Çimento esaslı tekstil takviyeli kompozit plakalarla ankrajlı olarak güçlendirilmiş bölme duvarlarının kayma davranışının deneysel olarak incelenmesi
Experimental analysis of the shear behavior of dividing walls that strengthened with cement-based textile reinforced composite plates and anchors
Yazar: EMRE BALCI
Danışman: PROF. DR. MUSTAFA GENÇOĞLU
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Yapı Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
İnsanların hayatlarını ve yaşam şartlarını en derinden etkileyen doğal afetlerin başında depremler gelmektedir. 21. Yüzyılda, dünyada ve ülkemizde meydana gelen depremler sonucunda binlerce insan hayatını, milyonlarcası da evlerini kaybetmiştir. Türkiye'nin jeolojik açıdan genç oluşumlu olması, aktif fay hatlarının etkin olduğu bölgede bulunması, bizleri ülkemizin bir deprem ülkesi olması gerçeğiyle karşı karşıya bırakmaktadır. Bu tez çalışmasının yürütüldüğü aşamada, 6 Şubat 2023'te dokuz saat arayla meydana gelen, merkez üsleri sırasıyla Kahramanmaraş'ın Pazarcık ve Ekinözü ilçeleri olan, 7.7 ve 7.6 büyüklüğünde iki büyük deprem meydana gelmiştir. Depremler, başta Türkiye'de on ili içine alan geniş bir alan olmak üzere Suriye' de de yıkıcı etkilere sebep olmuştur. Türkiye'de 50 bin 96 can kaybına ve 107 bin 204 kişinin yaralanmasına sebep olan depremler tüm ülkeyi yasa boğmuştur. Meydana gelen depremler sonucunda ortaya çıkan tablo, 1939 Erzincan Depremi ve 1999 Marmara Depremiyle aynı şeyi söylemektedir. "İnsanların doğayla olan savaşlarını kazanma ihtimali yoktur." Bu sebeple hayatın her alanında yaşanabilecek tüm doğal afetlere karşı önlem almak, onların yıkıcı etkilerini kabul etmek ve en aza indirmek hayati önem taşımaktadır. Bu bağlamda yeni inşaa edilecek binalarda yönetmeliklere uyulmalı ve gerekli mühendislik hizmetleri alınmalı, mevcut yapı stoğunun olası depremlerde alabileceği hasar durumu incelenmeli ve olası deprem senaryolarına göre riskli bölgelerde bulunan yapıların depreme karşı dayanımları gerekli testler ve analizler sonucunda belirlenmelidir. Yapılan çalışmalar sonucunda olası deprem etkilerini karşılayamayacak yapılarda güçlendirme veya yıkıp yeniden inşaa etme yöntemleri tercih edilebilir. Güçlendirme teknikleriyle gerekli dayanımın kazandırılabileceği, güçlendirme işleminin uygulanmasında çeşitli zorluklar bulunmayan yapılarda ve güçlendirme maliyetinin yeniden yapılma maliyetinin ~ %40'ını geçmediği durumlarda mevcut yapılar çeşitli yöntemlerle güçlendirilebilir. Bu güçlendirme çalışmalarından biri de betonarme kolon ve kirişlerden oluşan çerçeveler içerisinde bulunan bölme duvarların güçlendirilmesidir. 2007 deprem yönetmeliğimizden itibaren betonarme çerçeveler içerisinde bulunan duvarların binaların yük taşıma kapasitesine sağladıkları etkinin  göz önüne alınması gerektiği ifade edilmiştir. Nitekim, 2018 yılında yayımlanan Türkiye Bina Deprem Yönetmeliğinde bu duvarların taşıyıcı sisteme etkileri dikkate alınmıştır. Bu bağlamda 2018 Deprem yönetmeliğinde çeşitli güçlendirme tekniklerine de yer verilmiştir [1].  Mevcut yapılarda uygulanacak güçlendirme işlemlerinin önemini anlamak adına 2009 yılında O.D.T.Ü' de yürütülen bir yüksek lisans tezi çarpıcı bir örnektir. "Orta-Katlı Bir Betonarme Binanın Lifli Karbon Polimerleri Kullanarak Güçlendirilmesi" isimli tez çalışması kapsamında Antakya Belediye Kooperatif Evleri A1-A2-A3 Bloklarından A1 Bloğunda FRP ile kolon güçlendirme, A2 Bloğunda binaya dıştan perde duvar eklenmesi ve bölme duvarlarının FRP ile güçlendirilmesi yöntemleri uygulanırken A3 Bloğunda herhangi bir güçlendirme işlemi uygulanmamıştır [2]. 6 Şubat 2023' te meydana gelen 7.7 ve 7.6 büyüklüğündeki Kahramanmaraş depremleri ve 6.4'lük Hatay depreminin ardından A1 ve A2 Bloklarında kontrollü hasar meydana gelirken A3 Blok tamamen yerle bir olmuştur. 
