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Öğe Analytical and experimental studies on infilled RC frames(Academic Journals, 2010) Baran, Mehmet; Sevil, TuğçeAlthough hollow brick infills, widely used as partition walls, are considered as non-structural members, experimental studies revealed that hollow brick infills have favourable effects on strength and stiffness of structures. In this work, analytical studies were conducted to investigate the hollow brick infill behaviour, in which infills were modeled by diagonal compression struts. Results were compared with experimental ones obtained from tests of one-bay, one or two story reinforced concrete (RC) frames, tested under both vertical and reversed-cyclic lateral loads simulating earthquake. Test frames have intentionally been constructed poorly to reflect the most common deficiencies encountered in Turkey such as strong beam-weak column connections, insufficient confinement, low-grade concrete, poor workmanship and insufficient lap-splice length. Experimental studies shows that hollow brick infills increased both strength and stiffness of RC frames. Analytical studies conducted, shows that hollow brick infills could adequately be modeled by diagonal compression struts.Öğe Beton panellerle güçlendirme - kuramsal yaklaşım(2010) Baran, Mehmet; Canbay, Erdem; Tankut, TuğrulYapılarda bulunan boşluklu tuğla duvarların yüksek dayanımlı önüretimli beton paneller kullanılarak güçlendirilmesi ilkesine dayanan ekonomik, yapısal olarak etkili ve uygulaması kolay bir depreme karşı güçlendirme yöntemi geliştirilmiştir. Bu teknik, yapının boşaltılmasını gerektirmemekte ve konut kullanıcılarına fazla rahatsızlık vermeden uygulanabilmektedir. Bu amaçla, toplam onsekiz adet boşluklu tuğla dolgu duvarlı çerçeve, deprem yükünü benzeştirecek tersinir tekrarlanır yatay yükler altında test edilmiştir. Deney elemanları altı değişik önüretimli beton panel kullanılarak güçlendirilmiştir. Bu çalışmada, yüksek dayanımlı önüretimli beton paneller kullanılarak güçlendirilen boşluklu tuğla dolgu duvarları hem eşdeğer çapraz çubuk elemanları ile hem de eşdeğer kalınlığa sahip duvarlar ile modellenmiştir. Deney sonuçları, sözü edilen iki yaklaşımın kuramsal sonuçları ile karşılaştırılmıştır.Öğe Betonarme Çerçeveli Yapıların Önüretimli Beton Panellerle Sismik Güçlendirilmesi(Kırıkkale Üniversitesi, 2009) Baran, Mehmet; Okuyucu, Dilek; Tankut, TuğrulTürkiye’deki birçok bina heran olması olası büyük depremlere karsı yeterli dayanıma sahip degildir. Yakın zamanda meydana gelmis büyük depremler hem ülke ekonomisine büyük zarar vermisler hem de birçok insanın hayatına mal olmuslardır. Gelecekteki depremlerin bu kadar büyük zararlar vermemeleri için sismik güçlendirme yöntemleri olabildigince çok miktarda zayıf binalara uygulanmalıdırlar. Genelde uygulanan güçlendirme yöntemleri binanın da bosaltılmasını öngören yorucu ve zaman alan insaat islerine yol açmaktadır. Bu çalısmada, Türkiye’deki binaların büyük bir kısmını olusturan betonarme çerçeveli yapılara uygulanabilecek ve yapı bosaltmayı gerektirmeyen bir sismik güçlendirme yöntemi gelistirilmektedir. Bu çalısmada önerilen teknigin prensibi, yapıda bulunan bosluklu tugla dolgu duvarların yüksek dayanımlı önüretimli beton paneller kullanılarak güçlendirilmesi esasına dayanır. Bu amaçla, Türkiye’deki binaların büyük çogunlugunda rastlanan kusurlara sahip dört adet 1/3 ölçekli iki katlı tek açıklıklı çerçeve, deprem yükünü benzestirecek tersinir-tekrarlanır yatay yükler ve sabit düsey yükler altında test edilmistir. Deneylerde iki degisik panel tipi kullanılmıstır.Öğe Birden Fazla Boşluklu Çift Doğrultulu Betonarme Döşemelerin Zımbalama Performansının İyileştirilmesi için Tekstil ile Güçlendirilmiş Sıva Şeritler ile Güçlendirilmesi(Kırıkkale Üniversitesi, 2021) Mercimek, Ömer; Ghoroubi, Rahim; Anıl, Ozgur; Baran, MehmetBetonarme kirişsiz döşemelerde meydana gelebilecek olan ani ve gevrek bir şekilde, hiçbir deformasyon belirtisi göstermeden oluşan zımbalama göçme mekanizması yapı içerisinde yaşayanlara zarar verebilecek son derece tehlikeli bir göçme şeklidir. Bu nedenle tasarım aşamasında kaçınılan göçme mekanizmalarının başında gelmektedir. Betonarme döşemelerde havalandırma, elektrik veya dogalgaz gibi alt yapı sistemlerinin geçirilmesi veya merdiven ya da asansör boşluğu