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Anchor Bolts Has Limitations
Aug 16, 2017

Chemical anchor is a new type of anchor after the expansion of the anchor bolt, Anchor Bolts through a special chemical adhesive, the screw cease fixed in the concrete substrate drilling, in order to achieve the anchor of the composite parts. Due to the small size of the chemical anchor on the market, and the specification of the chemical anchor depth of the anchor also has a clear requirement,Anchor Bolts making the chemical anchor in some areas with high seismic rating of the application has limitations.

Chemical anchorage and chemical anchorage anchoring principle is basically the same, is the use of high-strength structural adhesive to pull the bar and reinforced concrete bonded together, Anchor Bolts making it a whole. But their difference is that chemical anchorage and screw due to the length of unrestricted, and cast-in-place concrete reinforcement similar to the destruction of the shape easy to control, Anchor Bolts generally can be controlled for the anchor steel damage, it is suitable for static and seismic fortification ≤ 8 degrees of structural components and non-structural components of the anchor connection.

However, the use of chemical anchors only need to consider the anchor substrate thickness, Anchor Bolts group anchorage spacing and the minimum margin requirements, to avoid the installation of concrete when the anchor to produce greater damage to enhance the anchorage of the substrate damage when the carrying capacity and safety reliability.

In addition, the reinforcement technology is only applicable to the reinforced concrete structure reinforcement, and not suitable for the structure of the concrete structure and the reinforcement ratio is too low structural reinforcement, because the anchor bar technology is mainly applied to connect the original structural components and new components, This connection can only be achieved if the original component concrete has a normal reinforcement ratio and sufficient stirrups.

Insulation anchor by the expansion of the disc with the casing and expansion components, Anchor Bolts expansion casing material is generally polyamide, polyethylene or polypropylene plastic, the expansion of the pieces are mostly galvanized metal nails. When used, first insert the plastic sleeve into the borehole, then tap or screw the metal screw. The expansion sleeve end in the drilling expansion and compression to produce friction; expansion end section is greater than the hole, but also the formation of a certain mechanical locking effect, Anchor Bolts by the role of tensile force in the expansion of the shear force. Different types of anchors have different frictional and mechanical locking forces. If the main force of the percussion anchor is the friction force, Anchor Bolts and the main force of the knotting insulation anchor is the mechanical locking force.

Insulation anchor bolt fixed in the grass-roots wall, when it is tension, the anchor bolt expansion end and the base material to form external friction and mechanical locking force. Anchor Bolts Plastic sleeves and metal screws produce internal friction, the sleeve has a tension. The following relationships are satisfied between the various forces.

The size of the external friction and the friction coefficient of the contact surface, with or without sliding particles, the compressive strength of the base material,Anchor Bolts the diameter, the total length of the expansion section and other factors. The greater the friction coefficient, the drilling is about clean, the higher the compressive strength of the base material, the larger the diameter, Anchor Bolts the longer the total length of the expansion section, the greater the external friction.

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