Long-term changes in the chemical, microstructural, and transport properties of a low-pH cement shotcrete during operation of the Horonobe Underground Research Laboratory, Japan
Source abstract
Abstract
The properties of low-pH cement used in the geological disposal of radioactive waste may change through atmospheric carbonation and degradation caused by groundwater during the long-term operation of a repository. In this study, we investigated the effects of atmospheric carbonation and groundwater contact on the chemical, microstructural, and transport properties of shotcrete made from low-pH, high-fly-ash silica-fume cement (HFSC) over a period of 16 years in an underground research laboratory. In both carbonated and degraded zones of the HFSC shotcrete, capillary porosity increased for pores of < 300 nm in diameter, and the total porosity was higher than in undegraded zones. These changes in porosity may be associated with the decalcification of calcium–silicate–hydrate and decomposition of ettringite. Such changes were minor in altered zones of OPC shotcrete, indicating that HFSC shotcrete is less resistant to atmospheric carbonation and groundwater leaching under the studied conditions. However, the hydraulic conductivity in HFSC was low enough to fulfill the specific functional requirements of low-pH cements for geological disposal. • Carbonation and degradation altered the properties of low-pH cement shotcrete. • Elemental distributions changed and porosity increased in altered shotcrete zones. • Hydraulic conductivity was below the low-pH cement functional requirements.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: Concrete and Cement Materials Research · Chemical Synthesis and Characterization · Concrete Corrosion and Durability
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (68)
Show source-provided references
1. The essential role of cement-based materials in a radioactive waste repository10.1038/s44296-024-00025-9 ↗
2. Evolution of pore water chemistry during degradation of cement in a radioactive waste repository environment10.1016/0956-053X(92)90049-O ↗
3. Cement/clay interactions–a review: experiments, natural analogues, and modeling10.1016/j.wasman.2006.01.027 ↗
4. Alteration of bentonite by hyperalkaline fluids: a review of the role of secondary minerals10.1016/j.pce.2005.08.048 ↗
5. A comparative study of the modelling of cement hydration and cement–rock laboratory experiments10.1016/j.apgeochem.2011.04.004 ↗
6. The impact of cement on argillaceous rocks in radioactive waste disposal systems: a review focusing on key processes and remaining issues10.1016/j.apgeochem.2021.104979 ↗
7. Development and application of low-pH concretes for structural purposes in geological repository systems
8. A. Bodén, S. Pettersson, Development of rock bolt grout and shotcrete for rock support and corrosion of steel in low-pH cementitious materials, technical report by Svensk Kärnbränslehantering AB, SKB R-11-08, 2011.
9. Formulating a low-alkalinity, high-resistance and low-heat concrete for radioactive waste repositories10.1016/j.cemconres.2006.10.005 ↗
10. Design and characterization of low-heat and low-alkalinity cements10.1016/j.cemconres.2007.12.002 ↗
11. Development of low-pH cementitious materials for HLRW repositories: resistance against ground waters aggression10.1016/j.cemconres.2009.11.008 ↗
12. Characterization of Cebama low-pH reference concrete and assessment of its alteration with representative waters in radioactive waste repositories10.1016/j.apgeochem.2020.104703 ↗
13. Study of engineering properties of low-pH self-compacting concrete for concrete plug
14. Development and evaluation of low-pH concrete plugs suitable for high-level radioactive waste repositories
15. Micro-X-ray diffraction and chemical mapping of aged interfaces between cement pastes and Opalinus Clay10.1016/j.apgeochem.2020.104538 ↗
16. Development of low-pH cementitious materials based on CAC for HLW repositories: Long-term hydration and resistance against groundwater aggression10.1016/j.cemconres.2013.04.008 ↗