Bu tez çalışması kapsamında mevcut yapı stoğunun olası deprem etkilerini karşılayamayacak kısmı için yatay deprem kuvvetlerine karşı çimeto esaslı tekstil takviyeli kompozitler (TRCC) kullanarak yeni bir güçlendirme metodu geliştirmek hedeflenmiştir. Üretilecek kompozitlerde AR Glass tekstil malzemesi kullanılmıştır. 
Bu amaçla, İ.T.Ü Yapı ve Deprem Mühendiskiği Laboratuvarında TRCC kompozit plakalar üretilmiştir. Daha sonra bölme duvarlara ilişkin deneylerde denenmek üzere 760 mm x 760 mm boyutlarında 5 adet duvar numunesi üretilmiştir. Duvar numunelerinin biri sadece sıvanmış ve şahit numune olarak bırakılmıştır. Bir adedinde 2 kat AR Glass kullanılarak üretilmiş TRCC, diğerinde 4 kat AR Glass malzeme kullanılarak üretilmiş TRCC, bir diğerinde 6 kat AR Glass malzeme kullanılarak üretilmiş TRCC ve son olarak 8 kat AR Glass malzeme kullanılarak üretilmiş TRCC ile güçlendirme işlemi gerçekleştirilmiştir. Güçlendirme işleminin uygulanabilirliğini araştırmak amacıyla bölme duvarlarının her iki yüzü de 10 mm kalınlığında sıva ile kaplanmıştır. Duvar güçlendirme işlemlerinde TRCC plakalar 15 cm x 15 cm boyutlarında kesilmiş ve kenarlarından 2 cm mesafeden pahlanmıştır. Duvar numunelerine yüksek dayanımlı özel harç ile yapıştırılan TRCC plakalar aynı zamanda pah boşluklarından deprem yönetmeliğimizin de önerdiğine benzer bir ankraj sistemiyle TRCC malzeme kullanılan ankrajlarla duvar numunesine sabitlenmiştir. Üretilen numuneler Yapı ve Deprem Laboratuvarında denenmiş, taşıdıkları maksimum yükler, hasar düzeyleri, rijitlikleri, enerji yutma seviyeleri birbiriyle kıyaslanmıştır.

Abstract:
Earthquakes are one of the most ruthless natural disasters that affect people's lives and living conditions. In the 21st century, thousands of people lost their lives and millions lost their homes as a result of earthquakes that took place in the world and in our country. The fact that Turkey is geologically young and is located in the region where active fault lines are effective confronts us the fact that our country is an earthquake country. During the course of this thesis, two large earthquakes with a magnitude of 7.7 and 7.6 occurred on February 6, 2023, nine hours apart, with epicenters in Pazarcık and Ekinözü districts of Kahramanmaraş, respectively. These earthquakes had devastating effects in a wide area including ten provinces in Turkey and also in Syria. Earthquakes in Turkey, which caused fifty thousand ninety-six deaths and one hundred seven thousand two hundred four injuries, left the whole country in mourning. The picture that emerged as a result of the earthquakes that took place says the same thing with the 1939 Erzincan Earthquake and the 1999 Marmara Earthquake. "It is never possible for humans to win the war with nature." For this reason, it is vital to take precautions against all natural disasters that can be experienced in all areas of life, to accept their destructive effects and to try to minimize their devastating effects. In this context, earthquake regulations must be complied with and necessary engineering services must be obtained in newly constructed buildings. The damage status of the existing building stock in possible earthquakes should be examined and the earthquake resistance of the buildings located in risky areas should be determined as a result of the necessary tests and analyzes according to the possible earthquake forecasts. As a result of the studies, strengthening or demolition and rebuilding methods can be preferred in structures that are expected to suffer major damage in the event of possible earthquakes. Existing structures can be reinforced with various methods where the necessary strength can be gained by reinforcing techniques, where there are no difficulties in the application of the reinforcing process, and where the cost of strengthening does not exceed ~ 40% of the cost of reconstruction. One of these reinforcing processes is the reinforcement of infill walls in frames made of reinforced concrete columns and beams. It has been stated that it would be appropriate to consider the contribution of the infill walls between the reinforced concrete frames to the bearing capacity of the reinforced concrete buildings as of the 2007 Turkish Earthquake Code. In the Turkish Earthquake Code published in 2018, the effects of the infill walls between the frames on the load-bearing system were taken into account. In this context, various strengthening techniques are also included in the 2018 Earthquake Code [1]. A master's thesis conducted at O.D.T.Ü in 2009 is a striking example in order to understand the importance of strengthening processes to be applied in existing structures. Within the scope of the thesis study titled "Seismic Strengthening of a Mid-Rise Reinforced Concrete Frame Using CFRPs: An Application From Real Life", the methods of column reinforcement with FRP in Block A1 from Antakya Belediye Kooperatif Evleri A1-A2-A3 Blocks, adding shear walls from outside to the building and strengthening the partition walls with FRP were applied in Block A2. On the other hand, no strengthening process was applied in the A3 Block [2]. After the 7.7 and 7.6 magnitude Kahramanmaraş earthquakes and the 6.4 earthquake in Hatay, which occurred on February 6, 2023, controlled damage occurred in Blocks A1 and A2, while Block A3 was completely destroyed.
