A segment is coupled to another segment in circumferential and
longitudinal directions thereof to assemble a rehabilitating pipe for
rehabilitating the existing pipe. Each of the coupled segments has at
least one coupling surface provided with a recessed part that confronts
the recessed part at the coupling surface of the segment to which it is
coupled to form therebetween a gap that is configured to receive and hold
waste material existing at a bottom surface of the existing pipe when the
rehabilitating pipe is assembled inside of the existing pipe.