本文選題：電化學(xué)方法 + 加速銹蝕��； 參考：《青島理工大學(xué)》2013年碩士論文

【摘要】：鋼筋混凝土是當(dāng)今世界使用最廣泛的工程材料。海水、鹽霧及除冰鹽中氯離子滲透到混凝土內(nèi)部導(dǎo)致鋼筋銹蝕是威脅混凝土耐久性的最主要原因�？紤]海水中存在氯離子、硫酸根離子等多重腐蝕離子，混凝土結(jié)構(gòu)在服役過(guò)程中承受一定的荷載作用。本文采用浸泡腐蝕、恒電位加速腐蝕以及電化學(xué)特性研究等試驗(yàn)方法，系統(tǒng)研究鋼筋、鋼筋混凝土在多重腐蝕離子、荷載-腐蝕耦合作用下的腐蝕損傷行為。研究主要結(jié)論如下： （1）采用不同濃度氯鹽溶液、硫酸鹽溶液，氯鹽和硫酸鹽復(fù)合溶液，不同PH值下的氯鹽溶液作為模擬溶液，研究鋼筋在上述腐蝕溶液中的電化學(xué)行為。結(jié)果表明：隨著氯離子濃度增加，極化電阻隨之降低，腐蝕電流密度隨之增加，鋼筋銹蝕臨界氯離子濃度為0.05mol/L；溶液pH值越小，鋼筋銹蝕臨界氯離子濃度相應(yīng)降低；溶液中硫酸根離子的存在，減緩了鋼筋的銹蝕，且減緩作用隨硫酸根離子濃度增加而增強(qiáng)。 （2）通過(guò)對(duì)3組（4種粉煤灰摻量、5種礦粉摻量、10種腐蝕溶液）鋼筋混凝土試件進(jìn)行電化學(xué)加速銹蝕試驗(yàn)，研究鋼筋混凝土銹裂損傷形態(tài)及其規(guī)律。結(jié)果表明：鋼筋腐蝕電流強(qiáng)度隨時(shí)間增加而下降，混凝土裂縫寬度隨通電時(shí)長(zhǎng)增加而呈二次函數(shù)關(guān)系增加，裂縫寬度隨電流強(qiáng)度下降而線(xiàn)性增加。混凝土初裂時(shí)間和達(dá)到0.2mm裂縫寬度時(shí)間隨粉煤灰和礦粉摻量增加而增加；當(dāng)粉煤灰、礦粉摻量為15%時(shí)，混凝土中鋼筋銹蝕率最小；內(nèi)摻腐蝕溶液對(duì)混凝土的初裂縫的影響主要體現(xiàn)在復(fù)合溶液的促進(jìn)和減緩雙重作用。 （3）采用四點(diǎn)彎曲加載方法，對(duì)兩種配合比混凝土施加不同等級(jí)荷載后，浸泡于氯鹽、氯鹽和硫酸鹽復(fù)合溶液7個(gè)月，研究混凝土中氯離子傳輸規(guī)律。結(jié)果表明：彎曲荷載作用下混凝土中氯離子濃度隨深度增加而減少，達(dá)到一定深度處趨于穩(wěn)定。復(fù)合溶液中硫酸根離子與水化鋁酸鈣反應(yīng)生成鈣礬石，，填充了混凝土的孔隙，延緩了混凝土中氯離子傳輸。隨荷載等級(jí)增加，受拉區(qū)混凝土中氯離子傳輸速度相應(yīng)增加。 （4）采用四點(diǎn)彎曲和電化學(xué)加速銹蝕試驗(yàn)方法，研究未摻礦物摻合料、雙摻礦物摻合料鋼筋混凝土中鋼筋銹蝕及其氯離子遷移規(guī)律。試驗(yàn)表明：加載30%時(shí)，混凝土受力區(qū)的的初始電流值為受拉區(qū)＞受壓區(qū)＞未加載區(qū)，且電流強(qiáng)度隨著時(shí)間增加而減小。受拉區(qū)的氯離子含量、銹蝕率大于其他受力區(qū)。混凝土中鋼筋的初始電流值、受拉區(qū)銹蝕率隨著荷載等級(jí)增加而增加，加載50%時(shí)，前期受力區(qū)裂縫開(kāi)裂較慢，后期隨著鋼筋銹蝕開(kāi)裂速度迅速。未摻礦物摻合料混凝土中鋼筋的初始電流值大于雙摻礦物摻合料混凝土中鋼筋的初始電流值，但雙摻礦物摻合料混凝土中鋼筋的銹蝕率高，銹蝕嚴(yán)重。
[Abstract]:Reinforced concrete is the most widely used engineering material in the world. The corrosion of steel bar caused by chloride in seawater, salt spray and deicing salt is the main reason that threatens the durability of concrete. Considering the presence of chloride ions and sulfate ions in seawater, concrete structures are subjected to certain loads. In this paper, immersion corrosion, potentiostatic accelerated corrosion and electrochemical characteristics are used to systematically study the corrosion damage behavior of steel bar and reinforced concrete under the action of multiple corrosion ions and load-corrosion coupling. The main conclusions are as follows: (1) different concentrations of chloride solution, sulfate solution, chloride and sulfate complex solution, different PH value of chloride solution as simulation solution, The electrochemical behavior of steel bars in the above corrosion solution was studied. The results show that with the increase of chloride concentration, the polarization resistance decreases and the corrosion current density increases. The critical chloride ion concentration of steel bar corrosion is 0.05 mol / L, and the lower the pH value of the solution is, the lower the corrosion critical chloride ion concentration is. The presence of sulfate ions in the solution slows the corrosion of steel bars. The mitigation effect was enhanced with the increase of sulfate ion concentration. (2) the electrochemical accelerated corrosion test was carried out on three groups of reinforced concrete specimens (4 kinds of fly ash and 5 kinds of mineral powder and 10 kinds of corrosion solution). The rust-cracking damage pattern and its regularity of reinforced concrete are studied. The results show that the corrosion current strength of steel bar decreases with the increase of time, the crack width of concrete increases in a quadratic function with the increase of the current duration, and the crack width increases linearly with the decrease of the current intensity. The initial crack time of concrete and the time to reach 0.2mm crack width increase with the increase of fly ash and mineral powder content, when the content of fly ash and mineral powder is 15, the corrosion rate of steel bar in concrete is the least. The effect of corrosion solution on the initial crack of concrete is mainly reflected in the dual effect of the compound solution. (3) after applying the different grade load to the two kinds of concrete, the method of four-point bending loading is adopted. The chloride ion transport in concrete was studied by immersing in chloride salt, chloride salt and sulfate compound solution for 7 months. The results show that the concentration of chloride in concrete decreases with the increase of depth and tends to be stable at a certain depth under bending load. Ettringite was formed by the reaction of sulfate ion with calcium aluminate hydrate in composite solution, which filled the pores of concrete and delayed the chloride ion transport in concrete. With the increase of load grade, the rate of chloride ion transport in the concrete in tension zone increases accordingly. (4) by means of four-point bending and electrochemical accelerated corrosion test, the mineral admixture is studied. Corrosion of steel bars and chloride ion migration in reinforced concrete with double mineral admixtures. The experimental results show that the initial current value of the concrete under loading is the tensile zone > the compression zone > the unloaded zone, and the current intensity decreases with the increase of time. The chloride content and corrosion rate in the tensile zone are higher than those in the other stress regions. The initial current value of steel bar in concrete, the corrosion rate of tensile zone increases with the increase of load grade. When the load is 50%, the crack cracking in the early stress zone is slower, and the corrosion crack rate in the later stage is rapid with the reinforcement corrosion rate. The initial current value of steel bar in concrete without mineral admixture is higher than that in concrete with double mineral admixture, but the corrosion rate of steel bar in concrete with mineral admixture is high and corrosion is serious.
【學(xué)位授予單位】：青島理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類(lèi)號(hào)】：TU528.571