Within the scope of this thesis, it is aimed to develop a new strengthening procedure by using cement-based textile reinforced composites (TRCC) against lateral earthquake forces for the part of the existing building stock that cannot withstand possible earthquake effects.
Textile Reinforced Cementitious Composite (TRCC), which are the subject of the study, are produced by combining a cement mortar with high compressive strength and textile reinforcement with high tensile strength through various processes. These composites are reinforced concrete products with high load-bearing capabilities, light weight, easy to apply and thin structure.
In order for the textile material to bond with cement-based components, it is sufficient to cover its surfaces with a thin layer of cement. In addition, by using textile materials, the risk of corrosion seen in steel reinforced concrete is prevented. The textile components used provide advantages in the tensile and bending strength of cement-based composites. Apart from their mechanical contributions, textile-containing materials increase the ductility of composites and offer design freedom.
In the production of textile-reinforced cement-based composites, high-strength cement mortar is used as the main component, and textile materials are used as reinforcement elements to absorb tensile loads. Textiles are produced as a weaving system by passing a large number of fibers, called warp and weft, in two directions, horizontally and longitudinally, in a grid system or under and over each other. While the reinforced concrete element can be strengthened in one direction in strengthening processes with FRP, strengthening can be achieved in two directions thanks to the fibers arranged in two directions in the structure of textiles in the strengthening process with TRCCs.
Textile materials used in textile reinforced composites vary according to the fibers (PVA, PP, PE, AR Glass, carbon, basalt, aramid, etc.) and the arrangement of these fibers. For this reason, the type of textile to be chosen in the reinforcement process provides a wide freedom of choice depending on the place and purpose of use. It is important to use a matrix mortar that is compatible with the selected textile material. For example, woven plane textile materials are materials with a dense weft and warp structure. Therefore, the matrix mortar to be used in woven type textiles must have a fluid structure and must penetrate between all fibers and cover the entire surface of the textile material.
AR Glass textile material, consisting of network-shaped fibers, was used in the TRCCs produced within the scope of the thesis study, as in other textile products. The relevant textile material is produced by passing the fibers arranged perpendicularly and parallelly over and under each other and bonding at the intersecting points, gluing or leno weaving techniques. Another important reason for choosing AR Glass textile material in the study is that the cement mortar used as matrix can easily pass through the fibers that make up AR Glass. In this way, it can be ensured that the textile material and matrix mortar used in TRCC work more harmoniously and show a homogeneous structure.
Within the scope of the thesis, the technique called PPR (Pull-Pour and Roll) was used in the production of textile reinforced cement-based composites (TRCC). First of all, the AR Glass textile material to be used in production was wrapped on one of the circular drums located at one end of the machine, which was designed to apply the PPR method. AR Glass was then passed through two more drums to ensure that the textile material remained taut during production, and was laid on the production line on the machine in a taut state. High strength cement mortar is filled into the mortar chamber on the machine. Then a command was given to activate the machine. The mortar chamber was opened and some matrix mortar was slowly deposited onto the textile material. The cement mortar was spread on the textile material with the help of a spatula. As the belt progresses, the textile mortar is passed through a scraper device to ensure that the mortar is equal and of the desired thickness everywhere on the textile material. 
