Title:
Effect of Consolidation on Bond of Reinforcement in Concrete of Different Workabilities
Author(s):
Yin-Wen Chan, Yong-Guo Chen, and Yi-Shi Liu
Publication:
Materials Journal
Volume:
100
Issue:
4
Appears on pages(s):
294-301
Keywords:
consolidation; high-performance concrete; strength; vibration; workability.
DOI:
10.14359/12667
Date:
7/1/2003
Abstract:
The effect of consolidation on concrete-steel bond strength was investigated. Key variables included the degree of consolidation and concrete workability. D32 (No. 10) deformed reinforcing bars were used with a 250 mm embedment length. Three different types of concrete were adopted: normal concrete with low slump (75 mm), high-performance concrete with high slump (220 mm), and self-compacting concrete (SCC). Reinforcing bar pullout tests were conducted to measure the bond strength of reinforcing bars in concrete subjected to various consolidation conditions. Different consolidation conditions were adopted to simulate various situations that might occur during practical concrete placement, including standard vibration, overvibration, no vibration, and improper vibration. The experimental results indicate that consolidation is absolutely important to the bond strength development of reinforcing bars in normal concrete. The bond strength of normal concrete is significantly reduced when no vibration is applied. The application of vibration in high-performance concrete (HPC) is so crucial that overvibration or improper vibration would result in a substantial reduction in bond strength. Without any consolidation, SCC is capable of developing a remarkably higher bond strength than the control case. Furthermore, the application of vibration in SCC may affect the bond strength and should be prevented.