17. In situ interaction between different concretes and Opalinus Clay10.1016/j.pce.2013.11.004 ↗
18. In situ interactions between Opalinus clay and low alkali concrete10.1016/j.pce.2017.01.005 ↗
19. 5-year chemico-physical evolution of concrete–claystone interfaces, Mont Terri rock laboratory (Switzerland)
20. On the physico-chemical evolution of low-pH and CEM I cement pastes interacting with Callovo-Oxfordian pore water under its in situ CO2 partial pressure10.1016/j.cemconres.2014.01.010 ↗
21. Comparison of the chemo-mechanical behavior of low-pH cement exposed to calcareous water and to argillite pore water10.1016/j.apgeochem.2022.105392 ↗
22. Nuclear Energy Agency (NEA) · 2001
23. Development of low alkaline cement considering pozzolanic reaction for support system in HLW repository construction10.1557/PROC-932-110.1 ↗
24. Development of low-alkaline cement using pozzolans for geological disposal of long-lived radioactive waste10.2208/jscejf.64.92 ↗
25. M. Nakayama, H. Sato, Y. Sugita, S. Ito, M. Minamide, Y. Kitagawa, Low alkaline cement used in the construction of a gallery in the Horonobe Underground Research Laboratory, Proceedings of the ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management, Volume 2, Tsukuba, Japan, 2010, pp. 51–56, https://doi.org/10.1115/ICEM2010-40038.10.1115/ICEM2010-40038 ↗
26. M. Nakayama, H. Sato, Y. Sugita, A. Noguchi, Study on applicability of low alkaline cement in Horonobe Underground Research Laboratory Project; In-situ experiment at 140m gallery, technical report by Japan Atomic Energy Agency, JAEA-Research 2010-055, 2011 (in Japanese with English abstract), doi:10.11484/jaea-research-2010-055.
27. M. Nakayama, S. Sawada, H. Sato, Y. Sugita, Study on applicability of low alkaline cement in Horonobe Underground Research Laboratory Project; In-situ experiment at 250m gallery, technical report by Japan Atomic Energy Agency, JAEA-Research 2012-023, 2012 (in Japanese with English abstract), doi:10.11484/jaea-research-2012-023.
28. Confirmation of the applicability of low alkaline cement-based material in the Horonobe Underground Research Laboratory10.3327/jnuce.23.1_25 ↗
29. Y. Seno, M. Nakayama, Y. Sugita, K. Tanai, T. Fujita, Basic properties of the concrete using the low alkaline cement (HFSC) developed by JAEA, technical report by Japan Atomic Energy Agency, JAEA-Data/Code 2016-011, 2016 (in Japanese with English abstract), https://doi.org/10.11484/jaea-data-code-2016-011.
30. S. Anraku, C. Walker, C. Oda, M. Mihara, A. Honda, Hydration and degradation of High content Fly ash Silica fume Cement (HFSC), Proceedings of 15th International Congress on the Chemistry of Cement (ICCC 2019), Prague, Czech Republic, 2019.
31. M. Nakayama, Investigation of deterioration and effect on geological environment of low alkaline cement in Horonobe Underground Research Laboratory, technical report by Japan Atomic Energy Agency, JAEA-Data/Code 2020-009, 2020 (in Japanese with English abstract), https://doi.org/10.11484/jaea-data-code-2020-009.
32. Japan Industrial Standards (JIS), Fly ash for use in concrete, JIS A 6201:2015, 2015 (in Japanese).
33. K. Miyakawa, K. Nakata, Data of groundwater chemistry obtained in the Horonobe Underground Research Laboratory Project (FY2022), technical report by Japan Atomic Energy Agency, JAEA-Data/Code 2022-013, 2023, doi:10.11484/jaea-data-code-2022-013.
34. M.C. Alonso, J.L. García Calvo, C. Walker, M. Naito, S. Pettersson, I. Puigdomenech, M.A. Cuñado, M. Vuorio, H. Weber, H. Ueda, K. Fujisaki, Development of an accurate pH measurement methodology for the pore fluids of low pH cementitious materials, technical report by Svensk Kärnbränslehantering AB, SKB R-12-02, 2012.
35. The dynamics of capillary flow10.1103/PhysRev.17.273 ↗
36. Japanese Geotechnical Society (JGS), Test Methods for Permeability of Low-permeable Saturated Soils, JGS0312-2018, 2018 (in Japanese).
