Rheological behaviors and model of fresh concrete in vibrated state

Abstract The rheological behavior of fresh concrete under vibration is very different from that in static state. In this study, the relationship between shear strain rate and shear stress of fresh concrete under vibration was theoretically analyzed based on Eyring rate process theory and vibration damping theory, and the constitutive equations were gotten. At low shear strain rates, vibrated fresh concrete is a Bingham liquid, even Newtonian when vibrating time is enough long. However, at high shear strain rates, the shear stress - shear strain rate relationship is a logarithmic function. The shear deformation resistance decreases with increasing vibrating time, but increases with the distance from vibrator or the thickness of concrete. The rheological measurement in vibrated state was also conducted by using a ring shear type rheometer, into which a rod vibrator is integrated. The experimental results of shear stress - shear strain rate relationship were well consistent with the theoretical equations.