apron at primeter grade beams

huangyhg

apron at primeter grade beams
there is an ambiguity encountered in a design review.
a couple of aprons at entrance doors and an apron at truck door are sketched with dowels connecting aprons and the grade beams. the dowels seems not necessary to me. i used a detail before with just a cold joint, the apron slab was 1/2" lower than the grade beam at the interface where a l2x2x1/4 ange was embedded around the grade beam.
from my view, the dowels may have adverse effect when frost heave happens. what do you think?
thanks for input.
i usually use dowels at mandoors and oh doors with the steel going into the middle of the apron slab.  this helps prevent movement at that interface.
dik