Powdered cement in need of density determination.
"Lea's Chemistry of Cement and Concrete"
"Engineered Concrete Mix Design and Test Methods"
"Limes, Hydraulic Cement and Mortars"
"Structure & Performance of Cements"
"Pore Structure of Cement-Based Materials: Testing, Interpretation and Requirements"
"Materials Science of Concrete: Cement and Concrete-Trends and Challenges
"Advances In Cement Research"
"Cement And Concrete Research"
"Magazine Of Concrete Research"
CEMTECH, September 2005, Barcelona
N&S AMERICAN CEMENT, September 2005, Cancun
POWTECH, October 2005, Nürnberg
Annual ACAA Meeting, January 2006, New Orleans
BETONEX, February 2006, Moscow
EUROPEAN CEMENT, March 2006, London
ASHTECH, May 2006, Birmingham
CERAMITEC, May 2006, Munich
International Powder & Bulk Solids Conference/Exhibition, May 2006, Rosemont, Illinois
The density of cement plays a significant role both in its production and performance. The raw minerals are heated in huge ovens to promote chemical changes and this produces “clinker”. The final steps in cement manufacturing involve grinding (milling) and blending that produce the fine powder that is recognizable as cement. Every step in the manufacture of cement is checked by frequent physical tests, as is finished product, to ensure that it complies with all necessary specifications. Cement is ground to a particular fineness since the influence of particle size on the kinetics of cement hydration and development of strength is well known. For a given cement content, a reduction in median particle size generally produces a higher compressive strength. Consequently the fineness of Portland cements has been increased over the years to improve properties such as higher early strengths. Nevertheless, other effects of increased fineness, such as higher water demands and more rapid heat generation in the concrete cannot be ignored. Despite the availability of instrumental methods of measuring particle size distributions, the classical method of air permeametry remains. The density of cement should be known in connection with the design and control of concrete mixtures.
The permeameter most closely associated with the cement industry is the Blaine apparatus. This method requires an operator to pack a bed of powder to 50% porosity, +/- 0.5% using thumb pressure only. This means that the true density of the cement under test be known, except for Portland cement when a density of 3.15 g/cm3 is assumed. Notwithstanding the experimental difficulties, the method can only be as accurate as the density value assumed. Rather than assuming a density, or measuring by some wet method, it is recommended to use a dry gas pycnometer. These devices, like the Ultrapycnometer, can significantly improve the precision of the Blaine measurement and are preferred over wet methods because of their inherently clean mode of operation and elimination of solvent disposal problems.
Whether needed for the Blaine, or as a value in its own right, density has historically been determined by liquid displacement using, for example, kerosene or naptha. It is necessary to thermostat the liquid to within +/- 0.2oC. Disposal of used, wet sample is not usually considered in standard methods and multiple measurements necessarily incur a great deal of operator effort. Not so with automatic gas pycnometers. Samples as large as 135 cc bulk volume can be accommodated (thereby improving sampling statistics), purged of air automatically, run multiple times automatically and a printed report generated within minutes. The sample is recovered unharmed and dry, and the very same aliquot can be used for a subsequent Blaine analysis or other test. This method has already been adopted by a number of cement companies worldwide, and is standard in applications such as petroleum coke, pitch, coatings, carbon, cellular plastics, soils, ceramics, catalysts, etc. Read more about Quantachrome’s pycnometers here.
Abbreviated Quantachrome Density Reference List
These papers cite the use of Quantachrome's products and the list represents a fraction of all such papers. If you would like more examples, please contact us here.
"Influence of organic coatings on the stability of macrodefect-free cements exposed to water" M.Delucchi and G.Cerisola (2001) Construction and Building Materials,15, 351-359.
"Stability of portland cement-based binders reinforced with natural wollastonite micro-fibres" N.M.P.Low and J.J.Beaudoin (1994) Cement and Concrete Research, 24, 874-884.
"Porosity measurement of fragile agglomerates" S.Hogekamp and M.Pohl (2003) Powder Technology 130, 385-392.
"Aqueous injection moulding of porcelains " I.Santacruz, M.I.Nieto, R.Moreno, P.Ferrandino, A.Salomoni and I.Stamenkovic (2003) J. European Ceramic Society, 23, 2053-2060.
"Mechanical properties and microstructure of high alumina cement-based binders reinforced with natural wollastonite micro-fibres" N.M.P.Low and J.J.Beaudoin (1994) Cement and Concrete Research, 24, 650-660.
"Dispersions of oxide powders in organic liquids" M.V.Parish, R.R.Garcia and H.K.Bowen (1985) J. Material Science 20, 996 - 1008
"New methods characterizing avalanche behavior to determine powder flow" F.Lavoie, L.Cartilier and R.Thibert (2002) Pharm Res 19, 887 - 893.
"Mechanical behaviour of powders using a medium pressure flexible boundary cubical triaxial tester" V.M.Puri (2003) Journal of Process Mechanical Engineering 217, 233-241.
Due to copyright restrictions, Quantachrome cannot supply copies of the above papers but we will be pleased to direct you the the appropriate authors so you may make your request to them. Ask here.
Standards (methods, specifications etc) Click on links to order online / download. Note: provision of these links does not imply that Quantachrome's products are suitable for all of stated methods. This feature is provided as a convenience to those in the cement community. Quantachrome cannot entertain any questions regarding proper use of those standards not appropriate for Quantachrome's products. In such cases, you should contact the publishers.
Standard Test Method for Density of Hydraulic Cement ASTM C188-95(2003) ASTM International (liquid pycnometer method)
Standard Test Method for Specific Gravity of Soil Solids by Gas Pycnometer ASTM D5550-00(2000) ASTM International
Standard Test Method for Real Density of Calcined Petroleum Coke by Helium Pycnometer ASTM D2638-91(2002) ASTM International