gibi mimari zorunluluklar nedeniyle bırakılan boşlukların, döşemelerin zımbalama dayanımını ve davranışını olumsuz etkilediği bilinmektedir. Ancak birden fazla boşluklu çift doğrultulu betonarme döşemelerin zımbalama yüklemesi etkisi altındaki davranışının incelendiği bir araştırmaya literatürde rastlanmamıştır. Bu nedenle betonarme çift doğrultulu döşemelerde birden fazla boşluğun döşemelerin zımbalama davranışı üzerindeki olumsuz etkilerinin belirlenmesi ve boşlukların meydana getirdiği davranış problemlerinin azaltılabilmesi için tekstil ile takviye edilmiş sıva şeritler ile döşemelerin güçlendirilmesinin incelendiği deneysel bir çalışma planlanmıştır. Bu çalışma kapsamında biri boşluksuz referans elemanı, 4 deney elemanı ise 300x300 mm boyutlarında kare kesitli iki adet boşluklu olacak şekilde toplamda 5 döşeme deney elemanı üretilmiştir. Boşluklu deney elemanlarının ikisi tekstil ile güçlendirilmiş sıva katmanlı (TGSK) şeritler ile güçlendirilerek deney elemanlarının zımbalama davranışı üzerinde boşlukların meydana getirdiği olumsuz etkilerin ne ölçüde iyileştirilebildiği deneysel olarak araştırılmıştır. Çalışma kapsamında TGSK şeritler ile geliştirilen ve uygulanan güçlendirme metodunun döşemelerin zımbalama dayanımını önemli ölçüde artırdığı, boşlukların meydana getirdiği olumsuz etkileri sınırlandırdığı görülmüştür.Öğe Deflections of reinforced concrete beams with transverse openings of different geometries(Techno-Press, 2021) Kalkan, Ilker; Ceylan, Ece; Kartal, Saruhan; Baran, MehmetThe present study pertains to the in-plane bending deflections of reinforced concrete beams with multiple regular transverse openings along the beam length. The total deflections in the beam were obtained from bending deflections and the additional deflections from the Vierendeel panel action. The accuracy of the deflection estimates from the proposed formula were observed to depend on the opening geometry. Among different geometries, the presence of rectangular and parallelogram web openings resulted in the experimental deflections to deviate more considerably from the analytical values due to the stress concentrations around the corners of the openings. Consequently, a multiplier was incorporated into the deflection formula to account for the opening geometry. The new revised formula was found to generate analytical load-deflection curves in close agreement with the experimental ones and service-load deflections close to the FEA values of beams with varying amount of tension reinforcement. The diagonal reinforcement around the openings and the short stirrups in the posts and chords increased the accuracy of the analytical deflection estimates by reducing the undesired additional deformations in the beam due to the poorer integrity of the posts and chords around the openings.Öğe Experimental Study on Seismic Strengthening of Reinforced Concrete Frames by Precast Concrete Panels(Amer Concrete Inst, 2011) Baran, Mehmet; Tankut, TugrulThe purpose of this study is to investigate the behavior of reinforced concrete (RC)frames under cyclic loads strengthened by using precast concrete (PC) panels. The idea is to transform the existing hollow brick infills into strong and rigid infills by bonding relatively high-strength PC panels with a thin layer of epoxy mortar By this method, the seismic behavior of the frame is improved. For this purpose-one being reference-a total of 11 one-third scale, one-hay, two-story deficient RC frames were tested under reversed cyclic lateral loads. Six different panel types were used for strengthening purposes. It was observed that the strength, lateral stiffness, and energy dissipation capacity of strengthened frames were significantly improved.