Experimental Determination Of The Pull-Out Strength Of Cast-In Lifting Inserts In Precast Hollow-Core Plank
Date of Award
Master of Science (MS)
Hollow-Core precast plank is a commonly used building component. The
common method to lift and erect these planks is through the use of slings. This method
has several drawbacks and has spurred on the current effort to investigate and determine
the capacity of lifting inserts post-installed into the top of precast hollow-core planks.
The insert that was studied is the P-52 "Swift Lift" Insert supplied by Dayton-Superior.
Physical testing of 16 inserts was done to aid in determining the tensile capacity
of the insert. The insert was a 3/4" diameter steel insert by 5 1/2" long and it was post
installed using non-shrink grout into the top of a hollow-core plank shortly after it was
extruded. A literature review was also performed to further analyze the insert and to
formulate analytical expressions capable of reliably predicting this tensile (pull-out)
capacity of the insert.
The testing resulted in an average measured tensile capacity of 13.8 kips with a
standard deviation of 1.85 kips. Our predictive model gave us a capacity of 12.33 kips
which is within one standard deviation from the average measured capacity. A factor of
safety of 2.2 was also calculated and developed. When we apply our factor of safety to
our measured tensile capacity we obtain a recommended capacity of 6.2 kips.