un-bonded p-t in bridges
 

un-bonded p-t in bridges
i am not aware of any new bridge projects in the usa today that use un-bonded p-t in bridge decks - please correct me if i am wrong - if this is true, why? does the aashto/dot code/s prohibit its use?
historically, has unbonded p-t been used in bridge decks in the usa or other parts of the world, and if so, does anyone have project references?
by un-bonded p-t, i do not mean to include external p-t, rather greased and sheathed strand systems within concrete decks/elements etc.
thanks in advance.
ps those of you who frequent "p-t" and "bridge" forums, i apologize for repeating this thread here, but the "structural" forum appears to have a wider cross section of engineers whom may be able to repsond to this thread.