Investigation of Structural Behavior of Full-Scale Reinforced Concrete Columns Subjected to Corrosion under Monotonic Loading Effect: Suggestions for Corrosion Studies

Öz

The estimation of the seismic performance of reinforced concrete structures exposed to corrosion is more difficult than uncorroded structures. By this experimental study, it was aimed to keep light on the studies to be done on the reinforced concrete members exposed to corrosion. Five full-scale reinforced concrete columns were corroded for different corrosion levels by using the accelerated corrosion method. The corroded reinforced concrete columns were subjected to monotonic loading under constant axial load and, their yield and ultimate loads, ductility ratios and energy absorption capacities were obtained by experimentally. The actual corrosion levels in the reinforced concrete columns were obtained by breaking the reinforced concrete columns after the loading tests and extracting all embedded reinforced concrete bars from the concrete. As a result of this experimental study, the weaknesses of monotonic loading compared to reversed-cyclic loading were evaluated for considered earthquake indicators. Based on the obtained experimental test results, important recommendations were suggested for further corrosion studies. Within the scope of this study, the ductility ratios and energy dissipation capacities of corroded reinforced concrete columns were decreased as the corrosion levels were increased under the influence of monotonic loading. The confinement effect up to a certain value of corrosion levels and regarding with increasing in earthquake indicator could not been clearly observed under the influence of monotonic loading. Two empirical models to predict the ductility ratios and energy dissipation capacities were developed to be used for seismic assessment of corroded reinforced concrete columns considering the unilateral failure mode.

Anahtar Kelimeler

• Corrosion,Column,Reinforcement bar,Monotonic loading

Paslanmaya Maruz Kalmış Tam Ölçekli Betonarme Kolonların Monotonik Yükleme Etkisi Altında Yapısal Davranışlarının İncelenmesi: Korozyon Çalışmaları İçin Öneriler

Öz

Korozyona maruz kalmış betonarme yapıların sismik performanslarının tahmin edilmesi korozyona uğramamış yapılara göre daha zordur. Gerçekleştirilen bu deneysel çalışma ile birlikte korozyona maruz kalmış betonarme elemanları üzerine yapılacak olan çalışmalara ışık tutulması amaçlanmıştır. Beş adet tam ölçekli betonarme kolonu hızlandırılmış korozyon yöntemi kullanılarak farklı korozyon oranları için paslandırılmıştır. Paslandırılmış betonarme kolonları sabit eksenel yük altında monotonik yüklemeye tabi tutularak, akma ve nihai yükleri, süneklik oranları ve enerji yutma kapasiteleri deneysel olarak elde edilmiştir. Betonarme kolonlarındaki gerçek korozyon oranları yükleme deneylerinden sonra betonarme kolonlarının kırılarak ve gömülü olan tüm betonarme donatılarının çıkartılması ile elde edilmiştir. Yapılan deneysel çalışma sonucunda, monotonik yüklemenin tersinir-tekrarlanır yüklemeye göre zayıf yönleri göz önüne alınan deprem indeksleri açısından değerlendirilmiştir. Elde edilen deneysel sonuçlar doğrultusunda ileriki korozyon çalışmaları için önemli önerilerde bulunulmuştur. Gerçekleştirilen bu çalışma kapsamında, paslanmış betonarme kolonlarının monotonik yükleme etkisi altında süneklik oranları ve enerji yutma kapasiteleri artan korozyon oranına bağlı olarak azalmıştır. Monotonik yükleme etkisi altında pasın belirli oranlarına kadar sağlamış olduğu sargı etkisi ve buna bağlı olarak deprem indekslerindeki artışlar net bir şekilde görülememiştir. Tek doğrultuda göçme modu kabulü ile yapılacak olan sismik değerlendirmelerde kullanılmak üzere paslanmış betonarme kolonların süneklik ve enerji yutma kapasitelerinin tahmin edilebilmesi için iki ampirik model geliştirilmiştir.

Anahtar Kelimeler

• Korozyon,Betonarme donatısı,Kolon,Monotonik yükleme

Kaynakça

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