Three-Dimensional Shape Analysis of Coarse Aggregates: New Techniques for and Preliminary Results on Several Different Coarse Aggregates and Reference Rocks.
Three-Dimensional Shape Analysis of Coarse Aggregates:
New Techniques for and Preliminary Results on Several
Different Coarse Aggregates and Reference Rocks.
(1689 K)
Erdogan, S. T.; Quiroga, P. N.; Fowler, D. W.; Saleh, H.
A.; Livingston, R. A.; Garboczi, E. J.; Ketcham, P. M.;
Hagedorn, J. G.; Satterfield, S. G.
Cement and Concrete Research, Vol. 36, No. 9,
1619-1627, September 2006.
Keywords:
aggregates; concretes; rheology; mechanical properties;
x ray tomography; geometry
Abstract:
The shape of aggregates used in concrete is an important
parameter that helps determine many concrete properties,
especially the rheology of fresh concrete and early-age
mechanical properties. This paper discusses the sample
preparation and image analysis techniques necessary for
obtaining an aggregate particle image in 3-D, using
X-ray computed tomography, which is then suitable for
spherical harmonic analysis. The shapes of three
reference rocks are analyzed for uncertainty
determination via direct comparison to the geometry of
their reconstructed images. A Virtual Reality Modeling
Language technique is demonstrated that can give quick
and accurate 3-D views of aggregates. Shape data on
several different kinds of coarse aggregates are
compared and used to illustrate potential mathematical
shape analyses made possible by the spherical harmonic
information.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899