The aging building stock is turning to be an urging problem for Europe, and it costs even human l... more The aging building stock is turning to be an urging problem for Europe, and it costs even human lives in some cases. Significant part of this building stock along with infrastructure were constructed with substandard characteristics such as poor-quality material, insufficient flexural strength, wrong reinforcement details and improper design of structural system. On the other hand, Europe has highly seismically active zones where devastations are inevitable after even moderate earthquakes. In the light of these facts, countless structures are in need of retrofitting, particularly in seismic areas, while high costs, disturbance to occupants, historical heritage and environmental restrictions are major obstacles for retrofit interventions. Many substandard reinforced concrete (RC) and masonry structures should be seismically retrofitted to reduce their vulnerabilities against earthquakes. Financial constraints, disturbance to the occupants and disruption of functions of the structures are the main obstacles for proper seismic retrofitting of these substandard existing structures. Traditional retrofitting methods such as concrete and steel jacketing, are not applicable in many cases due to high disturbance to occupants and long duration of retrofitting, which may be very critical for commercial, industrial and public buildings. Besides, these methods are also not preferred for historic structures due to the incompatibility of the concrete with traditional lime-based mortars (e.g. Roman cement) and the heavy visible impact to the architectural design. In the last two decades, use of fiber reinforced polymers (FRP) in construction industry has become quite common. Academic researches go back even a decade earlier. FRPs offer practical and innovative solutions for seismic retrofitting due to their lightweight, high tensile strength and noncorrosive character. Besides, the disturbance to the architectural design of the structures are quite limited when they are retrofitted with FRPs. This opens new possibilities for masonry buildings and historic structures belonging cultural heritage.
Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (Ph.D.) -- İst... more Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2016Dünya üzerindeki yapı stoğunun önemli bir bölümü ikinci dünya savaşının büyük yıkımı sonrasında, acil ihtiyaçlar göz önünde bulundurularak hızlı bir şekilde ve son derece kısıtlı maddi imkanlar ile inşaa edilmiştir. Bu yapıların bir çoğunun inşaası sırasında kendi dönemlerine ait inşaat yönetmelikleri gözetilmemiş, eksik ve/veya yanlış detaylarla yapım gerçekleştirilmiştir. Gelişmiş ülkelerde savaş sonrasında inşaat sektöründe bu olumsuzluklar yaşanırken gelişmemiş ülkelerde ise savaşın getirdiği ekonomik yıkım büyük iç ve dış göçleri tetiklemiş ve bu da şehirlerde çarpık yapılaşmayı kontrol edilemez boyutlara taşımıştır. Çarpık yapılaşma doğal olarak beraberinde yapı yönetmeliklerine uymayan, son derece düşük malzeme ve işçilik kalitesine sahip devasa bir yapı stoğunu oluşturmuştur. Sismik olarak aktif olmayan bölgeler...
Reinforcement corrosion is the risk most frequently cited to justify concrete durability research... more Reinforcement corrosion is the risk most frequently cited to justify concrete durability research, especially where it is induced by chlorides. Surface-applied corrosion inhibitors are widely used to mitigate the corrosion process both for carbonation and chlorides of steel reinforcement in concrete. They are applied onto the surface of hardened concrete and penetrate towards steel reinforcement. This paper discusses the corrosion inhibition performance of a new generation of a dual-phase surface-applied corrosion inhibitor (DP-SACI), and its efficiency in corrosion induced by chlorides over 3% referred to cement mass, and also in pre- and post-cracked structures. This corrosion mitigation activity was evaluated onsite for almost four years, in a sea wall exposed to XS1 ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resist...
Reinforcement corrosion is the risk most frequently cited to justify concrete durability research... more Reinforcement corrosion is the risk most frequently cited to justify concrete durability research, especially where it is induced by chlorides. Surface-applied corrosion inhibitors are widely used to mitigate the corrosion process both for carbonation and chlorides of steel reinforcement in concrete. They are applied onto the surface of hardened concrete and penetrate towards steel reinforcement. This paper discusses the corrosion inhibition performance of a new generation of a dual-phase surface-applied corrosion inhibitor (DP-SACI), and its efficiency in corrosion induced by chlorides over 3% referred to cement mass, and also in pre- and post-cracked structures. This corrosion mitigation activity was evaluated onsite for almost four years, in a sea wall exposed to XS1 ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resistance measurements). All of these electrochemical parameters provide accurate information for on-site structures about the efficiency over the time of surface-applied corrosion inhibitors. The effectiveness of the dual-phase surface-applied corrosion inhibitor proved to be up to 99%, even with ongoing corrosion and 0.3 mm cracks near the rebar. The use of DP-SACI provides a non-destructive repair method that inhibits the corrosion process and increases the service life of the element.
