Denso tape around anchor bolts
Denso tape around anchor bolts
(OP)
In steel structure part of our stadium project, the designer required anchor bolts of fully threaded. However, the contractor procured anchor bolts which are threaded at the ends only. So, they wrap the anchor bolts with denso tape along the unthreaded portion. They are using this procedure of denso tape on those anchor bolts which shall be subjected pre-tensioned of 75% of the specified design force after erection.
I am just newbie to this kind of system. Is this procedure of providing denso tape around anchor bolts really a practice in lieu to the full threaded anchor bolts? And is this really effective?
I am just newbie to this kind of system. Is this procedure of providing denso tape around anchor bolts really a practice in lieu to the full threaded anchor bolts? And is this really effective?






RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
Yes, exactly. Only that the bottom plate were not welded instead provided with nut on each side.
I'm bit confused because of the threaded shaft of anchor bolt against denso tape idea. Correct me if I'm, my personal impression is, having threaded shaft even make better contact on grout than the denso surface. So, why designer told that it was originally full threaded that denso tape can even be avoided.
RE: Denso tape around anchor bolts
These days, people are inclined to call out all-thread rod, which is a commodity piece, in 10' lengths. You cut it to length and it has threads on both ends for exactly your type of application. The alternatives would be spec’ing. a 24" long rod (xxx grade) then having a shop thread both ends, one end 4-5" long and the other end 2" long and then applying the washer and nuts on the correct end; or ordering an extra long bolt (not a stock item) and being content with a loose washer. But, both of these latter items are more expensive per foot than the all-thread, because of the extra steps involved. Then, to get proper tensioning and elongation you have to wrap all of them with some form of bond breaker. I don’t know what Denso tape is, but most any bond breaker will work. Obviously, the threads would cause more bond and trouble than a smooth rod, much like the deformations on rebar.
RE: Denso tape around anchor bolts
ANCHOR RODS (GENERAL)
ANCHOR RODS SHALL BE WELDABLE U/N
ALL ANCHOR RODS SHALL BE [3/4 | 19]%%C MIN U/N
3/4"%%C ANCHOR RODS SHALL BE FABRICATED FROM ROUND BAR x [20" | 24"] LONG U/N. THE BOTTOM OF THE BAR SHALL HAVE A 1" LONG UNC THREADED PORTION TO ACCEPT A HEAVY HEX HEAD NUT WELDED AT THE BOTTOM WITH 1/4" FILLET WELD 3/4" LONG. THE TOP OF THE BAR SHALL HAVE A 4" LONG UNC THREADED PORTION TO ACCEPT A HEAVY HEX HEAD NUT, AND WASHER. EMBEDMENT LENGTH SHALL BE 19" MIN. LENGTH OF PROJECTION SHALL BE 4"
Dik
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
"ACCEPT A HEAVY HEX HEAD NUT WELDED AT THE BOTTOM WITH 1/4" FILLET WELD 3/4" LONG"... welded at the bottom and never had a problem with location, but, will clarify my notes. Thanks
Dik
RE: Denso tape around anchor bolts
Might have been a once-in-a-lifetime occurrence but I've changed my drawings to show the weld symbol and not rely on just a note. I also ran into welds on top when there were no threads or too few threads showing below the nut. Again, maybe just a one-off deal.
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
Is the %%C about carbon content?
Can you describe some better ways? I'm curious to know more.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
Dik
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
RE: Denso tape around anchor bolts
Dik