Experimental study and theoretical prediction on torsional strength with different steel fiber reinforced concretes and Cross-Section areas

Abstract

Steel fiber reinforced concrete (SFRC) has obtained attention from researchers and engineers to be employed in various structural applications to improve concrete structures' performance. However, there are limited experimental test results on the impact of the beam cross-section area along with fiber dosage and configuration on the torsional behavior of the SFRC beams. The aim of this study is to examine the effect of beam section sizes on the characteristics of the torsional performance of cracking and ultimate torsional strengths of SFRC beams. Fiber contents of 0.0, 0.5, 1.0, and 1.5 % with two different lengths of steel fiber were mixed with concrete to study fiber lengths and dosage influences on the torsional behavior. Moreover, torsional loads and cracking and ultimate torque equations of SFRC beams with different fiber dosages and lengths were proposed. Results showed that the SFRC beams exhibited higher cracking torsional moment than the control beams. The hooked steel fiber reinforced beam exhibited the highest increase of the total torsional toughness with the large area and 1.5% fiber dosage, while the straight micro steel fiber beams show good performance with a 1.5% fiber dosage with a small cross-section area. The results from past research and the proposed equations of the cracking and ultimate torques exhibited a good correlation.