Criteria for Heat Curving Steel Beams and Girders

Information obtained in an investigation of the effects of heat curving, and the results of a subsequent analysis of the bending behavior of heat-curved members, have been used to formulate criteria for heat curving rolled beams and welded girders. Two of the main provisions of the criteria are the requirements for: (1) A minimum radius; and (2) an increase in the usual vertical camber. The minimum-radius requirement was selected to prevent excessive web bowing due to the combined effects of the residual compressive stresses and shear stresses from applied loads. The requirement for increase in camber was selected to negate vertical residual deflections, or loss in camber, as a result of slight inelastic action under initial loading. A specification for heat curving, essentially in accordance with the criteria analyzed in this paper, was recently (1969) adopted by AASHO.