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About:
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The force-transfer mechanism is based on bond stresses provided by binding organic materials. Both ribbed bars and threaded rods can be used and a change of the local bond mechanism can be appreciated experimentally. In ribbed bars, the resistance is prevalently due to the shear behavior of concrete between the ribs whereas for threaded rods friction prevails (see also anchorage in reinforced concrete).[9] Bonded anchors are also referred to as adhesive anchors[ or chemical anchors. The anchoring material is an adhesive (also called mortar) usually consisting of epoxy, polyester, or vinyl ester resins. The performance of this anchor's types in terms of 'load-bearing capacity, especially under tension loads, is strictly related to the cleaning condition of the hole. Experimental results showed that the reduction of the capacity is up to 60%. The same applies also to the moisture condition of the concrete, for wet concrete the reduction is 20% using polyester resin. Other issues are represented by high-temperature behavior and creep response.
Screw anchors
The force-transfer mechanism of the screw anchor is based on concentrated pressure exchange between the screw and concrete through the pitches.
Plastic anchors
Their force-transfer mechanism is similar to mechanical expansion anchors. A torque moment is applied to a screw that is inserted in a plastic sleeve. As the torque is applied the plastic expands the sleeve against the sides of the hole acting as an expansion force.
Powder-actuated anchors
They act by transferring the forces via mechanical interlock. This fastening technology is used in steel-to-steel connections, for instance, to connect cold-formed profiles. A screw is inserted into the base material via a gas-actuated gas gun. The driving energy is usually provided by firing a combustible propellant in powder form. The fastener's insertion provokes the plastic deformation of the base material which accommodates the fastener's head where the force transfer takes place.
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