Title:
ACCEPTABLE VIBRATIONS ON GREEN CONCRETE
Author(s):
Seamus F. Freyne, Mitchell L. Watkins, and Adam Browne
Publication:
Materials Journal
Volume:
112
Issue:
3
Appears on pages(s):
471-476
Keywords:
coarse aggregate; compressive strength; early age; foundation; green concrete; vibration.
DOI:
10.14359/51687393
Date:
5/1/2012
Abstract:
Vibrations are potentially harmful to green concrete in shaft foundations, and many states, including Mississippi, cautiously established limits in terms of compressive strength, distance boundary, and wait time to protect early-age concrete. These limits, however, could be overly conservative with respect to experimental evidence, and perhaps unnecessarily impede construction schedules and add to project cost. The objective of this study was to quantify the effects of early-age vibrations on concrete performance. Concrete cylinders were exposed to several combinations of vibration magnitudes and durations that were representative of shaft construction, and at ages coincident with the sensitive period between initial and
final set. The vibrations had no consistent influence on compressive strength and electrical resistivity. There was also no discernable difference between limestone and river gravel coarse aggregates.