Designing of Standard Cross Sections of Composite Bending Reinforced Concrete Elements by the Method of Design Resistance of Reinforced Concrete

The principles of designing standard cross sections of composite bending reinforced concrete elements using modern deformation models have been considered in the proposed article. This paper is dedicated to composite beams with symmetrical cross sections, which are most frequently used in practical activity in construction sphere. In such elements there are neither torsion, nor tension in perpendicular plane of effect of forces, thanks to which they have the highest loading-carrying ability as compared to asymmetrical composite constructions. The authors have developed an alternative calculation method for the composite bending elements by using the method of analysis of design resistance of reinforced concrete. The given method makes it quite easy to make calculations of such elements, concurrently its precision corresponds to the accuracy of calculation of modern deformation models, taking into account nonlinear deformation curves of materials. The procedure for calculating three types of problems, which are typically used in construction practice, has been proposed in this research work. This article presents the procedure of calculation of the following problems: determination of the required area of reinforcing steel according to the known size dimensions of composite beams and defined strength grade of materials; determination of the bearing capacity of standard cross sections with known reinforcement; checking procedure of the bearing capacity of composite bending elements. An example of calculation of standard cross sections of composite bending reinforced concrete elements made of different concrete grades.