creating a zero-thickness layer using ABAQUS 6.13

i have concrete slab and cfrp sheet i want to strength that slab with cfrp sheet so i try to model the epoxy layer as a cohesive layer between them the issue is when creating the orphan meshing which can be done by mesheing all instances as a normal mesh then selecting the slab and cfrp and go to mesh/creat mesh part after that go to mesh/edit and then selecting mesh/offset(creat solid layers) and now abaqus requires to select the element faces from which the offset will be generated so i selected the cfrp surafce that must be sticked to the slab by epoxy and then i create the set and assigened the section and material of cohesive to that set 

my problem is when i run the program the slab begin to deflect but that cfrp and the eopxy remain at its original position !! never deflect its like its not assigned to the slab !!

please help me how to creat that zero-thickness layer ??