Relationship between the rheology of unvibrated fresh concrete and its flow under vibration in a vertical pipe apparatus

Ten different concretes have been tested under vibration using a vertical pipe apparatus. The fluidity of the vibrated concrete, determined from the rate of efflux from the pipe, is controlled by the peak velocity of the vibration and influenced by the rheology of the unvibrated concrete. Fluidity is proportional to peak vibrational velocity up to a critical level, above which it increases no further. The critical velocity is proportional to the yield value of the unvibrated concrete, and the peak fluidity is inversely proportional to the plastic viscosity of the unvibrated concrete.