SFTec’s distributor, Westek Enterprises (president Brent Neudorf, P.Eng.), was approached by a client for a concrete sandwich wall shop project. In order to clearly demonstrate the advantages of SFT-Bar, Westek set off on a testing procedure with the help of Duracon Concrete Corp (https://www.duracon.rocks/) to assess and evaluate the potential of GFRP for this type of project. 

The tests were scheduled to be held at Duracon and would replicate a sample of the project requirements to help the client make the best decision for this structure. In the context of the series of tests that were conducted, the following criteria were used:

• The panel’s dimensions are: 24 in wide x 20 ft long
• Panel is 3x6x3  concrete x eps foam x concrete
• Three 10 mm FRP tendons were used in top and bottom concrete width
• Blocks are 2000 lb ea.

To test the strength of the SFT-Bar in the concrete structure, 5 blocks (2000 lb) were added. The results were 7 in deflection but no tendon failure.  While there was no escape from the cracks (as it is perfectly normal when a structure is blasted with that kind of weight), it was very impressive to see that there was no tendon failure, still. 

When a 6th block was added, the panel failed. The failure was of a shear type near the support but, once again, no tension failure in the center of the panel was noted. 

These results were very satisfying seeing as no shear connectors were used in these panels. This was done on purpose to evaluate any shear strength effect from the bond of concrete to the EPS foam.

However, in the actual building structure, we would incorporate shear connectors of some sort which would strengthen the panel even more. 

Once the tests were done, the project was set in motion. With Westek’s engineering input regarding #SFT-bar, Duracon’s concrete expertise and Strongbuilt Construction (https://strongbuilt.ca/about) team, the sandwich wall shop project had all the right ingredients for absolute success!