The present invention relates to a cold rolled steel beam comprising: a web having two layers of steel, the web having a top end and a bottom end; a pair of bottom flanges extending outwardly from the bottom end of the web; and a pair of top flanges extending outwardly from the top end of the web, each top flange having two layers of steel. Preferably, a portion of each bottom flange has two layers of steel, and the cold rolled steel beam includes a pair of end connectors extending generally orthogonally from the web and positioned generally orthogonally to the bottom flanges and the top flanges. Preferably, the cold rolled steel beam is cold formed from a unitary piece of sheet steel.

A structural reinforcement device for insertion into a cavity of a structure and method for making the same including a first reinforcement section that has at least one projection of a first expandable polymeric material secured to it; and a separate second reinforcement section mated with the first reinforcement section, the second reinforcement section being configured to include at least one cavity, into which the at least one projection penetrates upon mating, and at least one aperture defined therein through which the expandable material flows during expansion and where it will remain upon curing of the material, thereby causing the first reinforcement section to be coupled with the second reinforcement section.

A linear construction truss comprising a hollow shell with a square cross section and a core composed of linked tetrahedra, and a method of manufacturing of said linear construction truss comprising the steps of bending sheet metal strips to create a tetrahedral core such that the faces of the tetrahedral alternate between approximately 109.5 degrees and approximately 289.5 degrees throughout the length of the sheet metal strips. Strips of sheet metal are further bent to form a hollow shell with a square cross section rigidly attached to the core in a spiral pattern. The triangular faces are chamfered to better enable the connection between the core and hollow shell. The sheet metal is cut in such a way such that the perforations do not impinge on the edges of the tetrahedral.