DETERMINATION OF NORMAL SECTIONS STRENGTH OF CONTINUOUS BENDING REINFORCED CONCRETE ELEMENTS SUBJECTED TO STATIC REPEATED AND ALTERNATING LOADS

Abstract

The article presents an improved methodology for determining the stress-strain state and strength of normal sections of continuous reinforced concrete beams and their bearing capacity according to current regulations, taking into account changes in the concrete mechanical characteristics under the action of repeated and alternating loads. The theoretical solutions are in satisfactory agreement with the experimental data.

On the basis of experimental and theoretical studies, the authors have proposed an improvement of the strength determining methodology of normal sections of bending reinforced concrete elements, including statically undefined, subjected to repeated and alternating loads. The methodology for  normal sections strength determining of bending elements, set out in the current regulatory documents, does not take into account the peculiarities of changes in the stress-strain state and strength of sections under the above loads.  And these changes are significant, especially at high levels, as shown by experimental results when testing prototypes of static and continuous beams. These changes occur due to changes in the physical and mechanical properties of concrete, deformation and its elastic modulus. Using mathematical operations, the equations for determining the forces in the normal section of bending reinforced concrete elements are established.