Abstract: Elongate, composite-material, hollow rebar structure, along with associated components, related fabrication apparatus, and apparatus-implemented, rebar-structure-making methodology. The rebar structure has a long axis, and includes (a) an elongate, hollow core centered on that long axis, (b) an elongate, hollow sleeve having inner and outer surfaces, circumsurrounding the core along the core's length, with the sleeve's inner surface bonded to the core's outer surface along the length thereof, and (c) longitudinally distributed, radial-dimensionality, external-purchase-enhancing structure formed unitarily with the sleeve's outer surface along the length thereof. The bond existing between the core and the sleeve takes the form of a single-cure, reverse-temperature-gradient-cure, plastic-material, molecular bond.