Results of experimental studies of high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion

Abstract

The aim of the work - experimental investigation on crack propagation and deformation in high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion for the development of practical methods of crack resistance, deformation and strength analysis of such structures, and also for the accumulation of new experimental data on resistance under combined loading. Method is experimental-theoretical. Results. Deflection plots and force-deformation relationships for high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion are determined experimentally. Principal deformations in terms of elongation and compression of concrete for the experimental beam structures with high torsion to bending moment ratio are determined. It is established that for high-strength fiber reinforced concrete structures of circular cross-section, generally, development of one-two discrete cracks is observed, therefore the circular shape of the cross-section slightly reduces the concentration defined by the material structure of high-strength concrete. On the basis of the conducted investigation on high-strength fiber reinforced concrete structures with circular sections, new experimental data on the combined stress-strain state in the studied areas of resistance is obtained, such as: values of generalized cracking, and failure, load, its level relative to the ultimate load; distance between the cracks at different stages of crack propagation; crack widths at principal reinforcement axis level, at a double diameter distance from the principal rebar axes and also along the entire crack profile at various stages of loading; coordinates of nonplanar crack formations; patterns of crack formation, development and opening in reinforced concrete structures under combined bending and torsion.

Experimental Investigation of Compound Effect of Flexural and Torsion on Fiber-Reinforced Concrete Beams

“…Analytical and experimental investigations have been conducted in the literature to examine normal-strength concrete beams' combined bending and torsional strength [19]. Moreover, other researchers have focused on experimental studies of high-strength reinforced concrete structures under combined loading [20]. Leung and Schnobrich [19] discussed extending the diagonal compression field theory to study the post-cracking behavior of reinforced concrete sections subjected to combined axial force, biaxial bending, and torsion.…”

“…Onsongo [23] and Mardukhi [24] experimentally studied the compound effect of bending and torsion of normal-strength concrete beams. Travush et al [20] investigated crack propagation and deformation in high-strength steel fiber-reinforced concrete beams with round cross-sections under combined bending and torsion. However, minimal experimental data and no equations are currently available for the design of fiber-reinforced concrete beams utilizing synthetic or steel fibers subjected to combined bending and torsion loads.…”

Modeling and Simulation of Combined Bending-torsion Experiment Based on ABAQUS

“…Bending-torsional resistance is one of the hollow shaft's most important mechanical properties [3][4][5]. A combined bendingtorsion experiment was used to measure the bending-torsional resistance of a hollow shaft [6][7]. However, there are some problems in practice in the combined bending-torsion experiment.…”

The new hypothesis angular deformation and filling of diagrams in bending with torsion in reinforced concrete structures

“…The main task is to develop models that allow describing the behavior of structures at all stages of loading. Rectangular cross-sections are one of the most applicable, therefore the research of this type of cross-section is most important [10][11][12][13]. However, the complex stress state has not yet been sufficiently considered in scientific publications [14][15][16][17][18][19][20][21][22][23].…”