THE COMPACTION OF CONCRETE BY INTERNAL VIBRATORS - AN INVESTIGATION OF THE EFFECTS OF FREQUENCY AND AMPLITUDE
The influence of the frequency and amplitude of an internal vibrator upon its effectiveness has been studied in a programme involving the casting of 98 small wall units. The results indicate that the efficiency of a vibrator is related to its acceleration, optimum values being 100, 150 and 200 g for concrete with aggregate maximum sizes of 40, 20 and 10 mm respectively. For a given acceleration a vibrator with a high amplitude is likely to perform better than another with a lower amplitude and higher frequency. The study was limited to the assessment of the effect of amplitude and frequency upon the performance of internal vibrators having an outside diameter of up to 60 mm. Performance was represented by the radius of action within which the vibrator is capable of compacting the concrete to an optimum density; this is equivalent to approximately 98 percent of full compaction. The experimental details are given, the results are tabulated, and the conclusions are discussed of the 3 test series. Design recommendations are made related to externally driven vibrators (parallel- action type, pendulum-action type) and internally driven vibrators (electric type, pneumatic type).
Cement and Concrete AssociationWexham Spring
Slough SL3 6PL, Buckinghamshire, England
- Taylor, R W
- Publication Date: 1976-3
- Features: Appendices; Figures; Photos; References; Tables;
- Pagination: 24 p.
- TRT Terms: Acceleration (Mechanics); Aggregates; Amplitude (Physics); Compaction; Concrete; Density; Economic efficiency; Frequency (Electromagnetism); Performance; Vibration; Vibrators (Electricity)
- Uncontrolled Terms: Efficiency
- Old TRIS Terms: Internal vibration; Vibrators
- Subject Areas: Economics; Geotechnology; Highways; Materials;
- Accession Number: 00141533
- Record Type: Publication
- Report/Paper Numbers: 42.511 Tech. Rpt.
- Files: TRIS
- Created Date: Nov 17 1976 12:00AM