Title: Reinforcing Steel in Concrete and the Concept of Safety

Author(s): K. Hajnal-Konyi

Publication: Journal Proceedings

Volume: 48

Issue: 3

Appears on pages(s): 561-580

Keywords: no keywords

DOI: 10.14359/11940

Date: 3/1/1952

Abstract:
Comparative tests on 36 beams reinforced with various types of large size bars, both in ordinary and high grade concrete, prove the superiority of cold worked steel over steel having a natural yield point as regards safety factor and warning before failure. They also prove the advantage of deformed bars over plain bars regarding bond, crack formation and the necessity of increas-ing the strength of reinforcement, with improved bond, to avoid failure with-out warning. Two beams reinforced with 0.104-in. plain wires with a 268,800 psi tensile strength were also tested. Failure occurred by fracture of the reinforcement although the wires were not prestressed. Cracks were much narrower than with large size bars at comparable stresses. Strain measurements, within a very wide range of steel stresses at failure (42,500 to 294,200 psi), demonstrate good agreement with Whitney’s method of determining the position of the neutral axis.