Öğe An experimental study on spiral columns(Gazi Univ, Fac Engineering Architecture, 2011) Baran, Mehmet; Dincer, SarpIn this study, minimum confinement reinforcement requirement of spiral columns under combined bending and axial load was investigated. Since the object of this study was to test the equation proposed by Ersoy and Ozcebe [1] experimentally and to report the results comprehensively, twelve spiral column specimens were tested under combined bending and axial load [2, 3]. Six specimens were designed according to one of the equations used in the Turkish [4] and ACI (American Concrete Institute) codes [5] and the other six specimens were designed according to the proposed equation. The variable parameters used in this study were the volumetric ratio of spiral steel (calculated by the code and the proposed equation), the ratio of the gross concrete area to the confined core area and the yield strength of the spiral steel. Test results of the columns designed according to the current Code equations, based on the axially loaded column behavior, are compared with the test results of the columns designed according to the proposed equation, based on the eccentrically loaded column behavior.Öğe Fret Özelliklerinin Fretli Kolon Davranışına Etkileri(Kırıkkale Üniversitesi, 2011) Baran, MehmetBu çalışmada, fret özelliklerinin bileşik eğilme ve eksenel yük altındaki fretli kolonların davranışına etkileri incelenmiştir. Çalışmanın amacı Türk [1] ve Amerikan Beton Enstitüsü’nün Yönetmeliklerinde [2] önerilen iki adet denklemden birine göre hazırlanan deney elemanlarını test etmek ve sonuçları ayrıntılı açıklamak olduğundan altı adet fretli kolon elemanı bileşik eğilme ve eksenel yük altında test edilmiştir [3, 4, 5]. Deney elemanlarının değişken parametreleri toplam beton alanının çekirdek beton alanına oranı ve fretin akma dayanımıdır. Yönetmelikte verilen ve eksenel yüklenmiş kolon davranışını esas alan denklemlere göre hazırlanan kolon numunelerinin deneysel moment-eğrilikleri ve sonuçları irdelenmiş, ayrıca analitik olarak elde edilmiş eğrilikler ile de karşılaştırılmıştır.Öğe Mechanical and physical properties of cementitious composites containing fly ash or slag classified with help of particle size distribution(Fundatia Serban Solacolu, 2021) Sevim, Ozer; Baran, Mehmet; Demir, ŞükrüFly ash (FA) and granulated blast furnace slag (GBFS) produced as waste materials from coal power plants and iron/steel sector are commonly used in the concrete industry for partial substitution of cement. As the production of cement releases a substantial amount of carbon dioxide, its replacement with FA or GBFS reduces carbon dioxide emissions. This study explores the effects of FA and GBFS fineness determined by particle size distribution (PSD) on the hydration rate and compactness of cementitious materials. Firstly, FA and GBFS were classified to have three different fineness ranges with the help of PSDs without any grinding process: FA and GBFS without PSD, FA and GBFS with 0-25 µm PSD and FA and GBFS with 0-63 µm PSD. Then, flexural strength, compressive strength, and water absorption properties of cementitious composites containing FA and GBFS with four different replacement levels up to 20% wt. of cement and with three different fineness were investigated at curing ages of 7, 28, and 90 days. Results revealed that cementitious composites that contain FA and GBFS with lower PSD yield better mechanical and physical properties. © 2021, Fundatia Serban Solacolu. All rights reserved.Öğe MECHANICAL AND PHYSICAL PROPERTIES OF CEMENTITIOUS COMPOSITES CONTAINING FLY ASH OR SLAG CLASSIFIED WITH HELP OF PARTICLE SIZE DISTRIBUTION(Serban Solacolu Foundation, 2021) Sevim, Ozer; Baran, Mehmet; Demir, SukruFly ash (FA) and granulated blast furnace slag (GBFS) produced as waste materials from coal power plants and iron/steel sector are commonly used in the concrete industry for partial substitution of cement. As the production of cement releases a substantial amount of carbon dioxide, its replacement with FA or GBFS reduces carbon dioxide emissions. This study explores the effects of FA and GBFS fineness determined by particle size distribution (PSD) on the hydration rate and compactness of cementitious materials. Firstly, FA and GBFS were classified to have three different fineness ranges with the help of PSDs without any grinding process: FA and GBFS without PSD, FA and GBFS with 0-25 mu m PSD and FA and GBFS with 0-63 mu m PSD. Then, flexural strength, compressive strength, and water absorption properties of cementitious composites containing FA and GBFS with four different replacement levels up to 20% wt. of cement and with three different fineness were investigated at curing ages of 7, 28, and 90 days. Results revealed that cementitious composites that contain FA and GBFS with lower PSD yield better mechanical and physical properties.