由於台灣四面環海，且處於亞熱帶與熱帶地區，所以對鋼筋混凝土結構物而言，屬於腐蝕性侵蝕的環境。而當氯離子侵入混凝土中，達到一定的含量時，鋼筋表面的鈍化層(passive layer)會被破壞，進而使鋼筋腐蝕，降低結構物的強度與勁度，對結構物造成極大威脅。因此，鋼筋腐蝕已成為影響結構物使用壽命和安全性的主要因素之一。
本研究藉由在混凝土拌合時，添加不同濃度的氯鹽，來模擬鋼筋在不同氯鹽濃度下的腐蝕情況，希望能藉此找出誘發鋼筋腐蝕之臨界氯離子濃度。另外使用非破壞檢測的方式來判斷鋼筋腐蝕的情況。而非破壞檢測是使用美國James儀器公司製作的Gecor 8腐蝕電流儀進行試驗，最後再將試體破壞取出鋼筋觀察鋼筋表面實際的腐蝕情況。另外再做初始酸鹼值試驗和酸中和試驗來縮小臨界氯離子濃度的範圍。
臨界氯離子濃度以[Cl-]/[OH-]表示時，0.45、0.55、0.65的OPC以及水膠比0.55使用50%的爐石取代量的臨界值分別1.095、0.99、1.018和5.185。以[Cl-]/[H+]表示時，0.45、0.55、0.65的OPC以及水膠比0.55使用50%的爐石取代量的臨界值分別0.0057、0.0057、0.0063和0.014。使用爐石取代部分水泥可以使鋼筋開始腐蝕的臨界氯離子濃度提高，增加對鋼筋的保護能力，提高耐久性。

Taiwan is surrounded by sea, so the reinforced concrete structures are exposed to corrosive environments. When chloride ions penetrated into the concrete, to reach a certain concentration, the reinforcing steel surface passive layer be destroyed and cause the steel corrosion, it will reduce structure strength and stiffness. Therefore, the reinforcing steel corrosion is the main factors to structures life and security.
This study add different concentrations of chloride salts when the concrete mixing, to simulate the reinforcing steel corrosion situation at different chloride concentrations, to identify the critical chloride ion concentration. Use non-destructive testing to determine the corrosion situation of reinforcing steel. Final destruct the specimen and remove the reinforcing steel to observe actual corrosion. Do other tests like initial pH value and acid neutralization tests to narrow the critical range of chloride ion concentration.
Critical chloride ion concentration thresholds [Cl-] / [OH-] for OPC 0.45, 0.55, 0.65 and 0.55-50% GGBS are 1.095, 0.99, 1.018 and 5.185, respectively. [Cl-] / [H+] for OPC 0.45, 0.55, 0.65 and 0.55-50% GGBS are 0.0057, 0.0057, 0.0063 and 0.014, respectively. Using slag replace part of cement will increased the critical chloride ion concentration, increasing the protection of steel capacity, improve durability.

