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|Author(s):||Chiara F. Ferraris; Edward J. Garboczi;|
|Title:||Identifying improved standardized tests for measuring cement particle size and surface area|
|Published:||January 14, 2013|
|Abstract:||The Blaine fineness (Blaine) of a cement powder is a single parameter that is meant to characterize the specific surface area of a cement, and is assumed to be linked to physical and mechanical properties such as strength, setting time, and rheology. As the cement industry continues to develop more sophisticated blended cements, a single parameter will soon fail to capture the true complexity of the cement. The laser diffraction (LD) measurement of the entire particle size distribution is currently being used by cement producers for quality control of their cements while still measuring the Blaine, which is based on surface area measurement. Despite its wide use by the cement industry, LD is not a standardized test. This project‰s goal is to examine various tests, such as laser diffraction and Blaine, which measure the particle size distribution and total surface area of cement powder, and then determine the most appropriate test based on correlation with macro-properties of the cement paste or mortar. In addition, the shape of the cement particles, for a partial particle size range, was determined using X-ray computed micro-tomography (CT) and the relationship between X-ray CT, Brunauer-Emmett-Teller surface area method (BET) (surface area), laser diffraction, and Blaine measurements was explored. The more fundamental and sophisticated experiments, nitrogen BET and X-ray CT, was used as ,ground truthŠ to critically evaluate the laser PSD and Blaine fineness measurements. The standardization of the laser diffraction test method is proposed. PUBLICATION AVAILABLE: http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rrd_382.pdf.|
|Proceedings:||transportation research board annual meeting|
|Dates:||January 13-17, 2013|
|Keywords:||Particle size distribution, Laser diffraction, Blaine, Xray-CT|
|Research Areas:||Building and Fire Research, Concrete/Cement|
|PDF version:||Click here to retrieve PDF version of paper (462KB)|