Abstract: A rectangular shaped interlocking building block comprises a pair of exterior sides and an upper and a lower longitudinally extending horizontal faces and a pair of opposite vertical ends and wherein said building blocks include a pair of side members and wherein each of said side members includes a vertically extending exterior rib on an inner side thereof; a generally rectangular intermediate section is disposed between said side members in an abutting relationship and wherein the intermediate section defines a rectangular shaped vertical recess between the side members and a recess that extends between a bottom of one of said side members and the top of an adjacent block. The rectangular rib and vertical recesses are constructed and dimensioned so that one rib fits loosely but closely within the recess and the intermediate section includes a pair of elliptical shaped vertical passageways.

Abstract: A rectangular shaped interlocking building block comprises a pair of exterior sides and an upper and a lower longitudinally extending horizontal faces and a pair of opposite vertical ends and wherein said building blocks include a pair of side members and wherein each of said side members includes a vertically extending exterior rib on an inner side thereof; a generally rectangular intermediate section is disposed between said side members in an abutting relationship and wherein the intermediate section defines a rectangular shaped vertical recess between the side members and a recess that extends between a bottom of one of said side members and the top of an adjacent block. The rectangular rib and vertical recesses are constructed and dimensioned so that one rib fits loosely but closely within the recess and the intermediate section includes a pair of elliptical shaped vertical passageways.

Abstract: A concrete filled tubular steel column includes a longitudinally extending vertical tubular steel shell and an inner tubular steel member disposed at the center of the steel shell. A plurality of spaced vertical steel plates extend from the inner members toward but not abutting the steel shell. In addition a plurality of horizontally disposed perforated pipes extend outwardly from the inner member and have a plurality of meltable polymer plugs or caps to prevent plastic cement from flowing into or closing the openings. In the event of fire the plastic or polymer plugs or caps melt and allow gases and smoke to flow into the pipes and up through the inner member and out therefrom at the top of the column.