37. Hydraulic conductivity test system for compacted, 2-mm-thick bentonite specimens10.1016/j.sandf.2022.101210 ↗
38. Durability of concrete — degradation phenomena involving detrimental chemical reactions10.1016/j.cemconres.2007.09.015 ↗
39. Development of more accurate methods for determining carbonation depth in cement-based materials10.1016/j.cemconres.2023.107358 ↗
40. Durability of clinker reduced shotcrete: Ca2+ leaching, sintering, carbonation and chloride penetration10.1617/s11527-021-01644-7 ↗
41. Effect of global climatic change on carbonation progress of concrete10.1016/j.atmosenv.2007.05.028 ↗
42. Statistical analysis of the carbonation coefficient in open air concrete structures10.1016/j.conbuildmat.2011.10.028 ↗
43. Effects of temperature, humidity and CO2 concentration on carbonation of cement-based materials: a review10.1016/j.conbuildmat.2022.128399 ↗
44. Semi-dry natural carbonation at different relative humidities: degree of carbonation and reaction kinetics of calcium hydrates in cement paste10.1016/j.cemconres.2024.107777 ↗
45. Performance-based durability design, carbonation part 2 – classification of concrete10.1002/suco.201600067 ↗
46. Changes in microstructure characteristics of cement paste on carbonation10.1016/j.cemconres.2018.04.016 ↗
47. Gaseous carbonation of cementitious backfill for geological disposal of radioactive waste: Nirex Reference Vault Backfill10.1016/j.apgeochem.2019.04.020 ↗
48. Decomposition of synthesized ettringite by carbonation10.1016/0008-8846(92)90130-N ↗
49. Stability of calcium sulphoaluminate hydrates in water solutions with various pH values10.1016/0008-8846(91)90062-M ↗
50. Carbonation of the synthetic calcium silicate hydrate (C-S-H) under different concentrations of CO2: chemical phases analysis and kinetics10.1016/j.jcou.2019.10.001 ↗
51. Effects of carbonation on pore structure and diffusional properties of hydrated cement pastes10.1016/S0008-8846(97)00102-6 ↗
52. Impact of accelerated carbonation on OPC cement paste blended with fly ash10.1016/j.cemconres.2014.10.003 ↗
53. Experimental studies and thermodynamic modeling of the carbonation of Portland cement, metakaolin and limestone mortars10.1016/j.cemconres.2016.06.006 ↗
54. Permeability and porosity changes associated with cement grout carbonation10.1016/0008-8846(91)90092-V ↗
55. Investigation of the carbonation mechanism of CH and C-S-H in terms of kinetics, microstructure changes and moisture properties10.1016/j.cemconres.2013.11.015 ↗
56. Impact of carbonation on unsaturated water transport properties of cement-based materials10.1016/j.cemconres.2015.04.002 ↗
57. Carbonation of CH and C–S–H in composite cement pastes containing high amounts of BFS10.1016/j.cemconres.2009.10.020 ↗
58. Rapid measurement of the chloride diffusion coefficient in concrete from combination of non-steady-state migration experiment and EPMA
59. Japan Society of Civil Engineers (JSCE), Test Method for Effective Diffusion Coefficient of Chloride Ion in Concrete by Migration, JSCE-G571-2003, 2003 (in Japanese).
60. Magnesium perturbation in low-pH concretes placed in clayey environment—solid characterizations and modeling10.1016/j.cemconres.2015.09.002 ↗
61. Chemo-mechanical characterization of a low-pH model cement paste in magnesium bearing environment10.1016/j.cemconres.2024.107598 ↗
62. Mineralogical evolution of high-pH/low-pH cement pastes in contact with seawater10.3390/min14030285 ↗
63. Magnesium and calcium silicate hydrates, Part I: investigation of the possible magnesium incorporation in calcium silicate hydrate (C-S-H) and of the calcium in magnesium silicate hydrate (M-S-H)10.1016/j.apgeochem.2017.12.005 ↗
64. Alkali binding in cement pastes: Part I. The C-S-H phase10.1016/S0008-8846(99)00187-8 ↗
65. Friedel’s salt, Ca2Al(OH)6(Cl,OH)·2H2O: its solid solutions and their role in chloride binding10.1016/S0008-8846(98)00162-8 ↗
66. Stability of Friedel's salt in carbonated concrete structural elements10.1016/S0008-8846(96)85010-1 ↗
67. The effect of artificial leaching with HCl on chloride binding in ordinary Portland cement paste10.1016/j.cemconres.2020.105976 ↗
68. Chloride ion binding in cementitious materials: a review of influencing factors and control methods