A blade segment for a wind turbine rotor blade may generally include a body shell terminating at a joint end. The body shell may include a pressure side and a suction side extending between a leading edge and a trailing edge. The blade segment may also include a plurality of pressure side tubes extending adjacent to the pressure side of the body shell and a plurality of suction side tubes extending adjacent to the suction side of the body shell, with the plurality of pressure side tubes being spaced apart from the plurality of suction side tubes along a flapwise direction of the rotor blade.