Öğe Modelling of strengthened hollow brick infills(Ice Publishing, 2013) Baran, Mehmet; özçelik, Ramazan; Sevil, Tuğçe; Canbay, ErdemStrengthening the existing hollow brick infill walls by bonding high-strength precast concrete panels or applying steel fibre reinforced mortar was found to be an occupant-friendly seismic retrofitting technique for the buildings in use with deficient reinforced concrete structural systems. Both techniques convert the existing non-structural hollow brick infill walls into load-carrying structural members. To verify the effectiveness of the techniques, 20 reinforced concrete frames with hollow brick infill walls were tested under reversed cyclic lateral loading simulating earthquake. In the present study, hollow brick infill walls strengthened by these techniques were modelled by means of two equivalent diagonal struts in the analytical studies. Analytical results matched well with the experimental results. A performance-based rehabilitation case study of an existing building showed that both techniques offer a sound and practical solution for rehabilitation studies.Öğe Occupant friendly seismic retrofit by concrete plates(Zhejiang Univ, 2013) Baran, Mehmet; Aktas, MerveAn innovative occupant friendly retrofitting technique has been developed for reinforced concrete (RC) building structures with hollow brick infill walls used as partition walls which constitute the major portion of the existing building stock in Turkey. The idea is to convert the existing hollow brick infill wall into a load carrying system acting as a cast-in-place RC wall by reinforcing it with relatively thin concrete plates bonded to the mortar coated infill wall by use of tile adhesive and fixed by I broken vertical bar 6 (6 mm diameter) bolts. Test parameters were the shape and thickness of the plates, presence of reinforcement in plates, number and arrangement of I broken vertical bar 6 bolts. It was observed that lateral strength, stiffness, energy dissipation capacity, and ductility of the strengthened infill walls were improved and behaviour was enhanced by the proposed technique. Plates with two different basic shapes were used to strengthen the test specimens.Öğe QUASI-STATIC TESTING OF ONE-BAY TWO-STOREY R/C FRAMES(Kırıkkale Üniversitesi, 2011) Baran, Mehmet; Tankut, TuğrulThe first tests on infilled frames at METU Structural Mechanics Laboratory were conducted at 1970’s. In 1986, second experimental research program was initiated in which test frames were infilled with cast-in-place reinforced concrete (RC) infills. Third experimental research program was initiated jointly with Boğaziçi University in 1994. However, the introduction of cast-in-place reinforced concrete infill walls were not suitable for strengthening of the existing building stock, since it involved messy construction works and requires evacuation. With the financial support of NATO, a new experimental research program was initiated in 2001, to develop such innovative non-evacuation retrofitting techniques, suitable for the most common type of building structures in the region. For years, one-bay two-storey specimens, called “twin frames”, were tested in the laboratory. In these tests, the specimens were tested horizontally. This set-up had been developed with the rather modest facilities available in the laboratory, and required a lengthy and tedious testing process. Since one of the aims of the study, supported by NATO Project, was to modify the test set-up for one-bay two-storey frames, a new test set-up had been developed to be used for the future studies. In the new test set-up, specimens were tested vertically. These specimens were supposedly identical to the twin frames used in the previous test series. Since experimental study is time consuming and expensive, test specimens were designed and detailed carefully, construction of the test specimens were planned considering all the details, instrumentation were designed considering the main objectives. After the two preliminary tests were conducted, modifications were done and new apparatus were added on the new set-up. In this study, both set-ups, the modifications and added apparatus are explained in details.