A corrosion resistant concrete reinforcing member includes (i) an elongate core member defining a longitudinal axis; (ii) a longitudinally extending outer wall connected to and extending around the elongate core; and (iii) a void between the elongate core and the outer wall that is in fluid communication with the outside of the reinforcement member; wherein the surface area defined by the portions of the elongate core and the outer wall that define the void is adapted to contact concrete and assist in mechanical bonding of the reinforcing member to the concrete.