The interfacial transition zone (ITZ) in hydrated cement paste has highly modified microstructures near embedded materials such as aggregates. The ITZ has a significant influence on the properties of concrete (stiffness, strength, and permeability). This study proposes a framework for constructing virtual 3D ITZ microstructures with a porosity gradient as an alternative to real 3D ITZ microstructures. Virtual two-phase (pore/solid) 3D ITZ samples are reconstructed by extending the conventional stochastic optimization process for random heterogeneous materials. The virtual samples are reconstructed to reproduce probabilistic descriptions of pore microstructures of the ITZ. The pore microstructures are described by low-order probability functions obtained from synchrotron μ-CT images of bulk cement paste samples of varying porosities. The properties (stiffness, thermal conductivity) of the reconstructed samples were evaluated through virtual experiments, and the anisotropic properties correlate with characteristics of the microstructures. The proposed framework can be used as an accelerated ITZ performance evaluation tool.
Bibliographical noteFunding Information:
This research was supported by the National Research Foundation of Korea (NRF-2016R1D1A1B03931635 and NRF-2017R1A4A1014569). This research was also supported by the Korea Institute of Energy Technology Evaluation and Planning (No. 20174030201480). μ-CT images were obtained from the synchrotron operated by the Pohang Accelerator Laboratory (PAL) in the Republic of Korea.
© 2019 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Building and Construction
- Materials Science(all)