目錄

口試委員會審定書 #
誌謝 II
中文摘要 III
ABSTRACT IV
目錄 V
表目錄 X
照片目錄 XVI
Chapter 1 第一章 緒論 1
1.1 研究動機……………………….. 1
1.2 研究目的 1
1.3 研究流程 2
Chapter 2 第二章 文獻回顧 4
2.1 鋼筋腐蝕的機制 4
2.1.1 鋼筋腐蝕的原理 4
2.1.2 影響鋼筋腐蝕的因素 4
2.2 混凝土內含氯離子 6
2.2.1 氯離子的來源 6
2.2.2 混凝土內氯鹽含量之相關規範 7
2.3 添加卜作嵐材料 7
2.3.1 矽灰 8
2.3.2 飛灰 8
2.3.3 爐石 9
2.4 混凝土內鋼筋腐蝕的檢測方法和依據 12
2.4.1 腐蝕電位(Corrosion Potential) 12
2.4.2 鋼筋腐蝕速率(Corrosion Rate) 13
2.4.3 混凝土電阻係數(Electrical Resistance) 15
2.4.4 失重法 17
2.4.5 綜合比較 17
2.5 硬固混凝土的化學性質 17
2.5.1 硬固混凝土的酸鹼值(pH值)量測 17
2.5.2 硬固混凝土的酸中和能力(ANC) 18
2.6 氯離子鍵結能力 19
2.6.1 水泥中C3A對氯離子鍵結能力的影響 19
2.6.2 爐石對氯離子鍵結能力的影響 19
2.7 臨界氯離子濃度 19
2.7.1 臨界氯離子濃度的定義 20
2.7.2 臨界氯離子濃度的表達方式 20
Chapter 3 第三章 實驗計畫與試驗設備 36
3.1 實驗內容……………………………. 36
3.2 試驗材料 36
3.3 試驗儀器 37
3.4 水泥砂漿拌合流程 38
3.5 水泥砂漿抗壓強度試驗 38
3.5.1 試驗材料與設備 38
3.5.2 試驗方法 38
3.6 氯離子含量滴定試驗 39
3.6.1 試驗材料與設備 39
3.6.2 水溶性氯離子含量試驗 39
3.6.3 酸溶性氯離子含量試驗 39
3.7 水泥砂漿PH值試驗 40
3.7.1 試驗材料與設備 40
3.7.2 試驗方法 40
3.8 水泥砂漿酸中和能力試驗 40
3.8.1 試驗材料與設備 41
3.8.2 試驗方法 41
3.9 鋼筋腐蝕電流量測試驗 41
3.9.1 試驗材料與設備 41
3.9.2 試驗方法 41
3.10 鋼筋表面實際腐蝕情況 42
3.10.1 試驗材料與設備 42
3.10.2 試驗方法 42
Chapter 4 第四章 試驗結果與討論 55
4.1 水泥砂漿抗壓強度試驗結果與分析 55
4.1.1 氯離子含量對抗壓強度之影響 55
4.1.2 水膠比對抗壓強度之影響 55
4.1.3 爐石取代對抗壓強度之影響 56
4.2 水泥砂漿的PH值試驗和酸中和能力試驗結果與分析 56
4.2.1 氯鹽添加量對PH值和酸中和能力的影響 56
4.2.2 水膠比對PH值的影響 57
4.2.3 爐石取代對PH值的影響 57
4.2.4 水膠比對酸中和能力的影響 58
4.2.5 爐石取代對酸中和能力的影響 58
4.3 氯離子滴定試驗結果與分析 58
4.3.1 酒精燈直接加熱法和隔水加熱法比較 59
4.3.2 水溶法結果與討論 59
4.3.3 酸溶法結果與討論 59
4.3.4 酸溶法和水溶法綜合比較與討論 60
4.4 鋼筋腐蝕電流密度試驗結果與討論 60
4.4.1 水膠比對腐蝕電流密度的影響 60
4.4.2 爐石取代對腐蝕電流密度的影響 61
4.4.3 90天腐蝕電流密度和180天腐蝕電流密度的比較和討論 61
4.5 鋼筋表面實際腐蝕情形結果與分析 61
4.5.1 氯離子添加量對鋼筋表面實際腐蝕情況的影響 61
4.5.2 腐蝕電流密度和鋼筋表面實際腐蝕情況的關係與討論 62
4.6 臨界氯離子濃度 62
4.6.1 以總氯離子表示 62
4.6.2 以自由氯離子表示 63
4.6.3 以[Cl-]/[OH-]表示 63
4.6.4 以[Cl-]/[H+]表示 64
4.6.5 綜合比較 64
Chapter 5 第五章 結論與建議 92
5.1 結論 92
5.1.1 水泥砂漿性質之結論 92
5.1.2 鋼筋腐蝕趨勢之結論 92
5.1.3 臨界氯離子濃度之結論 93
5.2 建議 93
參考文獻 95

[1]Uhlig, H.H. and Revie, R.W. Corrosion and Corrosion Control. New York: Wiley, 1985, pp.28-35.
