Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 3Citation - Scopus: 3Seismic Testing and Modeling of Full-Scale Substandard Rc Columns Retrofitted With Sprayed Gfrm With and Without Basalt Mesh Under High Axial Compression and Shear Demand(Asce-Amer Soc Civil Engineers, 2025) Kian, Nima; Demir, Ugur; Ates, Ali Osman; Celik, Oguz C.; Ilki, AlperThis study presents the experimental and analytical hysteretic behaviors of eight full-scale RC square and rectangular columns. The columns were designed to have different shear spans that represent: (1) a column that complies with the Turkish Government Ministry of Reconstruction and Resettlement's ( 1975) seismic design code, Turkish Seismic Design Code (TSDC); (2) a substandard column; and (3) two sprayed glass fiber-reinforced mortar (GFRM)-retrofitted counterparts of the substandard column with and without basalt mesh. The substandard columns were designed to be subjected to relatively high shear ratios (i.e., the ratio of the shear force that corresponds to the moment capacity to shear strength of the cross section) up to 0.85 and with a high axial load-to-capacity ratio of 0.75. All columns were tested under constant axial load and reversed cyclic lateral displacement excursions. The results revealed that the columns that complied with the TSDC showed satisfactory behavior for seismic performance, and the performance of the substandard columns was extremely poor. However, the hysteretic performance of the substandard columns that were subjected to high axial stress and shear significantly improved after the proposed retrofitting. Finally, a numerical model was developed in OpenSees to reproduce the hysteresis curves of the specimens. The slip of the longitudinal bars at the column-foundation interface, strain penetration into the foundation, and buckling of the longitudinal bars in compression were accounted for in the modeling. The results are in good agreement with the experimental hysteresis curves. The performance levels of the columns are further specified, and the predictions of the current seismic codes were analyzed: (1) the European Committee for Standardization's 2005 code, Eurocode 8: Design of structures for earthquake resistance; Parts 1-3: Strengthening and repair of buildings (EC8-3); and (2) the Turkish Government Ministry of Interior Disaster and Emergency Management Authority's 2018 code, Turkish Building Earthquake Code (TBEC). The TBEC provided more accurate estimates of plastic rotation capacities for substandard specimens. In contrast, EC8-3 overestimated the plastic rotation capacity when shear stresses were relatively high due to lower shear span-to-depth ratios (a/d).Conference Object Citation - Scopus: 3Seismic Performance of Cfrp Jacketed Sub-Standard Rc Columns Under High Axial Stress and Shear Demand(Springer, 2022) Demir, Merve Nur; Demir, Uğur; Demir, Cem; İlki, AlperIn the last decades, lessons learnt from the major earthquakes, that occurred in many countries, brought revisions in prevailing seismic design codes. As a consequence of this phenomenon, the current building stock in Turkey is mainly comprised of reinforced concrete (RC) buildings which were designed according to different seismic design codes. The presented paper is a component of a comprehensive investigation which containing three variables i) high axial load ratio defined as axial load divided by the axial capacity, ii) high shear demand defined as the ratio of shear demand at flexural yielding to shear resistance and iii) low transverse reinforcement ratio owing to large spacing among steel reinforcements. Thus, a total of four full-scale square RC columns comprised of i) one column designed to comply with the former Turkish Seismic Design Code (TSDC, 1975) and ii) three columns which are not compliant to any design codes (referred as sub-standard), were tested under high axial load ratio, 0.4 for code-conforming and 0.75 for sub-standard columns, combined with reversed cyclic lateral loading. The columns were also designed to have high shear demand in the order of 0.62 and 0.80 for bare sub-standard according to ACI 318 (2019) and TBEC (2018) design codes as sometimes observed in existing sub-standard structures. In addition to that, the ratio of shear demand for the code-conforming column is calculated 0.43 and 0.50 as per design codes, respectively. Besides, the ratio of transverse reinforcement area to the minimum required transverse reinforcement area was 0.19 and 0.77 for sub-standard columns according to ACI 318 (2019) and TBEC (2018), respectively. For the code-conforming column, the aforementioned ratio was 0.57 and 1.32 for both design codes, in the same manner. One of the sub-standard columns was