Effects of Bending and Re-bending on Mechanical Properties of Locally-Manufactured Steel Rebars

Patrick W. Waruhiu, Department of Mechanical and Automotive Engineering, Technical University of Mombasa, P.O. Box 90420-80100, Mombasa, KenyaFollow
Simon I. Marandu, Department of Mechanical and Industrial Engineering, University of Dar es Salaam, P.O. Box 35131, Dar es Salaam, TanzaniaFollow
Mussa I. Mgwatu, Department of Mechanical and Industrial Engineering, University of Dar es Salaam, P.O. Box 35131, Dar es Salaam, TanzaniaFollow

Section

Physical Sciences

Abstract

Steel rebars experience deformation when subjected to bending and re-bending operations. Subsequently, their microstructures are impaired thus affecting the mechanical properties and leading to failure. This study establishes the effects of bending and re-bending the steel rebars on the mechanical properties. Experiments were conducted to determine the effects of bending and re-bending of the steel rebars. Testing was conducted on Ten virgin and Thirty specimens which were bent and re-bent at 45º, 90º, and 180º, and followed by tensile tests. Yield strength, ultimate tensile strength, elongation, and ultimate tensile strength to yield strength ratio (Rm/Re), were recorded. Results showed the yield strength, ultimate tensile strength, elongation, and Rm/Re of virgin steel rebars varied from 553.62 MPa to 618.49 MPa, 634.39 MPa to 745.68 MPa, 17.6 % to 21.67 %, and 1.14 to 1.19. The yield strength, ultimate tensile strength, elongation, and Rm / Re of bent and re-bent steel rebars at angles of 45º, 90º, and 180º varied from 603.67 MPa to 677.38 MPa, 692.82 MPa to 751.76 MPa, 6.88 % to 19 % and 1.09 to 1.21. It was established that bending and re-bending increase strength and reduce the ductility of the rebars proportionally.

Recommended Citation

Waruhiu, Patrick W.; Marandu, Simon I.; and Mgwatu, Mussa I. (2024) "Effects of Bending and Re-bending on Mechanical Properties of Locally-Manufactured Steel Rebars," Tanzania Journal of Science: Vol. 50: Iss. 1, Article 2.
Available at:https://doi.org/10.4314/tjs.v50i1.5