[2]Andrade, C., Castellote, M., Sarria, J. and Alonso, C., “Evolution of Pore Solution Chemical, Electroosmosis and Rebar Corrosion Rate Induced by Realkalisation,” Materials and Structures, Vol.32, pp.427-436,1999.
[3]Shalon, R. and Raphael, M., “Influence of Sea Water on Corrosion of Reinforcement,” ACI Journal, Vol. 55, No.12, pp.1251-1268,1959.
[4]Fraczek, J., “A Review of Electrochemical Principles as Applied to Corrosion Corrosion of Steel in a Concrete or Grout Environment,” ACI SP 102-2, pp. 13-24, 1987.
[5]Hussain, S.E. and Al-Saadoun, S.S., “Effects of Cement Composition on Chloride Binding and Corrosion of Reinforcing Steel in Concrete, “ Cement and Concrete Research, Vol. 21, No.6, pp.777-794, 1991.
[6]Bertolini, L., Elsener, B., Pedeferri, P. and Polder, R., Corrosion of Steel in Concrete, New York: Wiley , 2004.
[7]Alonso, C., Castellote, M. and Andrade, C., “Chloride threshold dependence of pitting potential of reinforcements,” Electrochimica Acta ,vol. 47, pp. 3469–3481,2002.
[8]Schiessl, P. and Lay, S., Influence of concrete composition, in: H. Bohni (Ed.), Corrosion in Reinforced Concrete Structures, Woodhead Publishing Limited, Cambridge, 2005, pp. 91–134.
[9]Tuutti, K., Effect of cement type and different additions on service life, in: Proc. Int. Conf. "Concrete 2000", Dundee, Scotland, UK, E & FN Spon, Chapman & Hall, London, 1993, pp. 1285–1295.
[10]Hansson, C.M. and Sorensen, B., “The threshold concentration of chloride in concrete for the initiation of reinforcement corrosion, in: N.S. Berke, V. Chaker, D. Whiting (Eds.),” Corrosion rates of steel in concrete, ASTM STP 1065, pp. 3–16,1990.
[11]Pettersson, K., ” Chloride threshold value and the corrosion rate in reinforced concrete,” Proc. of the Nordic Seminar, Lund, 1995, pp. 257–266.
[12]Poupard, O., Ait-Mokhtar, A. and Dumargue, P., “Corrosion by chlorides in reinforced concrete: determination of chloride concentration threshold by impedance spectroscopy,” Cement and Concrete Research, vol.34, pp.991–1000, 2004.
[13]Andrade, C., Page, C.L., “Pore solution chemistry and corrosion in hydrated cement systems containing chloride salts: a study of cation specific effects,” British Corrosion Journal, vol. 21, pp. 49–53, 1986.
[14]Arya, C., Buenfeld, N.R. and Newman, J.B., “Factors influencing chloride-binding in concrete,” Cement and Concrete Research, vol. 20, pp. 291–300, 1990.
[15]Tritthart, J., “Chloride binding in cement II the influence of the hydroxide concentration in the pore solution of hardened cement paste on chloride binding,” Cement and Concrete Research, vol. 19, pp. 683–691, 1989.
[16]Hansson, C.M., Frolund, T., Markussen, J.B. “The effect of chloride cation type on the corrosion of steel in concrete by chloride salts,” Cement and Concrete Research, vol. 15, pp. 65–73, 1985.
[17]Jinxia, X., Linhua, J., Weilun, W., Jiang, Y., “Influence of CaCl 2 and NaCl from different sources on chloride threshold value for the corrosion of steel reinforcement in concrete,” Construction and Building Materials, vol.25, pp.663-669, 2011.
[18]黃兆龍，「混凝土中氯離子含量檢測技術及試驗」，訓練班教材，民國九十三年。
[19]日本土木學會，「高爐石粉末應用於混凝土施工指針」，平成8年。
[20]ACI Committee 226, “Silica Fume in Concrete”, ACI Materials Journal, Vol. 84, No. 6, pp. 158-166, 1987.
