In order to overcome the shortcomings of precast composite beams

such as easy cracking in post-cast zone

poor ductility

and easy to damage

engineering cementitious composites (ECC) were used in the precast plate and post-cast area of composite beams. Bending tests were carried out on 11 beam specimens. The flexural properties and effects of the ECC plate thickness

connecting method of reinforcement

and reinforcement ratio on the flexural properties were investigated. Bearing capacity and displacement of its characteristic point were studied. The crack width was measured and the laws of crack development trend and damage evolution were analyzed. The results show that the load

displacement

and ductility of the precast beams with ECC plate and post-cast joints under cracking

yielding

and ultimate condition were higher than those of RC beams. The thicker the ECC plate was

the more significant the effect was. The reinforcement connection methods of steel sleeve and hoop-inserting could effectively transfer the reinforcement stress. The precast beam could effectively control the crack width in bending area

and the damage index was larger when it was damaged. However

it could still bear load when the damage was serious

which is suitable for the key joint of precast structure.