An injection plug device for injecting concrete repairing agent into a concrete structure and a connector

An injection plug device for injecting concrete repairing agent into a concrete structure and a connector to be connected to such an injection plug device are provided. The injection plug device has a small diameter, a simple structure, and low manufacturing cost to be appropriate to be used as a disposable device. The injection plug device (10) for injecting concrete repairing agent into a concrete structure includes a tip side injection pipe (11); an end side injection pipe (12) for housing an end portion of said tip side injection pipe (11) at the tip portion thereof, an attaching means (13) consisting of an elastic member(l3a) attached to said tip side injection pipe(11) to surround the outer surface thereof, and a compression means for compressing said elastic member(13a) in a direction parallel to an axis thereof to cause an expansion of said elastic member(13a) in its radial direction to make said elastic member attached pressurizingly to a inner wall of an injection hole; and a back flow preventing means (14) formed inside of said end side injection pipe for preventing back flow of injected concrete repairing agent before its solidification.