[21]李修齊，「高強度混凝土水中磨耗性質之機理探討」，碩士論文，國立台灣大學土木工程研究所，民國八十六年七月。
[22]宋佩瑄，「矽灰在混凝土工程上之發展與應用」，結構工程，第113-120頁，民國七十七年。
[23]Manera, M., Vennesland, Q. and Bertolini, L., “Chloride threshold for rebar corrosion in concrete with addition of silica fume,” Corrosion Science vol. 50, pp. 554–560, 2008.
[24]Larsen, C.K.” Chloride binding in concrete,” Norwegian University of Science and Technology, 1998.
[25]Page, C.L., Vennesland, Q., “Pore solution composition and chloride binding capacity of silica fume-cement pastes,” Materials and Structures, vol. 19, pp. 19–25, 1983.
[26]Thomas, M. “Chloride threshold in marine concrete,” Cement and Concrete Research, vol. 26, pp. 513–519, 1996.
[27]Oh, B.H., Jang, S.Y., Shin, Y.S., “Experimental investigation of the threshold chloride concentration for corrosion initiation in reinforced concrete structures,” Magazine of Concrete Research, vol. 55, pp. 117–124, 2003.
[28]Schiessl, P., Breit, W., “Local repair measures at concrete structures damaged by reinforcement corrosion— aspects of durability,” The Royal Society of Chemistry, Cambridge, 1996, pp. 525–534.
[29]Dhir, R.K., Jones, M.R. “Development of chloride-resisting concrete using fly ash,” Fuel, vol. 78, pp. 137–142, 1999.
[30]Diamond, S., “Effects of two danish fly ashes on alkali contents of pore solutions of cement-fly ash pastes,” Cement and Concrete Research, vol. 11, pp. 383–394, 1981.
[31]Kawamura, M., Kayyali, O.A., Haque, M.N., “Effects of fly ash on pore solution composition in calcium and sodium chloride-bearing mortars,” Cement and Concrete Research, vol. 18, pp. 763–773, 1988.
[32]ACI Committee 233,”Ground Granulated Blast-Furnace Slag as a Cementitious Constituent in Concrete,” American Concrete Institute, Detroit, 1996.
[33]公共工程高爐石使用手冊
[34]Hogan, F.J., Meusel, J.W., “Evaluation for Durability and Strength Development of a Ground Granulated Blast-Furnace Slag,” Cement, Concrete, and Aggregates, vol. 3, no.1, pp.40-52, 1981.
[35]「高爐石粉不同替代率水泥砂漿強度成長趨勢研究」，中聯爐石公司品管研發處研發報告。
[36]Yuebo, L.R.C., Changyi, W., Xiaoming, H., “Study of chloride binding and diffusion in GGBS concrete,” Cement and Concrete Research, vol. 33, no.1, pp.1–7, 2003.
[37]An, C., Ran, H., Jiann-Kuo, W., Cheng-Hsin, C., “Influence of GGBS on durability and corrosion behavior of reinforced concrete,” Material Chem Phys, vol. 93, pp.404–411,2005.
[38]Arya, C., Buenfeld, N.R., Newman, J.B., “Factors influencing chloride binding in concrete,” Cement Concrete Research, vol.20, no.2, pp.291–300,1990.
[39]Al-Gahtani, A.S., Rasheeduzzafar, Al-Saadoun, S.S., “Rebar corrosion and sulfate resistance of blast-furnace slag cement,” J Mater Civil Eng. , vol.6, no.2, pp.223–233,1993.
[40]VK Gouda, V.K., ”Corrosion and corrosion inhibition of reinforced steel. I. Immersed in alkaline solutions,” Br Corros J, vol.5, pp.198–203, 1970.
[41]Sergi, G., Glass, G.K., “A method of ranking the aggressive nature of chloride contaminated concrete,” Corrosion Science vol. 42, pp.2043-2049,2000.
[42]Ha-Won, S., Min-Sun J., Chang-Jong L., Sang-hyo K., Ann,K.Y., “Influence of Chemistry of Chloride Ions in Cement Matrix on Corrosion of Steel,” ACI Materials Journal,Vol.107,No.4,July-August 2010.
