The installation of anchor bolts seems simple: drill holes, knock,  tighten nuts.

But these few steps conceal details that can cause the entire connection to fail. Have you encountered any of the following four mistakes during your construction process?

01. The aperture is incorrect; the size will have to be used as is.

If the drill bit wears down  the hole diameter is too small,  if the hole diameter is accidentally too large during drilling, forcing the expansion anchor bolt in will affect the final anchoring effect.

It is important to note that the diameter of the anchor hole must be strictly matched with the specifications of the anchor bolt.

An unsuitable orifice diameter will ultimately prevent the expansion plate  expanding properly, resulting in a significant decrease in frictional anchoring force  insufficient anchor bolt bearing capacity.

Correct procedure: Replace with a new drill bit  re-drill the hole;  seal the original hole  change the installation position.

02. Installed directly without cleaning the holes.

The dust generated during drilling remains at the bottom of the hole  forms a lubricating layer when the anchor bolt expands, significantly reducing friction.

The correct procedure for cleaning the hole is as follows: blow air into the hole twice, brush the hole twice,  then blow air into the hole once more to ensure that the hole is clean  dry. This step takes about 30 seconds, but it is crucial for ensuring the anchoring force.

There was no air pump on site.

Use a hole cleaning brush to clean the hole back  forth at least 5 times to remove dust. Blow the dust out,  the force of the air blowing is important.

03 Tighten by feel, without using a torque wrench

Torque-controlled expansion anchors require a specified installation torque to expand properly.

If a strong operator overtightens the bolt, it will result in excessive torque  excessive slippage; if the operator is too weak  does  tighten it enough, the expansion bolt will  expand properly,  ultimately the bolt will fail to provide anchoring.

Correct method: Prepare a torque wrench  strictly follow the installation torque value in the product manual. Different specifications have different torque values  should  be mixed.

04. Drilling holes near the edge without checking the minimum margin.

If the distance between the anchor bolts installed near the edge  corner of the concrete is insufficient, the concrete is very prone to splitting failure  exhibits obvious brittle failure during pull-out.

Correct method: Each anchor bolt product has minimum edge distance  minimum spacing requirements. Before construction, you must check the product technical specifications to confirm them. You cannot estimate based on experience.

Ignoring any of the above points could result in a qualified anchor bolt  reaching half of its designed load-bearing capacity.

Edited by Ding Yi

Reviewed by Liu Bo

Official website丨www.zmwj.cn

Telephone丨0512-86162111