AN APPARATUS FOR THE RAPID ANALYSIS OF FRESH CONCRETE TO DETERMINE ITS CEMENT CONTENT
Following an assessment of the requirements of the construction industry, a mechanized apparatus to measure the cement content of fresh concrete has been devised. This report describes the apparatus, its operation and testing. The sequence of procedure built into the apparatus starts with the elutriation of a weighed sample of concrete with water, whereby cement and other fine particles are separated as a slurry. This is followed by sub-sampling, flocculation and measurement of the cement by weight in a constant volume vessel. The process takes five minutes and is controlled by a preset sequence timer. Details of the functions involved are given and their effect on overall precision and accuracy are discussed. In the absence of silt (i.e. aggregate of cement fineness), it is shown that the cement content of an 8 kg sample of concrete can be measured with a standard deviation of 21 g. A simple procedure for dealing with concretes containing appreciable amounts of silt is described; when this procedure is adopted, the standard deviation increases to 31 g. Future developments are outlined. These include analysis of fresh concrete for water content, aggregate grading and possibly pulverized-fuel ash content.
Cement and Concrete Association52 Grosvenor Gardens
London SW1W 0AQ, England
- Forrester, J A
- Black, P F
- LEES, T P
- Publication Date: 1974-4
- Features: Appendices; Figures; References; Tables;
- Pagination: 15 p.
- TRT Terms: Cement content; Flocculating agents; Mechanical analysis; Polymer concrete; Silts; Slurry; Standard deviation; Washing
- Old TRIS Terms: Constant volume mould; Flocculating; Slurries
- Subject Areas: Highways; Maintenance and Preservation; Materials;
- Accession Number: 00261475
- Record Type: Publication
- Report/Paper Numbers: 42.490 Tech. Rpt.
- Files: TRIS
- Created Date: Oct 22 1974 12:00AM