[43]Liu, Y., Weyers, R.E., “Comparison of Guarded and Unguarded Linear Polarization CCD Devices with Weight Loss Measurements,” Cement and Concrete Research, Vol. 33, pp. 1093-1101,2003.
[44]Broomfield, J.P., Rodriguez, J., Ortega, L.M., “Corrosion Rate and Life Prediction for Reinforced Concrete Structures”, Structure Faults and Repairs Symposium, Historic University of Edinburgh, Scotland, 1993.
[45]葉為忠，張建智，黃 然，洪啟哲，游云辰，「既有 RC 結構物鋼筋腐蝕量測技術及評估準則之研究」， 內政部建築研究所委託研究報告，2010。
[46]ASTM C-876, “Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete”, 1999.
[47]Clear, K.C., “Measuring the rate of corrosion of steel in field concrete structures,” Transportation Research Record 1211, Transportation Research Board, National Research Council, Washington DC, 1989.
[48]Rodriguez, J., Ortega, L.M., Garcia, A.M., “Corrosion Rate Measurements in Concrete Bridges by Means of the Linear Polarization Technique Implemented in a Field Device,” ACI fall convention, Minneapolis, Minnesota, November 1993.
[49]Gonza’lez, J.A., Algaba, S., Andrade, C., “Corrosion of reinforcing bars in carbonated concrete ,” Br Corros J, vol. 15, no. 3, pp.135 – 139, 1980.
[50]Gonza’lez, J.A., Andrade,C., Alonso, C., Feliu, S., “Comparison of rates of general corrosion and maximum pitting penetration on concrete embedded steel reinforcement,” Cement and Concrete Research, vol. 25, no. 2, pp. 257 – 264,1995.
[51]Andrade, C., Castelo, V., Alonso, C., Gonzalez, J.A., “The determination of the corrosion rate of steel embedded in concrete by the polarization resistance and AC impedance methods, in: V. Chacker (Ed.),” Corrosion Effect of Stry Currents and Techniques for Evaluating Corrosion of Rebars in Concrete, ASTM Spec Tech Publ, 906, pp. 43 – 63,1984.
[52]Alonso, C., Andrade, C., Castellote, M., Castro, P., “Chloride threshold values to depassivate reinforcing bars embedded in a standardized OPC mortar,” Cement and Concrete Research, vol. 30, pp.1047 – 1055, 2000.
[53]Stern, M., Geary, A.L., “Electrochemical Polarisation. I. A Theoretical Analysis of the Shape of Polarisation Curves”, J. Electrochem. Soc., Vol. 104, pp. 56-63, 1957.
[54]ASTM G3-89, “Standard Practice for Convention Applicable to Electrochemical Measurement in Corrosion Testing”, 1994.
[55]Andrade, J.A., “The Determination of the Corrosion Rate of Steel Embedded in Concrete: The Polarization Resistance and AC Impendance Methods”, ASTM STP 906, pp. 43- 63, 1984.
[56]Gonzalez, J.A., “Corrosion of Concrete”, British Corrosion Journal, Vol. 15, No. 3, pp. 135-139, 1980.
[57]Berke, N.S., “Corrosion of Steel in Cracked Concrete”, Corrosion Engineering, Vol. 49, No. 11, pp. 934- 943, 1993.
[58]Dhir, R.K., “Quantifying Chloride Induced Corrosion from Half- Cell Potential”, Cement and Concrete Research, Vol. 23, pp. 1443-1454, 1993.
[59]柯賢文，「腐蝕及其防制」，全華科技圖書有限公司，民國八十四年。
[60]Rodriguez, J., Andrade, C., “Load-Bearing Capacity Loss in Corrosion Structure”, ACI Spring Convention, Toronto Ontario Canada, 1990.
