|Abstract: ||混凝土耐久性試驗主要用於檢測混凝土抵抗氯離子侵入能力，類型分為離子自然擴散及利用電場加速離子傳輸。自然擴散常使用貯鹽試驗(Ponding test)，電場加速常使用快速氯離子滲透試驗(RCPT)、快速氯離子傳輸試驗(RCM)及加速氯離子傳輸試驗(ACMT)等，其中RCPT因快速簡單而被廣泛使用，但累積電量會受到混凝土添加物的影響，進而誤導評估結果，因此常需使用其他耐久性評估試驗輔助判斷。 本研究為探討一般耐久性試驗使用於新型態的特殊混凝土之適用性，使用矽質混凝土及相同粒料用量之一般混凝土進行比較，採用四種水灰比(0.3、0.35、0.40、0.45)，於齡期7天、28天、90天進行RCPT試驗、貯鹽試驗、健度試驗及乾濕循環試驗，比較兩類混凝土試驗結果之差異性，深入研究各耐久性試驗使用於新型態的特殊混凝土之可行性。 RCPT試驗結果顯示，齡期7天、28天、90天矽質混凝土累積電量皆較一般混凝土低，累積電量隨著齡期增加而降低，但氯離子穿透齡期90天之矽質混凝土試體，未穿透齡期90天低水灰比一般混凝土試體。 貯鹽試驗結果顯示，齡期7天、28天、90天矽質混凝土氯離子滲透深度皆深於一般混凝土，且滲透現象不同於一般混凝土之擴散現象，擴散係數不予計算。 健度試驗結果顯示，兩類混凝土完全不受氫氧化鈉溶液影響，浸置於鹽酸及乙酸中，損失率差異性不大，硫酸鈉試驗組兩者差異性較大，一般混凝土損失率不高，矽質混凝土因硫酸鈉膨脹而完全碎裂。 乾溼循環試驗結果顯示，矽質混凝土在經過乾溼循環後壓力強度高於未經過乾溼循環之試樣；RCPT試驗累積電量低於未經過乾溼循環之試樣，但氯離子仍穿透5公分試體；貯鹽試驗之自然滲透深度太深，擴散係數亦不計算。 本研究使用之矽質混凝土累積電量雖低，但氯離子卻穿透5公分試體，貯鹽試驗之自然擴散深度亦不理想，表示若單以RCPT試驗累積電量評估混凝土抵抗氯離子侵入能力將會產生誤差，進而導致耐久性評估結果不準確。|
The concrete durability experiments mainly use to exam the ability of concrete to resist the invasion of chloride, they are divided into two models: the ion diffusion and the migration. The salt ponding test is commonly used in the traditional diffusion action. Because the chloride analyses are time-consuming, laborious, and expensive, the chloride migration test which is applied with electrical field has been widely used in recent year. RCPT is commonest used to evaluate the chloride permeability of concrete. The experimental procedures are easy and time-saving, but the result will be affected by the mineral additives include fly ash, slag, and silica fume. Therefore, it is necessary to use other durability tests to assist the assessment. This research uses two kinds of concrete, siliceous concrete and Portland cement concrete (OPC), to discuss the availability of specific concrete for durability experiment. The specimens included four water binder ratios (0.30, 0.35, 0.40, 0.45) were cured for 7, 28, 91 days. Using the RCPT, salt ponding test, soundness test, and dry-wet cycle test to compare the difference between the two series concrete. In the RCPT, the result shows that the charge passed of Siliceous concrete is lower than OPC at 7days, 28 days and 90 days aged, charge passed decrease along with the curing age. In the chloride profiles after RCPT, it shows the siliceous concrete is penetrated through the 5-cm specimen by chloride. However, the OPC of lower w/b ratios is not penetrated the specimen through by chloride. In the salt ponding test, the result shows that the penetration depths of siliceous concrete are deeper than OPC in all curing ages. Because the chloride penetration behavior of siliceous concrete is different from the traditional diffusion model of OPC, this method is unable to obtain the diffusion coefficient of siliceous concrete. According to soundness experiment, both of the two series concrete isn’t influenced by Sodium Hydroxide Solution (NaOH), and the difference of the weights loss rate is little in Acetic Acid(CH3COOH). However, the specimens are immersed in Sodium Sulfate(Na2SO4), the difference of the weights loss rate is very high in siliceous concrete and OPC. Siliceous concrete is cracked because the volume expansion of Sodium Sulfate. The compression strength of OPC after dry-wet cycle is usually lower than the original OPC, but the compression strength of siliceous concrete after dry-wet cycle is stronger than the original siliceous concrete. The structure of siliceous concrete is more compact after the dry-wet cycle. Although the charge passed of Siliceous concrete is lower in RCPT, the chloride can penetrate through the specimen. Because the diffusion model of the new material concrete is different from the traditional OPC, the diffusion depth of salt ponding test is unsuitable in siliceous concrete. It has a blind spot that only using the charge passed from RCPT to determine the chloride permeability of concrete. Thus, it is necessary to calibrate against the other experiments.