Title: Effect of Controlled Vibration Dynamics on Concrete Mixtures
Author(s): Yifeng Ling and Peter Taylor
Publication: Materials Journal
Appears on pages(s): 161-172
Keywords: air movement; concrete internal vibration; controlled frequency vibrator; material separation; vibration energy; water movement
Although internal vibration has been widely implemented in concrete pavements, reports about concrete deterioration caused by improper vibration have been emerging. This study investigates the transmission of vibration energy, water movement, and air movement in concrete under vibration to provide the experimental basis for a better understanding of vibration in different concrete mixtures. An innovative experimental method was developed to measure energy transmission in concrete. The mixtures varied by air content, slump, and water-reducing admixture addition and were prepared to test the vibration energy, water absorption, and the air-void system for a range of vibrator frequencies. The vibration energy transferred through the mixture generally displayed a linear rise, then a slight drop, and, finally, stability, indicated by both measurements of transferred energy and voltage demand of the vibrator. The magnitude of vibration energy transferred through the mixtures increased with an increasing slump. For all samples tested, water appeared to move away from the vibrator, most markedly with an increasing frequency. There is a clear indication of air movement to the surface of the concrete in all tested samples.