本研究建立了混凝土障壁的偶合熱-水汽-二氧化碳傳輸模型、熱漲冷縮與濕漲乾縮模型，藉此對儲存低放射性廢棄物之淺地層處置場的混凝土障壁進行耐久性評估。 在耦合熱-水汽-二氧化碳傳輸分析中本研究採用有限元素軟體ABAQUS，輔以副程式及批次檔建立模型，並對溫度、相對濕度、二氧化碳濃度歷時曲線進行討論。根據分析結果可知水汽傳輸結果的些微改變就有可能造成截然不同二氧化碳傳輸結果。依此模型為基礎本研究繼續對水氣邊界條件與水汽擴散率D_m進行參數影響分析，結果顯示增加水氣擴散率會加速初期混凝土內水分的流失及對二氧化碳傳輸產生極大的影響。 在熱漲冷縮濕濕漲乾縮分析中本研究以之前建立的傳輸模型為基礎，探討熱漲冷縮與濕漲乾縮產生的力學反應，並對位移、應力歷時圖進行討論，結果顯示熱漲冷縮與濕漲乾縮並不會使混凝土產生裂縫。依此模型為基礎本研究繼續對溫度邊界條件與自由水汽收縮係數β進行參數影響分析，結果顯示這兩項參數都會對混凝土的位移及應力結果產生極大的影響。 To evaluate the durability of reinforced concrete structures which stored the Low-level radioactive exposed to various aggressive environments, this study established three numerical simulation model, coupled heat-moisture- carbon dioxide transfer model, thermal expansion/contraction model and wetting expansion/drying shrinkage model. In this study we use subroutine, batch file and ABAQUS which is finite element software to establish coupled heat-moisture- carbon dioxide transfer model, according to the result we can find that the small change of moisture transfer result can create an enormous change to carbon dioxide transfer result. Based on this model, this study chooses moisture diffusivity and moisture boundary condition to run parameters impact analysis, according to the result the change of moisture diffusivity will cause enormous change to the carbon dioxide transfer result. Basic of the transfer model, this study established thermal expansion/contraction model and wetting expansion/drying shrinkage model. The result shows that thermal expansion/contraction and wetting expansion/drying shrinkage does not make concrete crack. Based on this model, this study chooses moisture contraction coefficient and temperature boundary condition to run parameters impact analysis, according to the result the change of moisture contraction coefficient and temperature boundary condition will cause enormous change to the result of displacement and stress.
