Title:
Influence of Immersion Vibration on the Void System of Air-Entrained Concrete
Author(s):
M. J. Simon, R. B. Jenkins, and K. C. Hover
Publication:
Symposium Paper
Volume:
131
Issue:
Appears on pages(s):
99-126
Keywords:
air-entrained concretes; air entrainment; consolidation; freeze-thaw durability; fresh concrete; tests; vibration; voids; Materials Research
DOI:
10.14359/1203
Date:
3/1/1992
Abstract:
Experiments were conducted to determine the influence of immersion vibration on the air-void system parameters of air-entrained concrete, as a function of both radial distance and depth from the point of vibrator insertion. For a 1½ in. (40 mm) diameter immersion vibrator, one could conclude that vibration has little or no effect on air-void systems at distances of 5, 8, or 10 in. (125, 200, or 250 mm) from the point of insertion. The same vibrator in the same concrete can reduce the total air content by 50 percent, and increase specific surface by as much as 100 percent directly at the point of vibrator insertion. Which particular effect one may observe in hardened concrete, therefore, depends on the selection of core location relative to point of vibrator insertion. These observations have implications for specifying, casting, and testing air-entrained concrete.