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳惠玲;李曉娟;魏雨;;碳鋼在含氯離子環(huán)境中腐蝕機(jī)理的研究[J];腐蝕與防護(hù);2007年01期

2 孫勇志;鋼筋混凝土結(jié)構(gòu)內(nèi)的鋼筋腐蝕監(jiān)測(cè)[J];貴州水力發(fā)電;1999年02期

3 洪乃豐;混凝土中鋼筋腐蝕與防護(hù)技術(shù)(1)——鋼筋腐蝕危害與對(duì)混凝土的破壞作用[J];工業(yè)建筑;1999年08期

4 馮乃謙;日本混凝土耐久性問(wèn)題的歷史發(fā)展及其對(duì)策[J];混凝土;2003年07期

5 金祖權(quán),孫偉,張?jiān)粕?劉志勇;荷載作用下混凝土的碳化深度[J];建筑材料學(xué)報(bào);2005年02期

6 李家康;混凝土結(jié)構(gòu)的裂縫與鋼筋腐蝕[J];青島建筑工程學(xué)院學(xué)報(bào);1997年04期

7 夏寧,于孝民,任青文;混凝土結(jié)構(gòu)耐久性研究現(xiàn)狀[J];水利水電科技進(jìn)展;2005年04期

8 涂啟華;王勝年;潘德強(qiáng);黃君哲;;基于耐久性壽命預(yù)測(cè)的海工混凝土結(jié)構(gòu)檢測(cè)評(píng)估[J];水運(yùn)工程;2008年12期

9 劉曉敏,史志明,許剛,林海潮,宋光鈴,曹楚南;硫酸鹽和溫度對(duì)鋼筋腐蝕行為的影響[J];中國(guó)腐蝕與防護(hù)學(xué)報(bào);1999年01期

10 魏姍;楊峻熙;陶時(shí)新;徐劍;艾輝;彭素姣;;鋼筋阻銹劑的阻銹機(jī)理,發(fā)展和應(yīng)用[J];科技咨詢(xún)導(dǎo)報(bào);2007年10期

相關(guān)碩士學(xué)位論文 前2條

1 莊其昌;裂縫對(duì)海工混凝土耐久性影響研究[D];青島理工大學(xué);2010年

2 岳建彬;鋼筋混凝土結(jié)構(gòu)中銹蝕鋼筋性能退化規(guī)律研究[D];長(zhǎng)沙理工大學(xué);2007年

本文編號(hào)：2076279