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New anchor hole
Installed anchor |
When cell towers were first installed they rarely had to support a maximum amount of hardware and communication equipment attached to the top and sides. The engineering and design for the towers was usually based on a moderate amount of loading required for the limited demand for space. As time goes on more and more cellular communications equipment is added to the sides and top of the structures and the original structural specs and anchor design becomes inadequate.
To keep the tower in service and increase the equipment load, it is necessary to retrofit some towers with additional structural stiffeners and anchoring to protect against a wind load failure. Additional 2" x 9' long concrete threaded anchors were installed into the concrete base on this anchoring retrofit job.
Kelken Chemical Anchoring products Keligrout and Keligrit were used to secure the treated steel anchors to the concrete footing. Before installing the anchors the newly drilled holes were prepared with a scarifying tool to ensure that the interior surface of the hole would provide a sufficiently rough surface for the anchors to grab.
Once the hole is blown out with compressed air it is ready for the properly prepared Keligrit™ which can be poured or spooned into the hole. Next the anchor is pushed to the bottom of the hole and rotated to assure total wetting. The anchor is then left undisturbed for about an hour depending on the ambient temperature at the time of installation.
Keligrout is about 50% cured after the first hour and fully cured after 24 hours. At that time the anchors on this job were pull tested to 130,000 LBS with a hydraulic jack.
Cell Tower Retrofits specialists Tower Solutions LLC, was the contractor on this job.
