dowel-only connection strength

huangyhg

dowel-only connection strength
i have a client who wants to release a pt slab from a cmu wall along the full length of the wall with (2) layers of 10 mil polyethylene.  this would seem to change my shear friction capacity of the joint.  aci addresses monlithic, roughened and smooth-formed, but not double plastic sheeting.  this client suggested that the "dowel-only bearing strength might be used to assign a lower capacity to this shear connection.  
nds seems to present that there could be significant shear capacity by merely considering the bearing of the dowel against the concrete.  what i need though is the dowel-only shear capacity of the two pieces of concrete, not wood and concrete.
does anyone know where i might find some research or testing which could be used to assign a strength to this type of connection?