage wedge. These parts of the system have been typically selected by authors [22,[24][25][26] as monitored zones of split wedge anchorages. Clearly, the monitoring systems to be adopted could include (Figure 15 and Table 9): (1) gauges (zones A and B to measure the relative slip between (a) cable and sleeve, (b) sleeve and wedge, (c) wedge and barrel; (2) strain gauges to measure barrel (zone C) and cable (zone E) strain; (3) LVDT between plates D and F: it is worth noticing that the obtained displacements include cable elongation and the aforementioned relative slip.…”

“…They derive from those used to prestress concrete elements and need to be adapted if combined with FRP cables. The wedge shape should be defined [22][23][24][25][26] in order to reduce the bond stress along the FRP cable: this is the purpose of the present work, which will concern the experimental validation of a new anchorage system, after discussing the main literature proposals.…”

A Split-Wedge Anchorage for CFRP Cables: Numerical Model vs. Experimental Results

“…The same goal was efficiently fulfilled by the anchorage device of Al-Mayah et al (2006) [27], who introduced a circular profile for the interface between barrel and wedges, which was proposed again by Heydarinouri et al (2021) [28]. The efficience of curved interfaces was also employed by Gribniak et al (2019) [29], who devised, with the help of the 3D-printing technique, a full shear-grip curved anchorage inspired by the Nautilus shell profile for CFRP strips.…”

“…T a breaking load 16% greater than the cable ultimate lo that no rupture occurred within 2.0 × 10 6 cycles, altho and cable occurred in some specimens. The proposed [44] in the Abaqus software [41] and parametric analys differential angles, between barrel and wedges, of 0.1°, (circular and straight) at the tip of wedges for a differe Heydarinouri et al (2021), similarly to [27], proposed and tested [28] a curved splitwedge anchorage (Figure 13) for CFRP rods (φ = 8 mm), but with aluminum wedges and removal of the sleeve between the cable and wedges. Tensile tests on the system returned a breaking load 16% greater than the cable ultimate load, while fatigue tests highlighted that no rupture occurred within 2.0 × 10 6 cycles, although slippage between the wedges and cable occurred in some specimens.…”