Predicting the elastic properties of cement-based materials is
dependent on three types of information for each phase: 1) how
much of the phase is present, 2) how the phase is arranged in
the microstructure, and 3) the values of the elastic moduli of
the phase. Items number 1 and 2 are available in the CEMHYD3D
output, while item 3 must be measured independently. Cement
paste is extraordinarily complex elastically, and this
complexity further increases in concrete, as aggregates are
added. A finite element package for computing the elastic moduli
of composite materials has been written at NIST and has been
available for several years (Garboczi, 1998). The program takes
a 3-D digital image of a microstructure, assigns elastic moduli
tensors to each voxel according to what material phase is
present, and then computes the effective composite linear
elastic moduli of the material. This program is highly optimized
and has worked successfully for many different material
microstructures, including ceramics ( Roberts