The slab-girder type concrete bridge is one of the most common bridge types in practice.This type of bridge is built as cast-in-place reinforced concrete (RC) slab sitring on top of prestressed concrete (PC) girders,where the shear connectors are used to ensure full composite action between the concrete slab and girders,so they act as a unit.However,as observed from practice,the deck joints between adjoining spans have caused severe problems and concerns of bridge long-term serviceability and structural integrity (Mothe 2006).Continuous precast prestressed concrete bridges have therefore been adopted in practice in the United States to improve the bridge durability by eliminating bridge deck joints.However,concrete continuity diaphragm cracks over time due to concrete creep and shrinkage differential in the deck and girder (Mirmiran et al.