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Cracks in Masonry

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Old pedestrian bridge consisting of single web precast t-beam.  60'-0" span.  Abutments are rectangular (8'-0" wide to match the t-beam and 6'-0" long).  The front (bridge side) wall bears on a concrete gravity wall.  The side walls bear partly on the gravity wall and partly on a continuous strip footing.  The rear wall is on a strip footing.  All of the masonry is 8"x8"x16 CMU with no vertical or horizontal reinforcing and no grouted cells. 
The masonry in the abutments has cracks, including some with in/out of plane displacement.  The cracks appear to be caused by the fact that the original construction apparently ignored thermal effects and "locked" both ends of the single web t-beam into the front masonry wall.
I am correcting the expansion issue by providing expansion joints at each end of the bridge.  No problem there.  And the new expansion joints will significantly reduce the forces being transferred into the masonry.
The Owner (small town, so limited funds) wants to repair the masonry by patching the cracks with mortar.  Some of the cracks are 3/4" wide.  Can cracks that wide be adequately repaired with mortar?  Or should some type of pressure epoxy grouting be used?
Of course this bridge has historical significance, so the "tear down and replace" option is not available.

David Finley
M. David Finley, P.E., P.A.
2086 SW Main Boulevard - Suite 111
Lake City, FL  32025