On the Composite Prestressed Concrete-Steel Structural Module : 1st Report : Stress and Deformation During Prestressing

Abstract

It was confirmed through preliminary studies that composite concrete-steel structures are best fitted for the strength members of huge offshore structures, due to the high strength and ductility, and good weldability of steel and due to the low ratio of cost to the weight and excellent durability of concrete. A new prestressed concrete-steel structural module hase been developed for the strength members of offshore structures. The composite structural module is composed of biaxially prestressed concrete and a steel frame surrounding the concrete. The prefabricated composite structural modules are joined together to bild the main structure by welding the steel frames. The joint between composite modules is simpler and more reliable than those of conventional concrete structures. In the paper, the authors carried out both experimental and theoreticai investigations into the stresses and deformation of the composite modules during prestressing. Experiments were carried out by fabricating a prototype composite module ; a full scale model, and a floating break water. Theoretical analyses were carried out on stress distribution and bending deformation during prestressing. A comparison of calculated and observed results shows good agreement. Based on this comparison, the fundamental properties of the composite were clarified.