1st Croatian Conference on Earthquake Engineering, 2021
The aging building stock is turning to be an urging problem for Europe, and it costs even human l... more The aging building stock is turning to be an urging problem for Europe, and it costs even human lives in some cases. Significant part of this building stock along with infrastructure were constructed with substandard characteristics such as poor-quality material, insufficient flexural strength, wrong reinforcement details and improper design of structural system. On the other hand, Europe has highly seismically active zones where devastations are inevitable after even moderate earthquakes. In the light of these facts, countless structures are in need of retrofitting, particularly in seismic areas, while high costs, disturbance to occupants, historical heritage and environmental restrictions are major obstacles for retrofit interventions. Many substandard reinforced concrete (RC) and masonry structures should be seismically retrofitted to reduce their vulnerabilities against earthquakes. Financial constraints, disturbance to the occupants and disruption of functions of the structures are the main obstacles for proper seismic retrofitting of these substandard existing structures. Traditional retrofitting methods such as concrete and steel jacketing, are not applicable in many cases due to high disturbance to occupants and long duration of retrofitting, which may be very critical for commercial, industrial and public buildings. Besides, these methods are also not preferred for historic structures due to the incompatibility of the concrete with traditional lime-based mortars (e.g. Roman cement) and the heavy visible impact to the architectural design. In the last two decades, use of fiber reinforced polymers (FRP) in construction industry has become quite common. Academic researches go back even a decade earlier. FRPs offer practical and innovative solutions for seismic retrofitting due to their lightweight, high tensile strength and noncorrosive character. Besides, the disturbance to the architectural design of the structures are quite limited when they are retrofitted with FRPs. This opens new possibilities for masonry buildings and historic structures belonging cultural heritage.
In this experimental study, deformed bars were chemically anchored in low strength concrete and p... more In this experimental study, deformed bars were chemically anchored in low strength concrete and pull-out tests were carried out using a specially designed test setup, which allowed cone type concrete failure. The effects of several parameters, such as the depth of drilling holes, types of adhesives and surface condition of concrete in the hole, on pull-out behavior were investigated. For anchoring deformed bars in concrete, four different types of adhesives were used. The depth of the drilling holes varied between six to twelve times the bar diameter. The other test parameters were the humidity and dust condition of the concrete surface in the drilling hole. The experimental results are presented using bond strengths, bond stress-slip relationships and failure patterns.
In Turkey many existing reinforced concrete structures do not have sufficient seismic safety and ... more In Turkey many existing reinforced concrete structures do not have sufficient seismic safety and should be retrofitted. Adhesive anchors are widely used in seismic retrofit applications. To safely design such anchors, it is very important to understand their behavior under pullout forces. In this study, some of the variables, which could affect the anchor behavior such as adhesive type, anchor depth, diameter of the anchor bar and the compression strength of the base member are investigated under pullout forces. A total of 24 specimens were tested to determine their pullout characteristics, load-displacement behaviors, mode of failures and anchorage strengths. The anchor bars of 16 and 20 mm diameters were set in low strength concrete blocks (12 MPa, 16 MPa), for representing the concrete strengths of existing buildings in Turkey. Two different types of adhesives were used. The test setup was designed to allow concrete cone failure. The test results showed that the pullout capacitie...
Many existing reinforced concrete structures were constructed with substandard
characteristics. L... more Many existing reinforced concrete structures were constructed with substandard characteristics. Low quality concrete, poor transverse reinforcement details and insufficient flexural strength are among the most common deficiencies. While substandard structures are in need of retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants are major obstacles for retrofit interventions. Fiber reinforced polymers can provide feasible retrofit solutions with minimum disturbance to occupants. In this study, the basic aim is to investigate the flexural seismic performance of substandard reinforced concrete columns retrofitted with embedded longitudinal fiber reinforced polymer reinforcement without increasing the original dimensions of the columns. In the experimental study, the reference and retrofitted columns were tested under constant vertical and reversed cyclic lateral loads. Three different connection methods of aramid fiber reinforced polymer reinforcement to the footing were investigated experimentally. A significant enhancement was obtained in lateral flexural strength through the proposed retrofitting method. Furthermore, it was observed that the cyclic lateral drift capacities of the retrofitted columns were as high as 3%, which can be deemed as quite satisfactory against seismic actions. The comparison of the experimental data with analytical calculations revealed that a conventional design approach assuming composite action between concrete and fiber reinforced polymer reinforcement can be used for flexural retrofit design. Experimental results also demonstrated that strain limit for longitudinal fiber reinforced polymer (FRP) reinforcement should be remarkably lower in case of reversed cyclic loading conditions.
