Title: Evaluating Historical Flexural Members Reinforced with Ransome Bars

Author(s): Umesh Poudyal and Lisa R. Feldman

Publication: Structural Journal

Volume: 115

Issue: 5

Appears on pages(s): 1443-1451

Keywords: bar size; casting position; development length; historical structures; lap splice; Ransome bars; square twisted reinforcement; structural evaluation

DOI: 10.14359/51702251

Date: 9/1/2018

Abstract:
Ransome bars were used to reinforce concrete structures until approximately the mid-1950s in the United States and Canada. However, historical editions of the ACI code do not clearly state whether provisions for average bond stress for typical deformed bars apply equally to Ransome bars. An experimental investigation of splice specimens reinforced with cold-twisted Ransome bars was therefore conducted. The required splice length of these bars was established and compared to that calculated for modern deformed bars using provisions in ACI 318-14 and shows that a multiplier of 1.25 for Ransome bars appears reasonable provided that a top cast factor that better represents these bars is also incorporated. The flexural resistance of members reinforced with Ransome bars must also take into account the sudden nature of the anticipated failure.