TILT-UP CONSTRUCTION - Brock White

General andTechnical InformationThreePFourPGeneral and TechnicalInformationA ductile failure may occur in the insert. Coil type insertswill usually fail at a point just below the helically wound wirecoil. A small cone of concrete will usually be pulled out of theconcrete surface. This cone will have its apex at a point justbelow the coil. Its base diameter will be approximately twiceits cone height.“Headed” type inserts will exhibit a ductile failure throughthe shaft diameter of the insert.These failures usually occur in higher strength concreteor adequate embedments when the concrete resistance isgreater than the mechanical strength.Failures of this type are due to a definite overload beingapplied to the inserts. Such failures can be prevented bychoosing inserts of capacity suitable to job conditions or byincreasing the number of inserts used to lift the tilt-up panel.Coil Bolt/Coil Insert failurePWarning! When bolting coil type inserts, the bolt shouldalways extend at least the proper amount beyond thebottom of the insert coil. Failure to do this causes the entirebolt load to be transferred to fewer turns of the coil, causingan increased load per weld contact point. The coil will thenunwind much like a corkscrew, resulting in a prematurefailure.Insert SetbackMinimum CoilPenetrationSee page 29 for proper method of determining boltlengths.Insert PlacementTilt-up lifting inserts are generally categorized in two types,face lift and edge lift. Both types of inserts must be placedaccurately and positioned properly. Safe working load of theinsert may decrease considerably if the insert is notpositioned perpendicular to the bearing surface. All DaytonSuperior lifting inserts are designed for easy positioning andsecuring to the reinforcement steel.It is also important that all coil style lifting inserts beplaced so the depth of thread is constant throughout thejob, minimizing improper bolt engagement. Keep all liftinginserts free of dirt, ice and other debris that may interferewith hardware engagement.02-099