In this study, basalt, which is common around Diyarbakır province (Turkey), is used as concrete aggregate, waste materials as mineral additives and Portland cement as binding material to prepare concrete mixes. This paper aims to determine the proper admixture levels and usability of Diyarbakır basalt in concrete mixtures based on mechanical, physical and chemical tests. Thus, in order to determine the strength and durability performance of concrete mixtures with Diyarbakır basalt as aggregate, 72 sample cubes of 150 mm were prepared in three groups: mineral-free admixture (MFA), 10% of cement amount substituted for silica fume (SFS) and 20% for fly ash (FAS) as waste material. The samples were exposed to water curing and 100g/L sulphate solution to determine the loss in weight of the concrete cubes and compressive strength was examined at the end of 7, 28 and 360 days of the specimens. Analysis of the microstructure and cracks that influence durability, were also performed to determine effects of sulphate attacks alkali-silica reactions on the specimens using scanning electron microscopy (SEM). A loss in weight of the concrete cubes and compressive strength was distinctly evident at the end of 56 and 90 days in both acids.

Türkiye is prone to earthquakes due to its location on various tectonic plates, which can lead to a loss of lives and property. Recently, on 6 February 2023, two major earthquakes hit Pazarcık and Elbistan in Türkiye, causing widespread destruction on the East Anatolian Fault (EAF) zone. Even Diyarbakır, a distant province from the epicentre, was severely affected, highlighting the need to evaluate Turkish earthquake codes. As part of this evaluation, a structural analysis was conducted on earthquake-damaged and collapsed buildings in Diyarbakır. The study analysed three buildings with different levels of damage and six collapsed buildings as case studies. The seismic parameters of the earthquakes were compared to the values in the two recent earthquake hazard maps used in Türkiye’s codes, as well as the Eurocode 8 damage limit values obtained from pushover analysis. The results revealed significant differences between the current seismic values of earthquakes and the current peak ground acceleration (PGA) values specified in the Turkish Earthquake Design Regulations. Additionally, the selected buildings showed inadequate structural behaviours, with significant differences between the expected and actual seismic performances with respect to the PGA values as one of the most important earthquake characteristics.

Mesopotamia, which is one of the strategical regions of the Middle East, has hosted numerous communities and civilizations since the ancient times of human history. This situation made the region considerably prosperous in terms of historical and cultural heritage. Ten-Eyed Bridge, that is one of the most important historical and cultural symbols of Diyarbakir, having lasted till today, became an example of this prosperous heritage. However, various interventions and deteriorations have occurred in the construction within long time due to the impact of human and nature. Because of the considerable temperature difference arising due to continental climate of the region as well as damages like the change of conditions of use, amortizations in bearing constructional components in contact with water have emerged. In this study, with the purpose of ensuring further future existence of Ten-Eyed Bridge, adopted methods for structural and physical deteriorations and protection works were examined.

Yapıların inşa edileceği zeminler eğimli olabilmektedir. Çoğu zaman tabii zemin eğimi ortadan kaldırılarak farklı kot seviyelerine oturan temeller engellenmektedir. Ancak bazı durumlarda yapı zemin eğimine göre inşa edilebilmektedir. Bu gibi durumlarda yapının zemin katında bulunan düşey taşıyıcı elemanlar farklı yüksekliklerde inşa edilebilmektedir. Bu çalışma kapsamında 3%, 5% ve 10% zemin eğimleri dikkate alınmıştır. Elde edilen sonuçların karşılaştırılabilmesi adına zemin eğimin dikkate alınmadığı referans betonarme bina için hesaplamalar yapılmıştır. Oluşturulan dört farklı yapı modeli için statik itme ve özdeğer analizleri yapılmıştır. Yapısal modellerin tamamında değişken olarak sadece zemin kat kolon yükseklikleri seçilmiştir. Yapısal analizlere esas olan diğer tüm değerler sabit olarak alınmıştır. Her bir yapısal model için periyot, yer değiştirme, taban kesme kuvvet, elastik ve efektif rijitlik ile hasar durumları için üç farklı hedef deplasman değerleri ayrı ayrı hesaplanmıştır. Her bir yapı modeli için ilk ve son hasar şekilleri elde edilmiştir. Zemin eğiminden dolayı oluşan kısa kolonlar yapının deprem performansını olumsuz olarak etkilemektedir. Zemin eğiminin artmasından dolayı zemin katta yer alan kolon yüksekliklerindeki azalma yapının rijitlik değerlerini arttırmakta, periyot değerlerini azaltıp, yapının sismik kapasitesini arttırmaktadır. Ancak zemin eğiminin fazla olduğu yapı modellerinde daha düşük yük faktörleri altında ilk hasarlar meydana gelmiştir. Oluşan ilk hasarlar eğimden dolayı en düşük yüksekliklere sahip kolonlarda oluşmuştur. Yer değiştirme istem talepleri zemin eğiminin arttığı yapı modellerinde azalmıştır.

Ensuring the safety and stability of buildings during earthquakes is of utmost importance. This can be achieved by assessing the seismic performance of reinforced concrete structures with consideration of design details. This study focused on the seismic behavior of reinforced concrete buildings by comparing the effects of two different types of stirrups, namely those with a 135° angled end-hook shape and straight hooks, with variation of concrete strength. Pushover analysis of a sample building was performed to determine the effect of hook shape on stirrup reinforcement with a constant volumetric ratio for various concrete strength classes. The results of the analysis indicated significant differences in concrete strength and seismic behavior between the two stirrup configurations. The hooked stirrups demonstrated superior energy dissipation capability and ductility, which led to better seismic performance compared to unhooked stirrups across varying levels of concrete strength. To extend the investigation, the study compared the Mander et al., Kent–Scott–Park, and Kappos–Konstantinidis concrete models with different concrete classes (C50-C25-C20-C16-C10). The findings emphasized the importance of stirrup configuration in the design of earthquake-resistant structures. The study concluded that RC structural performance with the 135-degree hooked concrete members exhibited much better behavior of the 90-degree members for the various concrete strength. In this way, it has been revealed the arrangement and detailing of reinforcement in the construction beams and columns improves the governing effect on seismic structural performance.