The present invention provides a process for repairing concrete involving filling one of a void, gap or seam in the concrete with a polyurethane sealant containing a silane terminated prepolymer ('STP'), and a catalyst, optionally, one or more of plasticizers, fillers, pigments, drying agents, light stabilizers, antioxidants, thixotropic agents and bonding agents and applying an isocyanate-terminated prepolymer containing polyurethane or polyurea coating to the silane terminated prepolymer polyurethane sealant.