Title: Bond of Plain Bars in Early-Age Concrete under Bilateral Pressures

Author(s): Wen-Ming Li, Zhi-Min Wu, Jian-Jun Zheng, and Rena C. Yu

Publication: Structural Journal

Volume: 120

Issue: 3

Appears on pages(s): 61-74

Keywords: bilateral pressure; bond behavior; early-age concrete; plain steel bar; pullout failure

DOI: 10.14359/51738665

Date: 5/1/2023

Abstract:
Plain steel bars are still used in reinforced concrete structures in some developing areas or in some special structural joints for greater ductility. The purpose of this paper is to present an experimental study on 432 pullout specimens to quantify the effects of level of bilateral pressures and curing age on the bond behavior of plain steel bars in early-age concrete. Based on the experimental results, the time dependence of the peak bond stress and the slip at peak bond stress is analyzed. Two empirical formulas are formulated for evaluating the peak bond stress and the slip at peak bond stress in terms of the strength of concrete, the curing age, and the level of lateral pressures. Finally, an empirical bond stress-slip relationship is proposed and verified by experimental results.