Random Material Property Fields of 3D Concrete Microstructures Based on CT Image Reconstruction.

Area of Science:

• Materials Science
• Civil Engineering
• Computational Mechanics

Background:

• Concrete exhibits a highly heterogeneous microstructure due to its constituent materials (pores, cement paste, aggregates).
• Understanding the spatially varying elastic properties of concrete is crucial for accurate structural analysis and design.

Purpose of the Study:

• To determine the random, spatially varying elastic properties of concrete at various scales.
• To investigate the influence of microstructural heterogeneity on mechanical behavior.

Main Methods:

• Reconstruction of concrete microstructure using computed tomography (CT) images.
• Quantification of local volume fractions of constituents.
• Generation of mesoscale random fields of the elasticity tensor via the moving window method and computational homogenization.

Main Results:

• Computed mesoscale random fields of the elasticity tensor based on statistical volume elements.
• Quantified variability in the local volume fraction of concrete constituents.
• Established a link between microstructural randomness and mechanical response.

Conclusions:

• The study successfully determined spatially varying elastic properties of concrete.
• The methodology allows for assessing the impact of microstructural randomness on concrete's mechanical behavior.
• This approach provides a foundation for more accurate predictive models of concrete performance.