Anchor Bolt Fixing

     Anchor bolts are used to connect structural and non-structural elements to the concrete. The connection is made by an assembling of different components such as: anchor bolts (also named fasteners), steel plates , stiffners. Anchor bolts transfer different types of load: tension forces and shear forces. A connection between structural elements can be represented by steel column attacched to reinforced concrete foundation. Whereas, a common case of non-structural element attached to a structural one is represented by the connection between a facade system and a reinforced concrete wall.

 

Mechanical Expansion anchors

 

A wedge anchor

The force-transfer mechanism is based on friction mechanical interlock guaranteed by expansion forces. They can be furtherly divided into two categories:

 

torque controlled: the anchor is inserted into the hole and secured by applying a specified torque to the bolt head or nut with a torque wrench. A particular sub-category of this anchor is called wedge type. As shown in the figure, tightening the bolt results in a wedge being driven up against a sleeve, which expands it and causes it to compress against the material it is being fastened to.

displacement controlled: usually consist of an expansion sleeve and a conical expansion plug, whereby the sleeve is internally threaded to accept a threaded element.