kept as a reference column while the other two of them have been externally jacketed with one layer or two layers of carbon fiber-reinforced polymer (CFRP) sheets. Test results pointed out that the confinement provided by CFRP jacketing has remarkably improved the performance of seismically-deficient RC columns subjected to high axial compression under high shear demand in terms of lateral load capacity and ductility. The experimental results were also supplemented with theoretical work to evaluate the effects of CFRP jacketing on the seismic behavior of sub-standard RC columns.Article Citation - WoS: 14Citation - Scopus: 14Thermal Simulation of Retrofits To Existing Mass Housing in Turkey for Energy Efficiency(Sila Science, 2011) Yıldız, Yusuf; Durmuş Arsan, ZeynepEnergy consumption in the existing residential building stock in Turkey is currently excessive. Mass housing, comprising a major portion of the officially-registered residential stock, carries enormous potential for energy savings even in the short run. This paper describes a case study in a mass housing area in Izmir, Turkey, in order to demonstrate the possibility of significant energy savings by implementing case-specific energy-efficient retrofitting scenarios and relating them with the payback periods. Building energy analysis software was used to examine thirteen scenarios consisting of various combinations of four main retrofitting options: addition of extra insulation for building envelope, replacement of existing glazing, regulation of air infiltration rate and indoor set point temperature. These scenarios revealed that annual energy savings of up to 62% are achievable and that the customer payback period for the best retrofitting scenario is 34 years.Article Citation - WoS: 7Citation - Scopus: 9Simulation-Based Retrofitting of an Educational Building in Terms of Optimum Shading Device and Energy Efficient Artificial Lighting Criteria(Znack Publishing House, 2016) Bayram, Göze; Kazanasmaz, Zehra TuğçeThe high level of daylight performance is crucial to increase academic and work performance of students and staff in educational buildings which are mostly used during the daytime. New design solutions have potential to reach optimum lighting conditions and minimum energy consumption. So, the purpose of this study is to evaluate and propose an energy efficient lighting design for an educational building. The aim is to find the optimum type of shading device with appropriate slat angles, transmittance of glazing, and the luminaire type/layout as well. Utilizing DIALux simulations, scenarios for combinations of these inputs are tested for classrooms, offices and a laboratory, which are non-identical due to their orientation, size, window characterization and facade organization. The procedure covers all significant days (winter/ summer solstice and equinoxes) during one year. Such an integrated approach would be proposed for lighting design and retrofit applications. © 2016, LLC Editorial of Journal “Light Technik”. All rights reserved.Article Citation - WoS: 74Citation - Scopus: 85A Transdisciplinary Approach on the Energy Efficient Retrofitting of a Historic Building in the Aegean Region of Turkey(Elsevier Ltd., 2015) Şahin, Cem Doğan; Durmuş Arsan, Zeynep; Tunçoku, Selim Sarp; Broström, Tor; Gökçen Akkurt, GüldenAbstract Buildings account for 40% of total energy consumption in the European Union, yet at the same time they have considerable energy saving potentials. Historic buildings should be treated different from contemporary ones when it comes to energy improvements. The specifications which underline historical, sociocultural and architectural values require certain care during realization of energy saving implementations to sustain these values. The purpose of this study is to demonstrate how the energy efficient retrofitting in historic buildings should be managed in a transdisciplinary approach with a case study conducted on the historic building in ̄zmir - Turkey. A detailed building energy simulation tool was used to determine the impacts of energy efficient retrofits. The actual energy consumption of case building was based on the utility bills regarding electricity and heating fuel consumption. Building energy simulation tool was calibrated by comparing the measured and simulated indoor air temperatures and total energy consumptions. The inappropriate retrofits, which contradict to the cultural heritage values, were eliminated with a transdisciplinary approach. Later appropriate retrofits were gathered into three packages to evaluate their effects on the energy consumption. The results show that energy saving of more than 34% can be obtained without damaging the heritage values.