Load Transfer Dowel - Size and Spacing??

[LTBGeek]

Hi folks,

I recently came to work for a well-established construction company, and their typical detail is 1/2" x 3" slick rods at 12" on center for use in construction (cold) joints in industrial slabs. I have never seen dowels this small (diameter or length) used for load transfer (my previous standard was 3/4" rods 12" long). Particular slab in question is 10" thick in industrial environment with heavy fork truck traffic. They are adamant that this is all they have ever used and that they've had no problems, but I cannot find any guidance that supports such small dowels. However, all of the articles I can find on load transfer dowels are from FHWA, presumably because they've done the majority of the testing, and our company's stance is that this research doesn't apply because an industrial slab with fork truck traffic is quite different from highway loading. Can anyone weigh in with their opinion, and also point me to any written guidance for dowel size, length and spacing for industrial slabs? I'm uncomfortable signing off on these, even though "they've always worked for us."

Thank you!!!

 

[OldDawgNewTricks]

You might want to check out the recommendations in ACI 360 Guide to Design of Slabs-on-Ground.

 

[LTBGeek]

Old Dawg this is exactly what I was looking for, and is much more in line with what I'm used to using. Pulling up and reading ACI 360, I believe that the 1/2" x 3" rods they are currently using are likely doing very little, and that aggregate interlock is more likely what is keeping these joints performing well. I am going to continue to push back that we need larger and longer dowels.

 

[TigerGuy]

What is the purpose of a dowel that is only 3 inches long?

 

[Tomfh]

That’s some short dowels!

300mm long dowels is what I’m used to.

I can imagine 3” dowels still working, albeit with higher localised stresses and much less margin for error.

 

[DayRooster]

A loaded fork truck has quite the concentrated load. Calc that next to a expansion joint with a dowel for old transfer and that’s a recipe for a bent dowel. Not even positive those small dowels would even bend though. Probably just crack the few inches of concrete and rotate.

But here a link to the calculation to check it. Hope this helps too.

https://www.steeltools.org/files/GRDSLAB.xls