Civil Engineering ETDs
Publication Date
Spring 5-16-2026
Abstract
Hydrogen generation in irradiated cementitious materials is a critical safety concern for nuclear waste encapsulation systems, as it may lead to pressure buildup and long-term durability issues. Accurate prediction of hydrogen yield requires a mechanistic understanding of water partitioning and phase evolution during cement hydration, which remain insufficiently captured in existing models.
This study develops a coupled thermodynamic–radiolysis framework integrating CemGEMS-derived phase assemblages with hydrogen yield formulations for OPC, WPC, and A-free cements over a range of water-to-cement ratios, saturation states, and carbonation conditions.
A bulk water-scaling approach reproduces first-order trends but shows strong sensitivity to the definition of water fraction. While this approach successfully reproduces first-order trends with increasing water content, it exhibits strong sensitivity to the definition of water fraction and limited predictive accuracy, with mean absolute percentage error (MAPE) values of approximately 20–25% with respect to experimental data. A phase-resolved formulation, incorporating phase-specific normalized yields and thermodynamically derived water fractions, significantly improved predictive accuracy (Mean Absolute Percentage Error (MAPE) ≈ 12% for OPC and A-free systems).
Results demonstrate that hydrogen generation is controlled by both water quantity and thermodynamic state. Increasing w/c enhances primarily via increased aqueous-phase water, while saturation assumptions lead to systematic increase in G(H2) (up to ~30%). Carbonation further increases hydrogen yield (10–17%) through portlandite depletion, C–S–H decalcification, and associated increases in pore solution.
Keywords
cement hydration, radiation, hydrogen generation, hydrogen yield, CemGems, cemdata18
Document Type
Thesis
Degree Name
Civil Engineering
Level of Degree
Masters
Department Name
Civil Engineering
First Committee Member (Chair)
Madura Pathirage
Second Committee Member
Fernando Moreu
Third Committee Member
Maryam Hojati
Fourth Committee Member
Osman Anderoglu
Recommended Citation
fatima, kaneez. "PREDICTION OF RADIOLYTIC HYDROGEN GENERATION IN CEMENTITIOUS MATERIALS USING THERMODYNAMIC HYDRATION MODELING." (2026). https://digitalrepository.unm.edu/ce_etds/380