DEFLECTIONS OF REINFORCED CONCRETE ELEMENTS OF RECTANGULAR SECTION FROM THE LOADED LOAD

Abstract

Prediction of deflections in practice is complicated by the mathematical description of curvilinear dependencies that depict the dynamics of processes.

The work considers a simplified (linear) approach to the interpretation of the development of deflections in the conditions of different reinforcement of reinforced concrete elements based on the study of experimental tests of reinforced concrete beams [1]. The similarity of the hysteresis curves of deflections of reinforced concrete elements obtained by researchers (dependency of load - deflections) under different test conditions make it possible to implement a linearized model for simplification.

In this work, a linear approximation is proposed within the operating loads of 0.8 from the destructive one.

Setting the goal and objectives of the research:

1. With the help of mathematical methods [5], consider the possibility of describing the dependence "load - deflection" by linear approximations, in the areas preceding the critical loads Pw and Pu;
2. Finding the theoretical moment of crack formation

The following linear dependencies were obtained:

For the area before the formation of cracks -

For the area after the formation of cracks -

Conclusions.

1. The given results and their statistical processing confirm the reliability of the given mathematical apparatus for describing the deflections of rectilinear sections taking into account the change in the stiffness of reinforced concrete elements before and after the development of cracks.
2. This approach is simple and allows experimenters to analytically obtain compliance of deflections with applied loads within the limits of operational loads.
3. The presented linearized model makes it possible to check the correctness of the experiment.
4. The proposed possibility of analytical determination of the moment of crack formation in experimental beams.