To calculation of steel-reinforced concrete ribbed plates for refurbished floors

Abstract

Analyzes national experience of restoring the old buildings floors. An assessment of the wood-reinforced concrete using experience, steel-reinforced concrete floor structures and methods for calculating load-bearing elements of a composite section is given. It is noted that the current design standards and existing methods for calculating steel-reinforced concrete structures of civil buildings and bridge structures use simplified calculation methods and do not reflect the actual stress-strain state of a bent element, do not take into account the initial pre-operational deformations and stresses, and do not lead to economical design solutions. Sometimes they lead to incorrect results. Expressions of internal moments and forces of steel-reinforced concrete bending elements are presented from the equilibrium conditions of a composite element, taking into account pre-operational forces. The results of our own experiments are presented, where it is shown that during the hardening of concrete, beams and slabs receive deformations in the form of reverse deflection (bending), and internal stresses arise in the sections of steel-reinforced concrete elements. Formulas are given for calculating the deflections of bending elements taking into account their initial deformations.

To compare the calculation results of the proposed method for calculating steel-reinforced concrete elements, taking into account the initial deformations and stresses, the data of our own experiments were used and comparisons were given. Satisfactory convergence of the results is shown.