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I have a question regarding the acceptability & use of Type F Barrier when small variances are in the construction detail.

Attached to this email are the drawings for:

1.) Illinois Type F Barrier Design Standard

2.) A marked-up drawing denoting the differences between the MoDOT standard and the Illinois standard

3.) The MwRSF Tested Type F Barrier drawing. 

As you can see from the marked-up comparison, there are a few different dimensional details between the 3 design types for the Type F Barrier.  Mainly the differences are bar placement and bar shaping. Would these small differences in those details play a factor in the performance of the Type F barrier when comparing it to the one that was tested by MwRSF?  Or would this be a judgement call on if it was close enough in the design to accept for use?  Any feedback would be greatly appreciated.

I looked at you proposed changes from the ILDOT barrier.

1. I think your use of the 1 ¼” diameter connection pin is an improvement and is more consistent with the MASH tested F-shape PCB.
2. I also am good with your use of the L-bars for the connection loops. Again, this is more in line with the as-tested system. Note that the as-tested system has a slightly different bar grade for the connection loops to prevent cracking or damage during the tight bends that are used to form the loops.
3. The minor differences in bar spacings should not be an issue and the additional stirrups noted should only further strengthen the barrier.

I don’t see anything here that would detract from the basic free-standing barrier performance a compared to the barrier we tested.

The anchor pockets and anchor pins are different than the anchored systems we have tested. We used 1 ½” diameter anchor pins and a different pocket shape. As such, the anchored barrier may perform differently.  

Thanks!