University Studies and Independent Research
While we think Squirter® DTIs are the easiest thing to install and inspect, and the jobsite feedback is nothing but positive, some independent verification goes a long way.
The University of Toronto studied the performance of Squirter® DTIs with the muscle being provided by the Ironworkers Local 721. In short, the Ironworkers performed our recommended Squirter® DTI Calibration Exercise (how much squirt is enough squirt) on 7/8" A325 bolt assemblies in a calibrated Skidmore-Wilhelm. Then tensioned these bolts (that were specially prepared to be measured ultrasonically) until they saw the calibrated amount of silicone emit from the Squirter DTI. The University then measured the bolt assemblies ultrasonically and the achieved clamp load was almost dead-on. The minimum required load for a 7/8" A325 bolt is 39,000 and the calibrated Squirter load was 45,000. The Ironworkers achieved an astonishing average of 45,600 pounds of tension!
Here's the University of Toronto report in summary form as delivered to the Research Council on Structural Connections (RCSC) June 2008 meeting:
Download Report in PowerPoint (2.5 MB pps) format
Download Report in PDF format The Florida DOT was interested in the advantages the Squirter® DTIs offered right from the get go. They, with the help of Keith & Schnars and Woodhopkins Erectors, put Squirter® DTIs up against their long time favorite, Turn-of-Nut, on the Beaver Street Bridge in Jacksonville, FL. Squirter® DTIs came out FAR ahead.
During an independent study, in conjuction with Keith and Schnars and Wood Hopkins Erectors, the FLDOT have used SQUIRTER® DTIs on the Beaver Street Bridge Project, and compared them to Turn-of-Nut. SQUIRTER® DTIs came out FAR ahead, according to the study trial.
Go to the trial results here
The trial highlights include;
- a dollar a bolt savings on installation (!!)
- 75% time savings for aerial bolting (!!)
- less installer fatigue
- immediate verification of bolt tension
- and less than 1% retighten work required
Check out the trial results for yourself in pdf format, as written by Keith and Schnars for the Florida DOT. Go to the trial results here
