Expansion anchors are undoubtedly the "main force" in electromechanical installation, curtain wall keel, pipe supports,  cable tray fixing. Within the realm of building anchoring, expansion anchors are currently the mainstream product.

Working principle

The tapered screw propulsion causes the sleeve tail to expand outward, thereby creating enormous friction  mechanical locking effect inside the borehole, firmly gripping the concrete substrate.

When installed properly, expansion anchors can provide long-lasting  reliable anchoring force.

Main use cases

Expansion anchors have a wide range of applications,  are especially suitable for the following working conditions:

Installation of mechanical  electrical equipment: fans, water pumps, air conditioning units, distribution cabinets, etc.

The base of the equipment needs to be fixed, requiring the anchor bolts to have strong tensile  shear resistance.

Building curtain wall keel: The connection point between the curtain wall columns, beams  the main structure, which requires high long-term stability  fatigue resistance of the anchor bolts.

Pipe  cable tray fixing: Medium  light expansion anchors are usually selected for the support  hanger system of water pipes, air ducts  cable trays.

Steel structure connection: The connection between steel column bases, steel beams  concrete foundations requires large-size expansion anchors to bear a large load.

How to distinguish between good  bad expansion anchors

The quality of expansion anchors on the market varies greatly. It is recommended to judge their quality based on the following four aspects:

Examine the material: High-quality anchor bolts typically use high-alloy, high-strength carbon steel for the bolt  sleeve, with surface treatments such as galvanizing  hot-dip galvanizing, resulting in strong corrosion resistance. Ordinary products, on the other hand, often use ordinary cold-drawn steel, which has a rough surface  is prone to rusting in high-humidity  high-temperature environments.

Examine the sleeve's workmanship: A good expansion sleeve has a uniform cut, proper heat treatment,  consistent expansion plate angles. Inferior sleeves have rough cuts, insufficient heat treatment,  are prone to cracking  uneven expansion during installation.

Examine the taper fit: The higher the precision of the fit between the tapered screw  the inner tapered surface of the sleeve, the more synchronized the expansion  the more evenly the force is distributed. You can also feel it by pushing  pulling: high-quality products have a certain damping feel, while inferior products feel loose  wobbly.

To assess actual performance, the most direct method is to take samples  conduct pull-out tests. High-quality anchors exhibit minimal displacement  no abnormal noise when reaching the design load; inferior anchors often slip off  cause concrete cracking before the load is met.

Choosing a qualified expansion anchor  following proper installation are essential to providing a truly long-lasting  stable guarantee for the project.

Editor | Ding Yi

Reviewed by Liu Bo  Zheng Yuehua

ZHONGMAO

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