Bond characteristic experiments of reinforcing bars corroded before and after concrete casting

Title: Bond characteristic experiments of reinforcing bars corroded before and after concrete casting
Author(s): L. Chung, J.-H. Jay Kim
Paper category : conference
Book title: International Conference on Advances in Concrete and Structures
Editor(s): Ying-shu Yuan, Surendra P. Shah and Heng-lin Lü
Print-ISBN: 2-912143-41-1
e-ISBN: 2351580176
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 321 - 337
Total Pages: 17
Nb references: 6
Language: English

Abstract: 
Due to the shortage of natural fine aggregates, sea sand has been alternatively used for casting of concrete. However, due to the presence of sodium in sea sand, the threat of corrosion in reinforcing steels embedded in concrete made from sea sand has been a major concern recently. Also, reinforcements used for many RC structures are exposed to moisture in the air causing slight corrosion even before casting of concrete. In order to qualitatively and quantitatively understand the effect of corrosion on the bond strength and length in RC members, two types of testes are planned. First specimen is cubic concrete specimens made for pullout test which has its reinforcing bar pre-corroded before casting. The reinforcing bar of the second specimen is corroded after concrete casting. Two types of reinforcing bars D13 and D19 are pre- and post-corroded to 2, 3, 4, 5, 7, 10% of its original cross sectional area of the reinforcement using current-induced accelerated corrosion technique. After the effective corrosion is applied, pullout tests are performed on both types of specimens. The experimental results showed that the pre- and post-corroded specimens failed in ductile and brittle manner, respectively. Also, the pre-corroded concrete specimens with D13 and D19 reinforcing bars maintained their bond strength up to corrosion of 3 and 8%, respectively. However, the post-corroded specimens maintained their bond strength only up to corrosion of 1% for both D13 and D19 bars. The difference in the behavior of these two RC members is due to the recovery of bonding between concrete and steel bar during casting and hardening for pre-corroded specimens and the formation of expansion stress leading to concrete cracking for post-corroded specimens.

Online publication: 2003-08-10
Publication type : full_text
Public price (Euros): 0.00