Lifting insert failure can be avoided by correct engineering and installation combined with correct lifting procedures and supervision. Recommended control or prevention measures applying inappropriate shock loading when lifting or moving the concrete element due to poor rigging practices, panel handling or panel preparation (i.e.
using defective lifting inserts or inserts with insufficient strength.incorrect slinging configuration for the lift.inadequate concrete compaction (particularly around the lifting insert).the use of the wrong type of lifting insert.the use of the incorrect type and model of lifting clutches for the specific lifting insert.inadequate concrete strength and curing times.Therefore the nominal anchor capacity marked on the anchor head, may not be achievable.įactors resulting in failure include the following: Where anchors are located in the edges of thin elements, the failure of the concrete surrounding the anchor may limit the working load. Diagram 2 shows typical head markings on inserts.įailures can occur when anchors do not meet the design engineer's specifications for the element to be lifted or are incorrectly installed. 'Hairpin' plate inserts for edge lifting, with and without a hole for attaching extra reinforcing.ĭiagram 1 shows three examples on the above listed common types.There are two common types of proprietary lifting inserts: Concrete elements include a wide range of products including wall and floor panels, bridge beams, road barriers and culverts.Ī compatible lifting clutch, designed for use with a particular lifting insert is attached to lift the concrete elements into place. The potential risk to life from failed lifting inserts can be considerable due to the large size and weight of some concrete elements involved. These incidents include failure of the concrete surrounding the lifting insert and failure of the insert itself. In Queensland there have been failures of cast-in lifting inserts in concrete elements. The purpose of this safety alert is to help minimise the likelihood of lifting insert failure in tilt-up and pre-cast concrete elements. Lifting inserts are specially designed and manufactured items, of controlled strength and ductility, which are cast into concrete elements for the purpose of lifting.