[61]Morris, W., Vico, A., M. Vazquez, S. R. Sanchez, “Corrosion of Reinforcing Steel Evaluated by Means of Concrete Resistivity Measurements”, Elsevier Science Ltd, Corrosion Science, Vol. 44, pp. 81-99, 2002.
[62]Polder, R.B., “Test Methods for on Site Measurement of Resistivity of Concrete - a RILEM TC-154 Technique Recommendation”, Elsevier Science Ltd, Construction and Building Materials, Vol. 15, pp. 125-131, 2001.
[63]Fukushima, T., Yoshizaki, Y., Tomosawa, F., Takahashi, K., “Relationship between neutralization depth and concentration distribution of CaCO3–Ca(OH)2 in carbonated concrete”, V. M. Malhotra (Ed.), Advances in Concrete Technology, ACI SP-179, Tokushima, Japan, pp. 347-363, 1998.
[64]Thomas, M., “Chloride thresholds in marine concrete,” Cement and Concrete Research, vol. 26, on.4, pp.513-519, 1996.
[65]Reou, J.S., Ann, K.Y., “Electrochemical assessment on the corrosion risk of steel embedment in OPC concrete depending on the Corrosion detection techniques.” ,Materials Chemistry and Physics, vol. 113,pp.78-84,2009.
[66]Cheng-Feng Chang, Jing-Wen Chen, “The experimental investigation of concrete carbonation depth”, Cement and Concrete Research, Vol. 36, pp.1760-1767,2006
[67]Jennifer, A.G., Hemant, S.L., Ashok, M.K., “Testing pH of Concre,” Concrete International, 2007.
[68]陳正平，「談海砂屋鑑定」，台灣省土木技師公會技師報，2011。
[69]Glass, G.K., Reddy, B., Buenfeld, N.R., “Corrosion inhibition in concrete arising from its acid neutralization capacity,” Corrosion Science, vol. 42 , pp.1587–1598,2000.
[70]Jung, M.S., Shin, M.C., Ann, K.Y., “Fingerprinting of a concrete mix proportion using the acid neutralisation capacity of concrete matrices,” Construction and Building Materials, vol. 26, pp.65-71, 2012.
[71]Tang, L., Nilsson, L.O., “Chloride binding capacity and binding isotherms of OPC pastes and mortars,” Cement and Concrete Research, vol. 23, pp.247–253, 1993.
[72]Lambert, P., Page, C.L., Short, N.R., “Pore Solution Chemistry of the Hydrated System Tricalcium Silicate/Sodium Chloride/Water,” Cement and Concrete. Research, Vol. 15, pp. 675-680, 1985.
[73]Rasheeduzzafar, Ehtesham, H.S. and Al-Saadoun, S.S., “Effect of Tricalcium Aluminate Content of Cement on Chloride Binding and Corrosion of Reinforcing Steel in Concrete,” ACI Materials Journal, pp. 3-12, January-February 1992.
[74]Dhir, R.K., El-Mohr, M.A.K., Dyer, T.D., “Chloride binding in GGBS concrete,” cement and Concrete Research, vol. 26, no.12, pp.1767-1776, 1996.
[75]Rui, L., Yuebo, C., Changyi, W., Xiaoming, H., “Study of chloride binding and diffusion in GGBS concrete,” Cement and Concrete Research, vol. 33, pp.1-7, 2003.
[76]Angst, U., Elsener, B., Larsen, C.K., Vennesland,Q., “Critical chloride content in reinforced concrete — A review,” Cement and Concrete Research, vol.39, pp.1122-1138, 2009.
[77]Tuutti, K., “Corrosion of Steel in Concrete,” Swedish Cement and Concrete Research Institute, 1982.
[78]Ann, K.Y., Song, H.W., “Chloride threshold level for corrosion of steel in concrete,” corrosion science, vol.49, pp.4113-4133, 2007.
[79]Pengping, L., Jianbo, X., Zhihong, F., Shengnian,W., “Influence of Mineral Admixtures on Chloride Threshold Value for the Corrosion of Steel Reinforcement,” Advanced Materials Research, vol. 335-336 ,pp.1168-1173,2011.