The aging building stock is turning to be an urging problem for Europe, and it costs even human l... more The aging building stock is turning to be an urging problem for Europe, and it costs even human lives in some cases. Significant part of this building stock along with infrastructure were constructed with substandard characteristics such as poor-quality material, insufficient flexural strength, wrong reinforcement details and improper design of structural system. On the other hand, Europe has highly seismically active zones where devastations are inevitable after even moderate earthquakes. In the light of these facts, countless structures are in need of retrofitting, particularly in seismic areas, while high costs, disturbance to occupants, historical heritage and environmental restrictions are major obstacles for retrofit interventions. Many substandard reinforced concrete (RC) and masonry structures should be seismically retrofitted to reduce their vulnerabilities against earthquakes. Financial constraints, disturbance to the occupants and disruption of functions of the structures are the main obstacles for proper seismic retrofitting of these substandard existing structures. Traditional retrofitting methods such as concrete and steel jacketing, are not applicable in many cases due to high disturbance to occupants and long duration of retrofitting, which may be very critical for commercial, industrial and public buildings. Besides, these methods are also not preferred for historic structures due to the incompatibility of the concrete with traditional lime-based mortars (e.g. Roman cement) and the heavy visible impact to the architectural design. In the last two decades, use of fiber reinforced polymers (FRP) in construction industry has become quite common. Academic researches go back even a decade earlier. FRPs offer practical and innovative solutions for seismic retrofitting due to their lightweight, high tensile strength and noncorrosive character. Besides, the disturbance to the architectural design of the structures are quite limited when they are retrofitted with FRPs. This opens new possibilities for masonry buildings and historic structures belonging cultural heritage.
Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (Ph.D.) -- İst... more Tez (Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016Thesis (Ph.D.) -- İstanbul Technical University, Institute of Science and Technology, 2016Dünya üzerindeki yapı stoğunun önemli bir bölümü ikinci dünya savaşının büyük yıkımı sonrasında, acil ihtiyaçlar göz önünde bulundurularak hızlı bir şekilde ve son derece kısıtlı maddi imkanlar ile inşaa edilmiştir. Bu yapıların bir çoğunun inşaası sırasında kendi dönemlerine ait inşaat yönetmelikleri gözetilmemiş, eksik ve/veya yanlış detaylarla yapım gerçekleştirilmiştir. Gelişmiş ülkelerde savaş sonrasında inşaat sektöründe bu olumsuzluklar yaşanırken gelişmemiş ülkelerde ise savaşın getirdiği ekonomik yıkım büyük iç ve dış göçleri tetiklemiş ve bu da şehirlerde çarpık yapılaşmayı kontrol edilemez boyutlara taşımıştır. Çarpık yapılaşma doğal olarak beraberinde yapı yönetmeliklerine uymayan, son derece düşük malzeme ve işçilik kalitesine sahip devasa bir yapı stoğunu oluşturmuştur. Sismik olarak aktif olmayan bölgeler...
Reinforcement corrosion is the risk most frequently cited to justify concrete durability research... more Reinforcement corrosion is the risk most frequently cited to justify concrete durability research, especially where it is induced by chlorides. Surface-applied corrosion inhibitors are widely used to mitigate the corrosion process both for carbonation and chlorides of steel reinforcement in concrete. They are applied onto the surface of hardened concrete and penetrate towards steel reinforcement. This paper discusses the corrosion inhibition performance of a new generation of a dual-phase surface-applied corrosion inhibitor (DP-SACI), and its efficiency in corrosion induced by chlorides over 3% referred to cement mass, and also in pre- and post-cracked structures. This corrosion mitigation activity was evaluated onsite for almost four years, in a sea wall exposed to XS1 ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resist...
