Anchor bolts have the following types:
(1) Expansion anchor bolt
The expansion anchor bolt uses the relative movement of the cone and the expansion piece (or expansion sleeve) to expand the expansion piece. It produces an expansion extrusion force with the concrete of the hole wall, and produces pullout resistance through shear friction to achieve a component anchored to the connecting piece. Expansion bolts are divided into torque control type and displacement control type according to the different control modes of expansion force during installation. The former is controlled by torsion and the latter is controlled by displacement.
(2) A reaming anchor bolt
Reaming anchor bolt, referred to as reaming bolt or slotting bolt, is a kind of component that can be anchored to the connected part through re-cutting and re-punching the concrete pressure surface formed after the reaming and mechanical interlocking between the expansion and expansion head of the anchor bolt. The reaming bolt is divided into pre-reaming and self-reaming according to different reaming modes. The former is pre-cut and reaming with special drill; The latter bolt is equipped with a cutter, which can be slotted by itself when installed, and the slotting is installed once.
(3) Bond anchor bolt
Bonded anchor bolts, also known as chemical bond bolts, referred to as chemical bolts or bonded stork. It uses special chemical adhesive to fix the screw and inner thread pipe in the concrete base material drilling hole. It achieves the anchorage of the connector by the bonding and locking action between the binder and the screw and between the binder and the concrete hole wall.
(4) Chemical plant steel
Chemically planted bar, including reinforced bar and long screw, is a kind of post anchorage connection technology widely applied in engineering field in China. The chemical anchorage anchoring foundation is the same as the bonded anchor bolt, but the chemical rebar and long screw are not limited due to their length. It is similar to the anchorage of cast-in-place concrete reinforcement, and can be generally controlled as the failure of anchor steel. Therefore, it is suitable for the anchorage connection of structural members or non-structural members whose seismic fortification intensity is no more than 8.
(5) Concrete screws
The construction and anchorage mechanism of concrete screw is similar to that of wood screw. It is a hard sharp knife thread screw produced by rolling with special technology. In the installation, the straight holes of the smaller aperture are predrilled first, then the screws are screwed in, and the anti pulling force is generated by the bite of the thread and the concrete of the hole wall, and a component anchored to the connected parts is realized.
(6) Fastener
The fastener is a kind of anchorage driven by gunpowder. It combines the steel nail and the concrete as a result of chemical melting and clamping, so as to achieve the anchorage of the connected parts.
(7) Anchorage adhesive
Anchorage performance of chemical planted bar and bonded anchor bolt mainly depends on anchorage glue and construction method. Epoxy-based anchorage glue is the most widely used anchorage glue in China.
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