The vibration rheometer: the effect of vibration on fresh concrete and similar materials

Abstract

The use of the newly-designed electronic accelerometer as an integral part of the vibration rheometer, for the first time made it possible to continuously and accurately record the acceleration of an apparatus piston as a solid mass oscillating in the test specimen of the material under sub-base excitation. The research is focused on plastic concrete, mortar and appropriate reference materials whose behavior was approximated to a pseudoplastic fluid. An analytical solution to the oscillation of the piston in the specimen is also provided. The research showed that a layer of the material with the properties close to the ideal Newtonian fluid forms around each particle exceeding 0.25 mm causing a reduction in resistance to deformation and compression in a specimen. The effect of vibrations on plastic concrete and similar materials is also described.

The extension of thixotropy of cement paste under vibration: a shear-vibration equivalent theory

“…On the other hand, many researches have showed that the rheological properties of concrete change under vibration [9][10][11][12]. Tattersall used a vertical tube method to study fresh concrete under vibration.…”

“…However, for a sinusoidal vibration process, it is difficult to calculate its vibration intensity directly, so a new parameterv ib is introduced to describe the vibration intensity. On the other hand, when the direction of vibration is perpendicular to the direction of rotation of the rotor, as is illustrated in Figure 2, formula 7and formula (8) are simplified as formula (10).…”