Title:
Bond of Reinforcement to Revibrated Concrete
Author(s):
Wilsam A. K. Altowaiji, David Darwin, and Rex C. Donahey
Publication:
Journal Proceedings
Volume:
83
Issue:
6
Appears on pages(s):
1035-1042
Keywords:
bond (concrete to reinforcement); concrete construction; consolidation; cover; reinforced concrete; reinforcing steels; revibration; vibration; workability.
DOI:
10.14359/1903
Date:
11/1/1986
Abstract:
The effects of revibration on concrete-steel bond strength are studied. Key variables are concrete slump, bar position, and the time interval between initial vibration and revibration. No. 8 (25 mm) deformed reinforcing bars were used with a 2 in. (51 mm) cover and a 10 in. (254 mm) bonded length. Concrete slumps ranged from 2 3/4 in. to 7 « in. (70 to 190 mm). Two specimen depths were used. All specimens were modified cantilever beam specimens. The experimental results show that revibration is not universally beneficial to concrete-steel bond. Revibration appears to improve bond strength for top-cast bars placed in high-slump concrete. Revibration may, however, severely damage bond strength for bars cast in well-consolidated, low-slump concrete. Revibration is almost universally detrimental to the bond strength of bottom-cast bars. Overall, revibration tends to reduce the differences in bond strength caused by differences in slump and bar position.