Effect of shear span to depth ratio on the statical behavior of HSCB subjected to transverse loading

الملخص EN

Many researches were carried out to investigate the properties and structural performance of high strength concrete for many decades.

While these researches have produced relevant and useful results, there are several properties of high strength concrete like compressive and tensile strengths, stiffness, durability, modulus of rupture, cracking shear load and ultimate load that need to investigate to determine an accurate evaluation of beams made of high strength concrete.

This study investigates the effect of shear span-depth ratio (a/d) on the statical behavior of HSCB subjected to transverse loading.

The effect of shear span to depth ratio includes some main mutual factors such as grade of concrete and stirrups spacing.

The studied statical behavior includes: evaluation of pattern of cracks, modes of failure, concrete and steel strains, maximum deflection, flexural cracking load (Pcr), modulus of rupture, cracking shear load (Vcr) and finally ultimate load (Pu).

For this purpose, an experimental test program was performed which included testing twenty four large scale simply supported rectangular high strength concrete beams under one concentrated transverse load at mid span.

The values of the main factors were; the shear span to depth ratio (a/d) were taken (3, 2, 1.5 and 1), the cube compressive strength (fcu) were (575, 766 and 890) kg/cm2 and the stirrups spacing were (20, 14.28, 11.11and without stirrups) cm, while the longitudinal reinforcement was kept constant for all tested beams.

For all tested beams, max.

Deflections, strains in the longitudinal reinforcement, and strains in concrete were measured and recorded.

Also, the initiation and propagation of cracks were recorded.

Cracking patterns and failure modes were observed.

Cracking and failure loads were recorded.

The test results were compared with different codes and formulas.

Based on this, conclusions were drawn out for induced measured maximum deflection, steel and concrete strain, the cracking load the modulus of rupture, shear cracking load and ultimate load for beams with and without stirrups.

In addition, ultimate shear load for beams without stirrups utilizing different code provisions was predicted and compared with the obtained test results.