發(fā)布時(shí)間：2018-03-10 07:30

  本文選題：氯鹽環(huán)境　切入點(diǎn)：混凝土　出處：《中國(guó)礦業(yè)大學(xué)》2014年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：氯鹽侵入是導(dǎo)致混凝土結(jié)構(gòu)鋼筋銹蝕的最重要因素之一，能夠及時(shí)、準(zhǔn)確掌握混凝土中氯離子分布狀態(tài)，對(duì)于正確評(píng)價(jià)、預(yù)測(cè)混凝土耐久性和及時(shí)采取措施進(jìn)行維修、維護(hù)可提供重要科學(xué)依據(jù)。本文以氯鹽環(huán)境為背景，以多孔介質(zhì)的傳質(zhì)傳輸基本理論為依據(jù)，采取試驗(yàn)研究和理論分析相結(jié)合的手段，對(duì)氯鹽環(huán)境下混凝土中氯離子含量的無(wú)損檢測(cè)技術(shù)及氯離子含量的在混凝土中分布發(fā)展進(jìn)行了深入的研究。 采用恒電流陽(yáng)極電解法制備氯離子無(wú)損檢測(cè)探針，并對(duì)其極化的最佳條件進(jìn)行研究。結(jié)果表明：最佳極化電流密度為0.4mA/cm2；最佳極化時(shí)間為5.5小時(shí)。 配制不同濃度和化學(xué)成份的氯鹽溶液，系統(tǒng)地研究并檢測(cè)了電解法制備的Ag/AgCl電極在鹽溶液中的能斯特響應(yīng)、電位響應(yīng)時(shí)間特性、溫度響應(yīng)以及電位的重現(xiàn)性和長(zhǎng)期穩(wěn)定性。研究表明：無(wú)論是在NaCl溶液還是在NaCl+SPS溶液中探針電位與溶液的氯離子的濃度都能夠保持較好的線(xiàn)性響應(yīng)關(guān)系，并且擬合精度較高；電位響應(yīng)時(shí)間較短，，為35s；溫度系數(shù)較低，為0.418mV/℃；浸泡在加鹽的混凝土模擬空隙液溶液中探針電位極差的最大值不超過(guò)2mV，平均值極差為2.9mV，探針保持了較好的長(zhǎng)期穩(wěn)定性。 研究了混凝土中氯離子含量的無(wú)損檢測(cè)方法。通過(guò)測(cè)定在不同摻鹽量混凝土試塊由飽水到干燥過(guò)程中Ag/AgCl探針的電位和氯離子的含量，建立了混凝土中氯離子含量和電極電位間的相關(guān)性模型；研究了水灰比和混凝土的齡期對(duì)探針電位的影響，試驗(yàn)表明：在混凝土中氯離子濃度相同的情況下，水灰比越小，探針的電位越大，同種水灰比下，氯離子濃度越大，探針電位越小；混凝土水化前期會(huì)出現(xiàn)電位的極小值，然后逐漸回升，約28d后達(dá)到穩(wěn)定值。 分別建立了模擬海洋和鹽湖環(huán)境系統(tǒng)，應(yīng)用埋入式無(wú)損檢測(cè)探針定期測(cè)定了混凝土試件不同高度、不同深度處的氯離子含量大小，分析了氯鹽環(huán)境下不同暴露條件氯離子在混凝土中的傳輸機(jī)理，并對(duì)氯離子的分布進(jìn)行了預(yù)測(cè)。
[Abstract]:Chloride intrusion is one of the most important factors leading to the corrosion of reinforced bars in concrete structures. It can grasp the distribution of chloride ions in concrete timely and accurately. In order to correctly evaluate, predict the durability of concrete and take timely measures to carry out maintenance, Maintenance can provide an important scientific basis. Based on the background of chloride environment and the basic theory of mass transfer in porous media, this paper adopts the method of combining experimental research with theoretical analysis. The nondestructive detection technology of chloride ion content in concrete under chloride environment and the distribution and development of chloride ion content in concrete were studied in this paper. The chloride ion nondestructive detection probe was prepared by constant current anode electrolysis and the optimum conditions of its polarization were studied. The results show that the optimum polarization current density is 0.4 Ma / cm ~ 2 and the optimum polarization time is 5.5 hours. The characteristics of Nernst response and potential response time of Ag/AgCl electrode prepared by electrolytic method in salt solution were studied and tested systematically by preparing chloride solution with different concentration and chemical composition. The temperature response, the reproducibility and long-term stability of the potential. The results show that both the probe potential in NaCl solution and the concentration of chloride ion in NaCl SPS solution can maintain a good linear response relationship, and the fitting accuracy is high. The potential response time is shorter (35s), the temperature coefficient is low (0.418mV / 鈩

本文編號(hào)：1592341