Analysis of CCRL Proficiency Cements 151 and 152 Using the Virtual Cement and Concrete Testing Laboratory.
Analysis of CCRL Proficiency Cements 151 and 152 Using
the Virtual Cement and Concrete Testing Laboratory.
(1414 K)
Bullard, J. W.; Stutzman, P. E.
Cement and Concrete Research, Vol. 36, No. 8,
1548-1555, August 2006.
Keywords:
cements; concretes; computer models; hydration; particle
size distribution; building technology
Abstract:
To test the ability of the Virtual Cement and Concrete
Testing Laboratory (VCCTL) software to predict cement
hydration properties, characterization of mineralogy and
phase distribution is necessary. Compositional and
textural characteristics of Cement and Concrete
Reference Laboratory (CCRL) cements 151 and 152 were
determined via scanning electron microscopy (SEM)
analysis followed by computer modeling of hydration
properties. The general procedure to evaluate a cement
is as follows: (1) two-dimensional SEM backscattered
electron and X-ray microanalysis images of the cement
are obtained, along with a measured particle size
distribution (PSD); (2) based on analysis of these
images and the measured PSD, three-dimensional
microstructures of various water-to-cement ratios are
created and hydrated using VCCTL, and (3) the model
predictions for degree of hydration under saturated
conditions, heat of hydration (ASTM C186), setting time
(ASTM C191), and strength development of mortar cubes
(ASTM C109) are compared to experimental measurements
either performed at NIST or at the participating CCRL
proficiency sample evaluation laboratories. For both
cements, generally good agreement is observed between
the model predictions and the experimental data.
