Static and fatigue tests have been conducted on Bi-Steel steel-concrete-steel sandwich beams. A truss mo with tapering web compression members is proposed for calculating the forces within the beams. The model gi conservative predictions of the failure loads and modes of the beams. A deflection equation has been developed taking account the slip between steel plates and concrete, giving good agreement with measured values. A fatigue life calcula method has been proposed which takes into account interaction of the applied forces at bar-plate connections and gi conservative predictions of fatigue life.