EXPERIMENTAL RESEARCH ON CHLORIDE THRESHOLD LEVEL OF STEEL CORROSION IN SYNTHETIC PORE SOLUTION UNDER HIGH TEMPERATURE
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摘要: 当钢筋周围混凝土孔隙液的游离Cl-超过临界氯离子浓度(cCl-)时,混凝土结构内的钢筋就会易于腐蚀。所以cCl-是暴露于氯离子环境的混凝土结构寿命预测的一个重要指标。特别在高温地区,钢筋混凝土结构破坏更严重。通过研究高温条件对钢筋腐蚀cCl-的影响。试验在50℃模拟孔隙溶液中进行,采用恒电位方法,考虑不同pH值的影响,得到具有95%保证率的临界氯离子浓度值。试验研究发现,在50℃溶液中钢筋腐蚀临界氯离子浓度比常温(25℃)下得到的结果小得多,而且温度的影响作用随着控制电位的下降和pH值的上升越明显。最后给出了温度与临界氯离子浓度的关系曲线。Abstract: The steel rebar inside reinforced concrete structures is susceptible to corrosion when Cl-content at the surface of the steel exceeding a chloride threshold level(CTL).The CTL is an important influence on the service life of concrete structures exposed to chloride environments.Especially in high temperature regions, reinforced concrete structures are more severely damaged.The paper focused on studying the influence of high temperature on CTL.The experiment was carried out in 50 ℃ synthetic pore solution, considering the influences of electric potentials and pHs, and CTL of 95% acceptance value achieved.Results show that CTL under 50 ℃ is much smaller than that under normal temperature(25 ℃), and the controlling effect of temperature is more obvious as the corrosion potential decreases and pH value increases.Fitting curve of CTL to temperature was also presented.
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? [1] Arup H. The Mechanics of the Protection of Steel by Concrete?[C]∥ Society of Chemical Industrial Conference of Reinforcement?in Concrete Construction,1983. [2] 张誉.混凝土结构耐久性概论[M].上海:上海科学技术出版社,2003. [3] FIB. Model Code for Service Life Design [M]. Bulletin:?Federation International du Beton,2006. [4] Manera M, Vennesland O, Bertolini L. Chloride Threshold for?Rebar Corrosion in Concrete with Addition of Silica Fume [J]. Corrosion Science,2008(50):544-560. [5] Glass G K, Buenfeld N R. Chloride Threshold Level for Corrosion?of Steel in Concrete [J]. Corrosion Science,1997(39):1001-1013. [6] Alonso C , Andrade C , Castellote M, et al. Chloride Threshold?Values to Depassivate Reinforcing Bars Embedded in a?Standardized OPC Mortar [J]. Cement and Concrete Research,2000(30):1047-1055. [7] Broomfield J P. Corrosion of Steel in Concrete: Understanding,?Investigation and Repair [M]. London: E FN Spon,1997. [8] 陈卿.钢筋腐蚀临界氯离子浓度的试验研究[D].上海:上海交通大学,2008. [9] Poursaee A, Hansson C M. Reinforcing Steel Passivation in Mortar?and Pore Solution [J]. Cement Concrete Research,2007,37(7):1127-1133. [10] 陈卿,宋晓冰,翟之阳.混凝土模拟孔隙液中钢筋腐蚀临界氯离子浓度试验研究[J].四川建筑科学研究,2008,34(6):156-162. [11] Izquierdo D. Potentiostatic Determination of Chloride Threshold?Values for Rebar Depassivation: Experimental and Statistical?Study [J]. Electrochimica Acta,2004,49(17/18):2731-2739. [12] Hussain S E, Rasheeduzzafar, Al-Musallam A. Factors Affecting?Threshold Chloride for Reinforcement Corrosion in Concrete [J]. Cement and Concrete Research,1995;25(7):1543-1555. [13] 洪定海.混凝土中钢筋的腐蚀与保护[M].北京:中国铁道出版社,1998.
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