A method and analysis of the internal stress-strain state of the bent composite section are presented.  The methods of self-stressing of steel-concrete construction elements are given. The method of self-stressing of the steel-concrete bending elements, which was not previously known, through the use of shrinkage forces of concrete in composite structures is given. The results of the numerical investigation of self-stressing and prestressing steel-concrete beams using computer programs are described. The prestressing forces were transmitted to the end stops due to the steel rigid ribs of the composite structure. Prototypes were made for the full-scale test and tested based on the results of numerical studies. The results of full-scale tests are presented and comparisons with the results of numerical studies are given.