Öğe Retrofit of Non-Ductile RC Frames with Precast Concrete (PC) Wall Panels(Multi-Science Publ Co Ltd, 2011) Baran, Mehmet; Tankut, TugrulAn economic, structurally effective and practically applicable strengthening method had been developed for reinforced concrete (RC) framed buildings. This study presents the test results on strengthening of deficient RC frames by using high strength precast concrete (PC) panels. The idea of the method is to convert the existing hollow brick infill wall into a load carrying system by bonding PC panels on to the plastered hollow brick infills. For this purpose, six (two reference and four strengthened) one-third scale, one bay, two storey deficient RC frames were tested under reversed-cyclic lateral loads. Test frames were designed and constructed with common deficiencies observed in practice. Panels having two different shapes were used as strengthening agencies. Test results showed that both strength and stiffness of the test frames were significantly improved by the introduction of PC panels. Experimental results were compared with the analytical approaches suggested by the authors.Öğe Seismic Strengthening with Precast Concrete Panels - Theoretical Approach(Turkish Chamber Civil Engineers, 2010) Baran, Mehmet; Canbay, Erdem; Tankut, TugrulAn economical, structurally effective and practically applicable seismic retrofitting technique has been developed on the basis of the principle of strengthening the existing hollow brick infill walls by using high strength precast concrete panels. The technique would not require evacuation of the building and would be applicable without causing much disturbance to the occupant. For this purpose, a total of eighteen reinforced concrete frames with hollow brick infill walls were tested under reversed cyclic lateral loading simulating earthquake. The specimens were strengthened by using six different types of precast concrete panels. In the present study, hollow brick infill walls strengthened by using high strength precast concrete panels were modeled once by means of equivalent diagonal struts and once as monolithic walls having an equivalent thickness. The experimental results were compared with the analytical results of the two approaches mentioned.Öğe SIVANMIŞ TUĞLA DOLGU DUVARLARIN ŞERİT BETON/BETONARME PANELLERLE GÜÇLENDİRİLMESİ(2014) Baran, Mehmet; Aktaş, Merve; Aykaç, SabahattinTürkiye’deki yapı stoğunun çok önemli bir bölümünün depreme karşı dayanıksız olduğu ve güçlendirilmesi gerektiği bilinmektedir. Yerinde dökülen ve yapıların çerçeve sistemlerine epoksili ankraj çubuklarıyla bağlanan betonarme (BA) dolgu duvarların yapının deprem davranışını önemli ölçüde iyileştirdiği bilinmektedir. Fakat bu yöntemin binanın boşaltılmasını ve uzun bir süre şantiyeye dönüştürmesini gerektirmesi, araştırmacıları hane sakinlerini sokağa dökmeden olabildiğince ekonomik ve aynı zamanda yapısal olarak etkili güçlendirme yöntemleri geliştirmeye yöneltmiştir. Bu çalışmada önerilen güçlendirme yönteminin prensibi yapıda var olan sıvanmış tuğla dolgu duvarların bazılarının, üzerine yapıştırılan şerit beton panellerle güçlendirilerek birer BA dolgu duvara dönüştürülmesidir. Bu amaçla, mevcut çalışma kapsamında ½ ölçeğe sahip toplam yedi adet sıvanmış tuğla duvar elemanı tersinir tekrarlanır yatay yükler altında test edilmişlerdir. Altı adet deney elemanı şerit beton/betonarme (BA) paneller yapıştırılarak güçlendirilmiştir. Deney sonuçları, beton panel yapıştırma uygulamasının deney elemanlarının yatay yük taşıma kapasitelerini artırdığını ve davranışlarını iyileştirdiğini göstermiştir.Öğe Strengthening of deficient RC frames with high strength concrete panels: an experimental study(Techno-Press, 2011) Baran, Mehmet; Susoy, Melih; Tankut, TugrulAn economic, structurally effective and practically applicable strengthening technique was developed for reinforced concrete (RC) framed buildings. The idea of the technique is to convert the existing hollow brick infill wall into a load carrying system acting as a cast-in-place RC infill wall by bonding relatively thin high strength precast concrete PC panels to the plastered hollow brick infill. For this purpose, a total of eight one-third scale, one bay, one story frames were tested under reversed-cyclic lateral loads. Test frames were designed and constructed with common deficiencies observed in practice. Four different panel types were used for strengthening. Test results showed that both strength and stiffness of the frames were significantly improved by the introduction of PC panels. Experimental results were compared with the analytical approaches suggested by the authors.