We're installing TZ2 wedge anchors. Our procedures state to measure the embedment depth prior to torque. Is this correct? The torquing will pull the bolt slightly out of the hole, so taking this measurement pretorque seems inaccurate.
Hi Alan,
The KB-TZ2 acts such that the nominal embedment is tied to its effective embedment- for a given diameter, specific nominal embedments yield specific effective embedments. You may notice this as you reference our technical data or ESR-4266.
The nominal embedment listed is the value the installer uses to measure the length of the KB-TZ2 going into the concrete prior to torquing. This way, the installer can measure the embedment correctly before they complete installation of the anchor. The KB-TZ2 is then hammered down to the correct nominal embedment depth (both nominal and effective embedment is achieved simultaneously since they are connected) and then torque to the required installation torque.
If the anchor was installed per the Instructions for Use (IFU) and the proper installation torque was applied, the anchor is drawn up into its wedges and should be set. The nominal embedment will change post-torquing, however, the effective embedment (which is where the wedges expand and push against the concrete and in turn establishes the capacity) will not if the anchor was installed per our IFU.
Best,
Sinan
