Speaker
Description
Fiber-reinforced cementitious composites such as Geosynthetic Cementitious Composite Mats (GCCMs) are increasingly used in cold-region infrastructure, yet their durability under repeated freeze–thaw cycles (FTCs) is still uncertain at the microstructural scale. This limits confidence in long term performance as freeze–thaw variability increases in many regions.
We studied a polyester fiber reinforced cementitious composite subjected to 100 laboratory-controlled FTCs under closed-system saturation. High resolution X-ray micro computed tomography (micro CT) was used to track damage evolution, and deep learning segmentation quantified changes in connected pore and crack networks while relating damage to the local fiber distribution.
The combined pore+crack volume fraction increased from ~10% to ~21% on average, with localized damage up to ~24.8% in regions with sparse fiber density. Thermo-mechanical analysis indicates that differential thermal expansion between ice and the surrounding matrix generates hoop stresses far exceeding the tensile strength of the composite (2.4 MPa), and much larger than stresses expected from crystallization pressure alone, identifying thermal dilation mismatch as the dominant cracking driver under full saturation. In addition, polyester fibers can coincide with preferential sites for ice nucleation and fracture initiation.
These results provide microstructural constraints to improve freeze thaw-resistant design, emphasizing pore structure control and optimization of the fiber matrix interface for cold-region applications, ultimately supporting more resilient infrastructure under harsh and changing climates.
| Country | Belgium |
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