【摘要】：鋼筋混凝土結(jié)構(gòu)是自20世紀(jì)以來使用的最為廣泛的建筑材料之一,鋼筋在混凝土中的耐蝕性是研究人員長期關(guān)注的熱點�；炷林袖摻畹母g主要有兩個原因,混凝土的碳化和氯離子的侵蝕。本文以熱浸鍍Zn-5%Al合金鍍層作為鋼筋的保護(hù)涂層,對其在混凝土中的電化學(xué)腐蝕行為做了研究,并通過將熱浸鍍Zn-5%Al層在混凝土模擬孔隙液和混凝土中的電化學(xué)行為對比,系統(tǒng)地研究了其作為混凝土中鋼筋保護(hù)層的可行性。實驗首先采用Tafel極化測試和電化學(xué)阻抗譜方法,研究了熱浸鍍Zn-5%Al鍍層在混凝土模擬孔隙液中浸泡不同時間的腐蝕行為,探討了腐蝕產(chǎn)物保護(hù)層試樣在混凝土模擬孔隙液中的耐氯離子腐蝕性。研究表明,Zn-5%Al鍍層浸泡15d后自腐蝕電流密度為1.16×10-7A/cm2,接近鋼筋混凝土鈍化臨界值1.00×10-7A/cm2,耐蝕性最佳,對腐蝕產(chǎn)物進(jìn)行SEM形貌分析和EDS成分分析表明此時試樣表面是由片狀的鋅酸鈣(Ca HZn)和團(tuán)絮狀的鋁酸鈣(Ca HAl)組成;腐蝕產(chǎn)物保護(hù)層試樣在0.1mol/L的氯離子混凝土模擬孔隙液中浸泡30d后,自腐蝕電流密度為4.53×10-7A/cm2,耐蝕性優(yōu)異,在1mol/L的氯離子混凝土模擬孔隙液中浸泡30d后,自腐蝕電流密度為3.37×10-6A/cm2,耐蝕性不佳,腐蝕產(chǎn)物保護(hù)層試樣對基體的保護(hù)作用隨著氯離子濃度的升高而降低,腐蝕產(chǎn)物保護(hù)層試樣的氯離子閾值為0.2mol/L。通過干濕循環(huán)加速實驗和恒電流加速腐蝕實驗,使用電化學(xué)阻抗譜方法,研究了熱浸鍍Zn-5%Al鋼筋混凝土的電化學(xué)腐蝕行為。在干濕循環(huán)加速實驗中,混凝土的電阻隨著浸泡時間的延長先變小,然后基本保持不變,腐蝕產(chǎn)物層的電阻隨著浸泡時間的延長逐漸減小,普通鋼筋和熱浸鍍Zn-5%Al鋼筋表面的電荷遷移電阻隨著浸泡時間的延長均逐漸減小,熱浸鍍Zn-5%Al鋼筋的耐蝕性整體上仍然優(yōu)于普通鋼筋;在恒電流加速腐蝕試驗中,混凝土的電阻隨著浸泡時間的延長先增加然后基本保持不變,熱浸鍍Zn-5%Al鋼筋表面腐蝕產(chǎn)物層的電阻及鋼筋表面電荷遷移電阻隨著加速時間的延長先減小,然后基本保持不變;通過恒電流加速腐蝕實驗來研究熱浸鍍Zn-5%Al鋼筋混凝土的耐蝕性與鋼筋在混凝土中的自然腐蝕有較大的差距,通過干濕循環(huán)實驗來研究熱浸鍍Zn-5%Al鋼筋混凝土的耐蝕與實際更相符,更有參考價值。總體上,熱浸鍍Zn-5%Al鍍層作為鋼筋的保護(hù)層能顯著提高普通鋼筋在混凝土中的耐蝕性,但不如熱鍍鋅鋼筋。
[Abstract]:Reinforced concrete structure is one of the most widely used building materials since the 20th century. There are two main reasons for the corrosion of steel bars in concrete, carbonation and chloride ion corrosion. In this paper, the electrochemical corrosion behavior of Zn-5%Al alloy coating in concrete was studied. By comparing the electrochemical behavior of hot-dip Zn-5%Al coating in concrete simulated pore fluid and concrete, the feasibility of using Zn-5%Al coating as the protective layer of steel bar in concrete is systematically studied. The corrosion behavior of hot-dip Zn-5%Al coating immersed in concrete simulated pore solution for different time was studied by Tafel polarization test and electrochemical impedance spectroscopy (EIS). The corrosion resistance of protective layer samples of corrosion products in simulated pore fluid of concrete is discussed. The results show that the corrosion current density of Zn-5%Al coating is 1.16 脳 10 ~ (-7) A / cm ~ (2), close to the critical passivation value of reinforced concrete, 1.00 脳 10 ~ (-7) A / cm ~ (2), and the corrosion resistance is the best. The results of SEM and EDS analysis show that the sample surface is composed of flake calcium zincate (Ca HZn) and flocculent calcium aluminate (Ca HAl). The corrosion product protective layer samples were immersed in the chloride ion concrete simulated pore fluid of 0.1mol/L for 30 days, the corrosion current density was 4.53 脳 10 ~ (-7) A / cm ~ (2), and the corrosion resistance was excellent. The sample was soaked in the chloride ion concrete simulated pore fluid of 1mol/L for 30 days. The self-corrosion current density is 3.37 脳 10 ~ (-6) A / cm ~ (2) and the corrosion resistance is poor. The protective effect of the corrosion product protective layer on the substrate decreases with the increase of chloride ion concentration, and the chloride ion threshold of the corrosion product protection layer sample is 0.2 mol / L. The electrochemical corrosion behavior of hot-dip Zn-5%Al reinforced concrete was studied by means of accelerated dry and wet cycle test and constant current accelerated corrosion test. The electrochemical impedance spectroscopy (EIS) method was used to study the electrochemical corrosion behavior of hot-dip Zn-5%Al reinforced concrete. In the accelerated test of wet and dry cycle, the resistance of concrete decreases with the time of soaking, and then remains unchanged, and the resistance of the corrosion product layer decreases gradually with the prolongation of soaking time. The charge transfer resistance on the surface of ordinary steel bar and hot-dip Zn-5%Al steel bar decreases gradually with the prolongation of soaking time, and the corrosion resistance of hot-dip Zn-5%Al steel bar is still better than that of ordinary steel bar as a whole. In the constant current accelerated corrosion test, the resistance of concrete increases first with the prolongation of immersion time and then remains basically unchanged. The resistance of corrosion product layer and charge transfer resistance of hot-dip Zn-5%Al steel first decrease with the increase of acceleration time, and then remain unchanged. The corrosion resistance of hot-dip Zn-5%Al reinforced concrete is studied by constant current accelerated corrosion test, which is different from the natural corrosion of steel bar in concrete. The study on corrosion resistance of hot-dip Zn-5%Al reinforced concrete by dry and wet cycle experiment is more consistent with the practice and has more reference value. As a whole, hot-dip Zn-5%Al coating as the protective layer of steel bar can significantly improve the corrosion resistance of ordinary steel bar in concrete, but it is not as good as hot-dip galvanized steel bar.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG174.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳錦虹,周明君,盧錦堂,許喬瑜,孔綱,眭潤舟;熱浸鍍鋅鋼筋在混凝土中的應(yīng)用前景[J];材料保護(hù);2003年09期