The one-piece plate-shaped inner mold of 500 mm x 1000 mm, located at the other end of the machine, is covered with bubble nylon material for easy separation of the composite to be produced from the mold. The plate was then covered with cement-based mortar to form a thin layer. The mortar-soaked textile material was attached to one end of the machine via the moving production line and brought to the single-piece inner mold in the form of a plate rotating at a certain speed, covered with cement-based mortar. Here, the textile material separated from the production line was wrapped tautly on the plate mold by applying pressure in 2 layers, 4 layers, 6 layers and 8 layers. Afterwards, the AR Glass textile material was cut and separated from the mold. The fresh composite material wrapped in the mold is wrapped with a nylon cover, leaving no air gap. In this way, it is aimed to have a smooth surface of the composite material to be placed between the two-piece outer mold and to separate it from the mold easily. The composite material wrapped in nylon was separated from the machine with the help of a crane and placed in one of the outer molds consisting of two parts. Then, after the second part of the outer mold was placed on the composite material, the outer mold consisting of two parts was connected to each other with the help of screws. The samples, which were kept in the mold for a day, were cut with the help of a stone cutting machine, removed from the mold, and then kept in the curing pool for 28 days to gain strength. After the composite samples taken out of the pool were dried in the laboratory environment, they were cut into 150 mm x 150 mm dimensions and beveled 20 mm from the edges to cover the partition walls produced. The purpose of the chamfering process is to ensure that the AR Glass material, which is passed through the walls to be drilled through the anchor gaps between the chamfers of the samples to be glued to the walls, is pasted on the samples in the form of a bundle and to ensure that the samples work together under vertical loads after the wall is plastered at the final stage. Then, 5 holes with a diameter of 5 mm were drilled on the samples with the help of a drill. The purpose of the holes is to check that the mortar to be used when coating the samples on the wall reaches the entire surface of the sample and ensures the best adherence of the wall and composite samples. While the samples were coated on the walls with a mortar with the same content as the matrix mortar, care was taken to ensure that the mortar came out of the holes opened on the composite samples. In this way, it will be understood that the sample is completely covered with mortar from its four corners and the middle.
Five wall samples with dimensions of 760 mm x 760 mm were produced to be tested in experiments on partition walls. One of the wall samples was only plastered and left as a witness sample. The strengthening process was carried out in one of them with TRCC produced using 2 layers of AR Glass, in another with TRCC produced using 4 layers of AR Glass material, in another with TRCC produced using 6 layers of AR Glass material and finally with TRCC produced using 8 layers of AR Glass material. In order to investigate the feasibility of the strengthening process, both sides of the partition walls were covered with 10 mm thick plaster. In wall strengthening operations, TRCC plates were cut in 15 cm x 15 cm dimensions and chamfered at a distance of 2 cm from their edges. TRCC plates, which were adhered to the wall samples with high-strength special mortar, were also fixed to the wall sample through the chamfer gaps with an anchor system similar to what our earthquake regulations recommend, using anchors using TRCC materials. In the experiments, wall samples were placed on the loading device at an angle of 45o and their diagonals were aligned with the vertical and horizontal axes, and were tested at continuously increasing loads under vertical pressure forces. Changes occurring in the non-linear region in the shear strength and shear stiffness of the wall samples tested up to the collapse load under vertical pressure forces were recorded. Wall samples were placed in the experimental setup using 2 steel caps. The main purpose of placing the caps on the vertical diagonal of the sample and filling the gaps between the steel caps and the wall sample with cement mortar is to ensure that the sample and caps work together and to distribute the pressure load to the sample homogeneously. In order to prevent movement of the wall sample and headers during the experiments, the sample was fixed to the loading mechanism with the help of rods and bolts. In the experiments, a hydraulic jack capable of giving a load of 1000 kN was used for loading, and the applied pressure loads were recorded with the help of a load meter capable of measuring up to 1000 kN. The produced samples were tested in the Structure and Earthquake Laboratory, and their maximum loads, damage levels, stiffness and energy absorption levels were compared with each other.