BASIS OF OPTIMISING STRENGTH THEORY OF REINFORCED CONCRETE BAR ELEMENTS AND CONSTRUCTIONS

The general Optimizing Strength Theory of Concrete Elements (OSTCE) of the normal and inclined sections (cracks) under co-action of the bending moments M, shear Q and longitudinal N forces is suggested. The OSTCE uses, generalizes and develops the known principles of the strength designs of the RC elements: design on the failure stage, entire use of reinforcement strength and connected with this the plastic failure, ultimate equilibrium method for the redundant structures. So, the OSTCE guarantees the plastic failure not only of normal sections but inclined ones under shear forces action. The OSTCE overcomes the important disadvantages of the known strength design methods, in particular, absence of system unity of all known elements strength designs and non-deriveness of the partial design cases from the general ones that testified about of principle imperfection of these designs and about corresponding non-optimality of structures projected by such designs. The great role of extreme strength criteria in the OSTCE caused its name “Optimizing”. The central place of the OSTCE is occupied by the general strength design case of the inclined section under co-action M, Q, N forces from which there are derived the partial strength design cases of the inclined and normal sections under co-action of M and Q and also designs of the normal section under co-action M and N and one M or N. In the OSTCE the improved design of the normal section is worked out for two levels of accuracy and simplicity which are stipulated by the assumed stress distribution on the height of compressed concrete zone: 1) uniform; 2) curve according to the entire compression diagram of concrete. The mastering of the OSTCE signifies the acquisition of knowledge of at once all the most meeting in practice the strength designs of the RC elements.

• ABSTRACT

• INTRODUCTION

• BASIC ASSUMPTIONS

• BASIC RELATIONSHIPS

• FORMULATION AND SOLUTION OF THE BASIC PROBLEMS

• IMPROVEMENT OF THE ULTIMATE EQUILIBRIUM METHOD

• EXPERIMENTAL VERIFICATION OF THE OSTCE

• CONCLUSIONS

• REFERENCES