| 摘要: | 在多重障壁設計概念中，高完整性盛裝容器之服務年限需長達數百年之久，考量未來國內低放射性廢棄物最終處置場之廠址可能位於濱海區域，高完整性盛裝容器長期處於此環境下，對混凝土所造成之劣化與耐久性的影響相當顯著。
本研究延續先前研究團隊以活性粉混凝土製作低放射性廢棄物盛裝容器之配比參數、以振動60秒方式製作試體及利用90℃熱水養護一天。為提升活性粉混凝土運用於盛裝容器之工程性質及容器品質，首先針對石英砂含量及鋼纖維含量進行參數調整，決定參數最佳添加量之後，再降低水膠比，並分別進行抗壓強度、彈性模數、抗彎強度、直接拉力、劈裂強度和耐衝擊等硬固性質試驗，以及孔隙率、表面電阻率、超音波波速和乾燥收縮等耐久性質試驗。而試驗結果顯示，石英砂含量及鋼纖維含量分別於1.2及2.0%之耐久性質表現較為優異，水膠比則降低至0.18具有良好的硬固及耐久性質，為三組配比(W/B = 0.20、0.18及0.16)中的最佳化配比，並將最佳配比之各項試驗結果與國內外盛裝容器參考標準及規範進行比較皆符合要求標準值，顯示活性粉混凝土配比運用於高完整性盛裝容器上的潛力。
採用超音波波速試驗進行耐久性質檢測，此為非破壞性檢測方式，為提供後續盛裝容器檢測，與表面電阻率和孔隙率進行迴歸分析呈現高度相關性，顯示超音波波速能作為日後盛裝容器檢驗方法之一；將直接拉力強度及抗彎強度兩者與劈裂強度進行迴歸分析也呈現高度相關性，因此可透過劈裂試驗作為簡易快速評估活性粉混凝土之抗裂能力。
;The low-radioactive waste container concrete is different from the general concrete and must be considered for a longer period of durability.
This research continues the previous research team using reactive powder concrete to make low-level radioactive waste containers with mixing parameters, vibrating for 60 seconds to make specimens, and curing with hot water at 90℃ for one day. To improve the engineering properties and container quality of the reactive powder concrete used in the container, the parameters of the silica sand content and the steel fiber content are first adjusted, and the optimal addition amount of the parameters is determined, then the water-binder ratio is reduced, and the hardness tests such as compressive strength, elastic modulus, bending strength, direct tension, splitting strength, and impact resistance, as well as durability tests such as porosity, surface resistivity, ultrasonic pulse velocity, and drying shrinkage. The test results show that the silica sand and steel fiber content performed better at 1.2 and 2.0%, respectively, and the water-to-binder ratio was reduced to 0.18 to achieve the optimal ratio, showing the potential of the reactive powder concrete ratio to be used in high-integrity containers.
Ultrasonic pulse velocity test is used for durability quality inspection. To provide subsequent container inspection, it is highly correlated with surface resistivity and porosity in regression analysis, showing that ultrasonic pulse velocity can be used as a future container inspection as one of the methods. Regression analysis of both the direct tensile strength and the flexural strength and the splitting strength also shows a high correlation., so the splitting test can be used to evaluate the crack resistance of reactive powder concrete. |
