Experimental Study on Optimal Re-vibration Compaction of Concrete

Abstract

One of the construction methods to improve the quality of concrete is re-vibration that gives vibration again after a certain time after initial vibration compaction. However, there is very little information on the specific implementation timing and method of re-vibration, and the actual situation is that re-vibration is performed based on sense and experience of the workers at the site. In this study, the concrete resistance value obtained from the N-type penetration depth was used as an index of the timing of re-vibration, and the effects of re-vibration timing and duration were examined. As a result, it was found that re-vibration was most effective when the concrete resistance value reached 17 × 10^-3N / mm². In addition, when the re-vibration duration was 5 to 10 seconds, the quality of the concrete was most improved. On the other hand, if the re-vibration timing was late or the re-vibration duration was long, improvement of concrete quality due to re-vibration could not be expected.