Öğe Strengthening Of Plastered Hollow Brick Infill Walls Using Strip Concrete/Reinforced Concrete Panels(Gazi Univ, Fac Engineering Architecture, 2014) Baran, Mehmet; Aktas, Merve; Aykac, SabahattinIn Turkey, majority of the building stock is known to be inadequate against earthquake and is required to be strengthened. Cast-in-place reinforced concrete (RC) infill walls, connected to the frame systems by use of epoxy glued anchorages, improve the behavior of the building significantly. However, requirements of this technique such as evacuation of the building and converts it to a construction area for a long time have directed the researchers developing occupant friendly, economic and structurally effective strengthening techniques. The principle of the technique presented in this paper is based on bonding strip concrete panels on some of the plastered hollow brick infill walls available in the building such that they will behave as RC infill walls. For this purpose, seven plastered hollow brick infill wall specimens with a scale of 1/2 were tested under reversed cyclic lateral loading. Six wall specimens were strengthened with strip concrete/reinforced concrete (RC) panels. Test results showed that application of concrete panels increased lateral strength of the test specimens and improved their behavior.Öğe Strengthening of RC walls using externally bonding of steel strips(Elsevier Sci Ltd, 2013) Altın, Sinan; Kopraman, Yağmur; Baran, MehmetThe purpose of this experimental study is to investigate the hysteretic behavior of shear deficient reinforced concrete (RC) shear walls that are strengthened by bonding of steel strips. Four, 1/2 scale shear wall test specimens were constructed and tested under cyclic lateral loading. The slenderness ratio of the wall (h/l, where h = wall height, l = wall length) was 1.5. For this experimental research three wall specimens were strengthened with different steel strips configurations. The different configurations of steel strips were considered the diagonal strip, lateral strip and the combination of both lateral and vertical strips. All steel strip configurations are arranged on both sides of the shear wall symmetrically. The research focused on the effect of using bonding steel strips enhanching strength and increasing ductility of the non-seismic detailed shear walls. Test results showed that all the steel strip configurations improved the lateral strength, energy dissipation capacity and deformation capacity of the shear deficient RC wall significantly. Strengthened specimens developed the nominal flexural strength, and hence, the observed maximum base shear was controlled by flexure. Steel strips limited the opening of shear cracks and improved the lateral displacement capacity. (C) 2012 Elsevier Ltd. All rights reserved.Öğe A study on ASR mitigation by optimized particle size distribution(ELSEVIER SCI LTD, 2020) Demir, Ilhami; Sivrikaya, Burak; Sevim, Ozer; Baran, MehmetIn this study, the effect of alkali-silica reaction on binary cementitious composite systems incorporating fly ash or slag having optimized particle size distribution has been investigated. Specimens have been exposed to ASR effect according to ASTM C227 and ASTM C1260 methods. Test results, which were conducted after ASR exposure, have been discussed in terms of use of additive having optimized particle size distribution. The characterization of specimens was investigated using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopic analyzer (EDS), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis instrument (TGA). As a result of the experimental program, it was seen that the ASR effect is reduced with fly ash and slag replacement. Even, fly ash addition has been more effective than slag addition in reducing the ASR effect for the same additive ratio. In addition, addition of fly ash and slag with optimized particle-size distribution were found to be more effective in reducing the ASR effect as compared to addition of fly ash and slag without optimized particle-size distribution. (C) 2020 Elsevier Ltd. All rights reserved.
