Torsional Behavior of Solid and Hollow Core Self Compacting Concrete Beams Reinforced with Steel Fibers

Abstract

Torsion of structural members and the behavior of steel fiber self- compacting reinforced concrete became the area of interest for many researchers nowadays. The experimental program of the present work consists of casting nine reinforced self-compacting concrete beams in three groups. Each group consists of three beams with the dimensions of 200×300×1500 mm. The first beam has a solid cross-section, the second beam has a hollow core with the dimensions of 60×120×1500mm and the last beam has a hollow core with the dimensions of 80×180×1500mm. The steel fiber contents were 0, 0.5 and 1.0 % by volume for first, second and third groups respectively. The torsional angle of twist versus torsional moment (torque) of each beam was found during the experiments, and the effect of variables, fibers volume fraction and section geometry, on this relationship was investigated. Moreover, the fresh and hardened properties of concrete were carried out using several tests, which included slump flow, L-Box, compressive strength, tensile strength, and finally the torsion test. The current results showed that the addition of steel fibers has improved the torsional strength for all beams and the fibers were more effective in hollow core sections than in the solid ones.

Keywords

• self-compacting concrete
• steel fibers
• cracking torque
• ultimate torque
• twist angle
• hollow section