2 盧錦堂;陳九龍;孔綱;;熱鍍鋅層在不同pH值的飽和Ca(OH)_2溶液中的腐蝕行為[J];材料保護(hù);2010年05期

3 王大強(qiáng);劉曉麗;汪輝;畢巧巍;;纖維筋與高強(qiáng)纖維混凝土的粘結(jié)性能[J];低溫建筑技術(shù);2011年06期

4 許清風(fēng),蔣永生;影響環(huán)氧涂層鋼筋粘結(jié)錨固性能的因素分析[J];工業(yè)建筑;1999年06期

5 ;Corrosion Evolution of Reinforcing Steel in Concrete under Dry/Wet Cyclic Conditions Contaminated with Chloride[J];Journal of Materials Science & Technology;2012年10期

6 李志國;試論鹽及溶液對混凝土及鋼筋混凝土的破壞[J];混凝土;1995年02期

7 肖佳;勾成福;;混凝土碳化研究綜述[J];混凝土;2010年01期

8 貝志君;Zn—5Al—RE合金鍍層的金相觀察[J];金屬制品;1992年03期

9 許賢敏;國外不銹鋼筋的研究動態(tài)[J];山東建材;2000年05期

10 金偉良,趙羽習(xí);混凝土結(jié)構(gòu)耐久性研究的回顧與展望[J];浙江大學(xué)學(xué)報(工學(xué)版);2002年04期

相關(guān)博士學(xué)位論文 前3條

1 胡融剛;鋼筋/混凝土體系腐蝕過程的電化學(xué)研究[D];廈門大學(xué);2004年

2 張杰;熱浸鍍鋅及其合金海水中腐蝕行為研究[D];中國科學(xué)院研究生院（海洋研究所）;2005年

3 徐港;銹蝕鋼筋混凝土粘結(jié)錨固性能研究[D];華中科技大學(xué);2007年

相關(guān)碩士學(xué)位論文 前3條

1 肖小瓊;銹蝕鋼筋混凝土粘結(jié)性能試驗研究[D];中南大學(xué);2011年

2 譚東陽;銹蝕鋼筋混凝土粘結(jié)性能試驗研究[D];重慶大學(xué);2012年

3 陳貞萍;鋼筋表面鋅鋁鍍層及其與環(huán)氧樹脂粘附性研究[D];華南理工大學(xué);2014年

，

本文編號：2364252