Beton karışım suyu ve boşluk suyuna katılan ekolojik inhibitörlerin donatı korozyonuna etkisinin araştırılması
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Dosyalar
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Korozyon, betonarme yapıların en büyük sorunudur. Korozyonu önlemek için çimentoya organik ve inorganik inhibitörler eklenir. Günümüzde bazı inorganik ve organik bileşiklerin toksisitesi nedeniyle, doğal inhibitörlerin kullanımına daha fazla dikkat edilmektedir. Bu çalışmanın amacı; 2 saat, 7, 28, 56 ve 90 gün süreyle beton karışım suyu ve beton boşluk suyuna maruz kalan donatı çeliklerinin korozyon mekanizmasını araştırmaktır. Karışım suyu ve boşluk suyu çözeltilerindeki donatıların korozyon direnci; Dinamik Elektrokimyasal Empedans Spektroskopisi (DEIS), Elektrokimyasal Empedans Spektroskopisi (EIS) ve Tafel Ekstrapolasyon (TP) yöntemleri kullanılarak belirlenmiştir. Ayrıca belirtilen ortam ve koşullara maruz bırakılan donatıların korozyon direncini arttırmak amacıyla ekolojik inhibitörler (50 ppm kafein ve 50 ppm L-arjinin) kullanılmıştır. Elektrokimyasal deneyler sonrası metal yüzeyinde meydana gelen değişimler Taramalı Elektron Mikroskobu (SEM), Enerji Dağılımlı X-Ray Spektroskopisi (EDS), Atomik Kuvvet Mikroskobu (AFM) ve Optik Profilometre (OP) analizleri ile incelenmiş, uygulanan tüm yöntemlerle aralarındaki korelasyon ortaya konulmuştur. Bunlara ek olarak referans ve inhibitör ikameli çimentolar için TS-EN 196-1'e göre 2, 7, 28 günlük standart çimento deneyleri yapılarak basınç dayanımları tespit edilmiştir. Kritik süre olan 28. gündeki numunelerin hidratasyon gelişiminde meydana gelen değişimler SEM, Diferansiyel Termal Analizi (DTA), Termogravimetrik Analiz (TGA), X-Işını Difraksiyonu (XRD) ve Fourier Dönüşümlü Kızılötesi Spektrometresi (FT-IR) analiz teknikleri kullanılarak incelenmiştir. Elde edilen sonuçlara göre, donatı çeliğinin çözeltide bekleme süresi arttıkça korozyon direncinin de arttığı gözlenmiştir. Ayrıca donatı çeliğinin boşluk suyu çözeltisindeki korozyon direncinin karışım suyundan daha iyi olduğu belirlenmiştir. Bekleme süresiyle paralel olarak kullanılan inhibitörlerin donatının korozyon direncini arttırıcı yönde etki ettiği ve L-arjininin kafeine göre daha yüksek inhibisyon etkisi gösterdiği tespit edilmiştir. 75 ppm kafein ve L-arjinin içeren harçların basınç dayanımı 28. günde tüm çimento harçlarından daha yüksek dayanım göstermiştir. Kullanılan her iki inhibitörün de çimento hidratasyonuna katkı sağladığı ve korozyon inhibitörü olarak boşluk suyu ve karışım suyu ortamlarında kullanılabileceği bu tez çalışması ile bilimsel olarak ispatlanmıştır.
Corrosion is the biggest problem of reinforced concrete structures. Organic and inorganic inhibitors are added to the cement to prevent corrosion. Today, due to the toxicity of some inorganic and organic compounds, more attention is paid to the use of natural inhibitors. The aim of this study; To investigate the corrosion mechanism of reinforcement steels exposed to concrete mixing water and concrete pore solution for 2 hours, 7, 28, 56 and 90 days. Corrosion resistance of reinforcement in mixing water and concrete pore solution was determined using Dynamic Electrochemical Impedance Spectroscopy (DEIS), Electrochemical Impedance Spectroscopy (EIS) and Tafel Extrapolation (TP) methods. In addition, ecological inhibitors (50 ppm caffeine and 50 ppm L-Arginine) have been used to increase the corrosion resistance of the steels exposed to the specified environment and conditions. The changes on the metal surface after electrochemical experiments were examined by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM) and Optical Profilometer (OP) analysis, and the correlation between them was revealed with all the methods applied. In addition to these, compressive strengths of reference and inhibitor added cement pastes were determined for 2, 7 and 28 days according to TS-EN 196-1. Changes in the hydration mechanism of samples on the 28th day, which is critical period, were examined using SEM, Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analysis techniques. According to the obtained results, it was observed that the corrosion resistance of reinforcement steel increased with the waiting time of the solution. It has also been determined that the corrosion resistance of the reinforcement steel in the concrete pore solution is higher than the mixing water. It was determined that the inhibitors used had an effect on increasing the corrosion resistance of the reinforcement steel in parallel with the waiting time and L-arginine had a higher inhibition effect than caffeine. The compressive strength of mortars containing 75 ppm caffeine and L-arginine showed higher strength than all the cement mortars on the 28th day. It has been scientifically proven that the inhibitors used to contribute to the cement hydration can also be used as a corrosion inhibitor in concrete pore solution and mixing water mediums.
Corrosion is the biggest problem of reinforced concrete structures. Organic and inorganic inhibitors are added to the cement to prevent corrosion. Today, due to the toxicity of some inorganic and organic compounds, more attention is paid to the use of natural inhibitors. The aim of this study; To investigate the corrosion mechanism of reinforcement steels exposed to concrete mixing water and concrete pore solution for 2 hours, 7, 28, 56 and 90 days. Corrosion resistance of reinforcement in mixing water and concrete pore solution was determined using Dynamic Electrochemical Impedance Spectroscopy (DEIS), Electrochemical Impedance Spectroscopy (EIS) and Tafel Extrapolation (TP) methods. In addition, ecological inhibitors (50 ppm caffeine and 50 ppm L-Arginine) have been used to increase the corrosion resistance of the steels exposed to the specified environment and conditions. The changes on the metal surface after electrochemical experiments were examined by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM) and Optical Profilometer (OP) analysis, and the correlation between them was revealed with all the methods applied. In addition to these, compressive strengths of reference and inhibitor added cement pastes were determined for 2, 7 and 28 days according to TS-EN 196-1. Changes in the hydration mechanism of samples on the 28th day, which is critical period, were examined using SEM, Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analysis techniques. According to the obtained results, it was observed that the corrosion resistance of reinforcement steel increased with the waiting time of the solution. It has also been determined that the corrosion resistance of the reinforcement steel in the concrete pore solution is higher than the mixing water. It was determined that the inhibitors used had an effect on increasing the corrosion resistance of the reinforcement steel in parallel with the waiting time and L-arginine had a higher inhibition effect than caffeine. The compressive strength of mortars containing 75 ppm caffeine and L-arginine showed higher strength than all the cement mortars on the 28th day. It has been scientifically proven that the inhibitors used to contribute to the cement hydration can also be used as a corrosion inhibitor in concrete pore solution and mixing water mediums.
Açıklama
YÖK Tez No: 633631
Anahtar Kelimeler
İnşaat Mühendisliği, Civil Engineering, Donatı korozyonu, Reinforcement corrosion, Kimyasal inhibitör, Chemical inhibitor, Portland çimentosu, Portland cement
