A system and method for reinforcing at least a portion of a structural member, including at least one hollow carrier, having an exterior shell and an interior portion, which substantially conforms to the dimensions and geometry of the structural member being reinforced; and a lightweight, low density material for filling the interior portion of one or more of the carriers. The material filling one or more of the carriers of the present invention can be a reinforcement material, self-curing material, or a heat activated expandable material. The carrier can be produced by blow molding or rotational molding and has an adhesive material disposed along at least a portion of the exterior shell used to place, adhere, and affix the carrier to a targeted portion of the structural member selected to be structurally reinforced.