Reinforcement corrosion is the risk most frequently cited to justify concrete durability research... more Reinforcement corrosion is the risk most frequently cited to justify concrete durability research, especially where it is induced by chlorides. Surface-applied corrosion inhibitors are widely used to mitigate the corrosion process both for carbonation and chlorides of steel reinforcement in concrete. They are applied onto the surface of hardened concrete and penetrate towards steel reinforcement. This paper discusses the corrosion inhibition performance of a new generation of a dual-phase surface-applied corrosion inhibitor (DP-SACI), and its efficiency in corrosion induced by chlorides over 3% referred to cement mass, and also in pre- and post-cracked structures. This corrosion mitigation activity was evaluated onsite for almost four years, in a sea wall exposed to XS1 ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resistance measurements). All of these electrochemical parameters provide accurate information for on-site structures about the efficiency over the time of surface-applied corrosion inhibitors. The effectiveness of the dual-phase surface-applied corrosion inhibitor proved to be up to 99%, even with ongoing corrosion and 0.3 mm cracks near the rebar. The use of DP-SACI provides a non-destructive repair method that inhibits the corrosion process and increases the service life of the element.
1st Croatian Conference on Earthquake Engineering, 2021
The aging building stock is turning to be an urging problem for Europe, and it costs even human l... more The aging building stock is turning to be an urging problem for Europe, and it costs even human lives in some cases. Significant part of this building stock along with infrastructure were constructed with substandard characteristics such as poor-quality material, insufficient flexural strength, wrong reinforcement details and improper design of structural system. On the other hand, Europe has highly seismically active zones where devastations are inevitable after even moderate earthquakes. In the light of these facts, countless structures are in need of retrofitting, particularly in seismic areas, while high costs, disturbance to occupants, historical heritage and environmental restrictions are major obstacles for retrofit interventions. Many substandard reinforced concrete (RC) and masonry structures should be seismically retrofitted to reduce their vulnerabilities against earthquakes. Financial constraints, disturbance to the occupants and disruption of functions of the structures are the main obstacles for proper seismic retrofitting of these substandard existing structures. Traditional retrofitting methods such as concrete and steel jacketing, are not applicable in many cases due to high disturbance to occupants and long duration of retrofitting, which may be very critical for commercial, industrial and public buildings. Besides, these methods are also not preferred for historic structures due to the incompatibility of the concrete with traditional lime-based mortars (e.g. Roman cement) and the heavy visible impact to the architectural design. In the last two decades, use of fiber reinforced polymers (FRP) in construction industry has become quite common. Academic researches go back even a decade earlier. FRPs offer practical and innovative solutions for seismic retrofitting due to their lightweight, high tensile strength and noncorrosive character. Besides, the disturbance to the architectural design of the structures are quite limited when they are retrofitted with FRPs. This opens new possibilities for masonry buildings and historic structures belonging cultural heritage.
In this experimental study, deformed bars were chemically anchored in low strength concrete and p... more In this experimental study, deformed bars were chemically anchored in low strength concrete and pull-out tests were carried out using a specially designed test setup, which allowed cone type concrete failure. The effects of several parameters, such as the depth of drilling holes, types of adhesives and surface condition of concrete in the hole, on pull-out behavior were investigated. For anchoring deformed bars in concrete, four different types of adhesives were used. The depth of the drilling holes varied between six to twelve times the bar diameter. The other test parameters were the humidity and dust condition of the concrete surface in the drilling hole. The experimental results are presented using bond strengths, bond stress-slip relationships and failure patterns.
In Turkey many existing reinforced concrete structures do not have sufficient seismic safety and ... more In Turkey many existing reinforced concrete structures do not have sufficient seismic safety and should be retrofitted. Adhesive anchors are widely used in seismic retrofit applications. To safely design such anchors, it is very important to understand their behavior under pullout forces. In this study, some of the variables, which could affect the anchor behavior such as adhesive type, anchor depth, diameter of the anchor bar and the compression strength of the base member are investigated under pullout forces. A total of 24 specimens were tested to determine their pullout characteristics, load-displacement behaviors, mode of failures and anchorage strengths. The anchor bars of 16 and 20 mm diameters were set in low strength concrete blocks (12 MPa, 16 MPa), for representing the concrete strengths of existing buildings in Turkey. Two different types of adhesives were used. The test setup was designed to allow concrete cone failure. The test results showed that the pullout capacitie...
