System for improving fire endurance of concrete-filled steel tubular columns

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.