Rheology and vibration of fresh concrete: Predicting the radius of action of poker vibrators from wave propagation
The compaction of fresh concrete by an internal poker vibrator has been analysed using closed-form solutions for the propagation of the shear and compressive waveforms, assuming that concrete conforms to the Bingham model. In the inner liquefied zone around the vibrator the flow is due to shear wher...
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Published in | Cement and concrete research Vol. 41; no. 9; pp. 932 - 941 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier Ltd
01.09.2011
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The compaction of fresh concrete by an internal poker vibrator has been analysed using closed-form solutions for the propagation of the shear and compressive waveforms, assuming that concrete conforms to the Bingham model. In the inner liquefied zone around the vibrator the flow is due to shear whereas in the outer unsheared zone propagation is due to compressive waves. The analysis gives a method of predicting the radial position at which the flow changes, which coincides with the radius of action of the vibrator. Theory and experiment agree well and confirm that the peak velocity of the vibration governs its efficacy, with radius of action increasing with increasing velocity. The radius of action increases with decreasing yield stress and with increasing plastic viscosity. The work offers the potential to optimise the design and use of vibrators. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0008-8846 1873-3948 |
DOI: | 10.1016/j.cemconres.2011.04.011 |