Many existing reinforced concrete structures were constructed with substandard
characteristics. L... more Many existing reinforced concrete structures were constructed with substandard characteristics. Low quality concrete, poor transverse reinforcement details and insufficient flexural strength are among the most common deficiencies. While substandard structures are in need of retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants are major obstacles for retrofit interventions. Fiber reinforced polymers can provide feasible retrofit solutions with minimum disturbance to occupants. In this study, the basic aim is to investigate the flexural seismic performance of substandard reinforced concrete columns retrofitted with embedded longitudinal fiber reinforced polymer reinforcement without increasing the original dimensions of the columns. In the experimental study, the reference and retrofitted columns were tested under constant vertical and reversed cyclic lateral loads. Three different connection methods of aramid fiber reinforced polymer reinforcement to the footing were investigated experimentally. A significant enhancement was obtained in lateral flexural strength through the proposed retrofitting method. Furthermore, it was observed that the cyclic lateral drift capacities of the retrofitted columns were as high as 3%, which can be deemed as quite satisfactory against seismic actions. The comparison of the experimental data with analytical calculations revealed that a conventional design approach assuming composite action between concrete and fiber reinforced polymer reinforcement can be used for flexural retrofit design. Experimental results also demonstrated that strain limit for longitudinal fiber reinforced polymer (FRP) reinforcement should be remarkably lower in case of reversed cyclic loading conditions.
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Papers by Engin Seyhan
ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resistance measurements). All of these electrochemical parameters provide accurate information for on-site structures about the efficiency over the time of surface-applied corrosion inhibitors. The effectiveness of the dual-phase surface-applied corrosion inhibitor proved to be up to
99%, even with ongoing corrosion and 0.3 mm cracks near the rebar. The use of DP-SACI provides a non-destructive repair method that inhibits the corrosion process and increases the service life of the element.
characteristics. Low quality concrete, poor transverse reinforcement details and insufficient flexural
strength are among the most common deficiencies. While substandard structures are in need of
retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants
are major obstacles for retrofit interventions. Fiber reinforced polymers can provide feasible retrofit
solutions with minimum disturbance to occupants. In this study, the basic aim is to investigate the
flexural seismic performance of substandard reinforced concrete columns retrofitted with embedded
longitudinal fiber reinforced polymer reinforcement without increasing the original dimensions
of the columns. In the experimental study, the reference and retrofitted columns were tested
under constant vertical and reversed cyclic lateral loads. Three different connection methods of
aramid fiber reinforced polymer reinforcement to the footing were investigated experimentally. A
significant enhancement was obtained in lateral flexural strength through the proposed retrofitting
method. Furthermore, it was observed that the cyclic lateral drift capacities of the retrofitted
columns were as high as 3%, which can be deemed as quite satisfactory against seismic actions. The
comparison of the experimental data with analytical calculations revealed that a conventional design
approach assuming composite action between concrete and fiber reinforced polymer reinforcement
can be used for flexural retrofit design. Experimental results also demonstrated that strain limit for
longitudinal fiber reinforced polymer (FRP) reinforcement should be remarkably lower in case of
reversed cyclic loading conditions.
ambiance. The electrochemical techniques used were based on the determination of the electrical resistivity of concrete, the half-cell corrosion potential and the steel corrosion rate (from linear polarization resistance measurements). All of these electrochemical parameters provide accurate information for on-site structures about the efficiency over the time of surface-applied corrosion inhibitors. The effectiveness of the dual-phase surface-applied corrosion inhibitor proved to be up to
99%, even with ongoing corrosion and 0.3 mm cracks near the rebar. The use of DP-SACI provides a non-destructive repair method that inhibits the corrosion process and increases the service life of the element.
characteristics. Low quality concrete, poor transverse reinforcement details and insufficient flexural
strength are among the most common deficiencies. While substandard structures are in need of
retrofitting, particularly in seismic areas, problems such as high costs and disturbance to occupants
are major obstacles for retrofit interventions. Fiber reinforced polymers can provide feasible retrofit
solutions with minimum disturbance to occupants. In this study, the basic aim is to investigate the
flexural seismic performance of substandard reinforced concrete columns retrofitted with embedded
longitudinal fiber reinforced polymer reinforcement without increasing the original dimensions
of the columns. In the experimental study, the reference and retrofitted columns were tested
under constant vertical and reversed cyclic lateral loads. Three different connection methods of
aramid fiber reinforced polymer reinforcement to the footing were investigated experimentally. A
significant enhancement was obtained in lateral flexural strength through the proposed retrofitting
method. Furthermore, it was observed that the cyclic lateral drift capacities of the retrofitted
columns were as high as 3%, which can be deemed as quite satisfactory against seismic actions. The
comparison of the experimental data with analytical calculations revealed that a conventional design
approach assuming composite action between concrete and fiber reinforced polymer reinforcement
can be used for flexural retrofit design. Experimental results also demonstrated that strain limit for
longitudinal fiber reinforced polymer (FRP) reinforcement should be remarkably lower in case of
reversed cyclic loading conditions.