THE RESULTS OF EXPERIMENTAL STUDIES OF STRUCTURES SQUARE AND BOX SECTIONS IN TORSION WITH BENDING

In result of experimental research the plots of the deflections and rotation angles, the dependency of deformations of concrete according to the testimony of the outlets of electrodesorption with respect to the calculated cross sections 1-1. The main deformations of elongation and shortening of concrete were determined; the reinforcement was selected in such a way that in the stage preceding the destruction, it reached fluidity, so the stresses in the reinforcement are known. It is established that for reinforced concrete structures made of high-strength concrete of square cross-section during torsion with bending, as a rule, there is only one main crack (the fragilestructure of high-strength concrete contributes to such a concentration), along which the destruction occurs. For the box section there were several cracks, of which stands out the one on which the destruction occurs. On the steps preceding the destruction, this crack begins to prevail over the rest and has s maximum opening width. On the basis of experimental studies of reinforced concrete structures made of high-strength concrete of square and box sections, reliable data on the complex stress-strain state in the studied areas of resistance, such as: the values of the generalized load of cracking and destruction ; its level relative to the limit load; the distance between the cracks at different levels of cracking (up to the moment of destruction, as a rule, two or three levels are formed); crack’s width at the level of the axis of the working rebar, at a distance of two diameters from the axes of the rebar and along the entire crack profile at various stages of loading, from which it follows that the crack opening at the level of the axis of reinforcement in 2 - 3 times less compared width the crack opening on the removal of 1.5 - 2 diameters of the working axis (longitudinal and transverse) reinforcement; the coordinates of the points (x; y; z) the spatial formation of cracks; schematic sketchers for tablets occurrence, development and opening of cracks of reinforced concrete constructions in torsion with bending. Thus, the experimental studies and the result provide an opportunity to test the developed computational model and its working hypotheses for assessing the resistance of reinforced concrete structures made of high-strength concrete in torsion with bending.

reinforced concrete structures, high-strength concrete, torsion with bending, experimental results, cracks’ opening

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