Unconfined Compression Behavior of Unsaturated Compacted Ca-Bentonite: Influence of Ca(OH)2 Solution and Elevated Temperature

• 발행기관: 한국방사성폐기물학회
• 저자명: Jun Ha Baek Yeowon Yoon Yunsik Gong Jihoon Lee Ho Young Jo Ji-Hoon Ryu
• 간행물 정보: 『Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT)』Vol.23 No.2, 191~210쪽, 전체 20쪽
• 주제분류: 공학 > 공학일반
• 파일형태: PDF
• 발행일자: 2025.06.30

국문 초록

This study investigated the unconfined compression behavior of unsaturated compacted Ca-bentonite (dry density = 1.6 Mg·m−3) after exposure to 0.02 M Ca(OH)2 solution and elevated temperatures (25℃ and 150℃) for up to 28 days. Unsaturated Ca-bentonite demonstrated brittle failure behavior regardless of the experimental conditions. At 25℃, the unconfined compression strength (qu) of Ca-bentonite specimens mixed with either deionized (DI) water (pH 6) or Ca(OH)2 solution (pH 12) was statistically unchanged. However, at 150℃, qu values increased significantly compared to 25℃. A similar trend was observed for Young’s modulus, indicating increased stiffness at higher temperatures. The enhancement is attributed primarily to reduced water content and corresponding increases in suction rather than direct mineralogical alteration, as confirmed by X-ray diffraction analysis. This study provides the early-stage mechanical response of unsaturated Ca-bentonite under repository-relevant thermal and alkaline conditions, offering understanding into its performance before saturation is achieved.

목차

1. Introduction

2. Materials and Methods

3. Results and Discussion

4. Conclusion

Conflict of Interest

Acknowledgements

REFERENCES

키워드

Ca-bentonite High-level radioactive waste disposal Buffer material Alkaline solution Unconfined compressive test Stress-strain behavior