摘要
摘要 國內低放射性廢棄物將進行最終處置，故處置場工程障壁設施的耐久性就顯得非常重要。低放射性廢棄物最終處置場處置窖主體由混凝土構成，台灣在四面環海情形下，處置場可能遭受外在環境多種因素的侵蝕。因此處置場障壁在此服務環境下，可能對混凝土造成損傷或劣化甚至影響其耐久性。 本研究針對低放射性廢棄物最終處置場可能使用之混凝土材料，以實驗室模擬其受硫酸鹽侵蝕下，探討混凝土材料長期在此環境之行為分析其耐久性之影響。利用費克第二定律的衍伸式得知在硫酸鹽侵襲下混凝土材料的擴散係數。並應用於反應動力方程式來計算其內部的應力、應變情形，再計算其剝落臨界值。後可得其劣化深度、劣化時間及劣化速率。若以台東地下水的硫酸鹽濃度來推估，結果顯示高完整性容器HIC配比較傳統配合設計ACI配比能夠抵抗硫酸鹽侵蝕。
並列摘要
Abstract The final disposal of low-level radioactive waste calls for engineered barriers for containment of the waste. Since concrete is a major component of the engineered barriers, the durability of concrete under adverse environment is of great importance for safety disposal of the wastes. This study aims at studying the durability of concrete, attacked by sulphate ions in the laboratory. The diffusion coefficient of concrete under sulphate attack was determined from laboratory specimens immersed in sulphate solution for varying period of time. Then the reaction kinetics of sulphate in concrete material was adopted to calculate the internal stress, strain, such that the time and depth of spalling can be estimated. Finally, the degradation rate of concrete with for different mixes can be determined. It was found that the concrete designed for the highly integrated containers exhibits improved ability in resisting sulphate attack than traditional concrete mixes.