Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Kayseri’de otobüs ve tramvay hizmet kalitesi: Yolcu memnuniyetinin karşılaştırmalı bir analizi
Seferoglu, Aysegul Gunes; Polat, Fatih
Bu çalışma, Kayseri ilinde toplu taşımada kullanılan otobüs ve tramvay hizmetlerinin yolcular tarafından algılanan hizmet kalitesini değerlendirmek ve karşılaştırmak amacıyla gerçekleştirilmiştir. Çevrimiçi olarak uygulanan anket çalışması, demografik bilgiler ve hizmet kalitesi algısını ölçen 20 maddeden oluşmaktadır. Verilerin analizi SPSS 22.0 programı kullanılarak gerçekleştirilmiş; bağımsız grup t-testi, Levene testi ve tek yönlü ANOVA yöntemleri uygulanmıştır. Sonuçlara göre, tramvay kullanıcıları genel memnuniyet düzeyinde otobüs kullanıcılarına göre daha yüksek puan vermiştir. Tramvayda en yüksek memnuniyet, zamanında gelme ve ücret ödeme kolaylığı) alanlarında gözlenirken, doluluk oranı ve koltuk konforu gibi konularda memnuniyet daha düşüktür. Otobüs kullanıcıları genel memnuniyet açısından daha düşük puanlar vermiş; ancak ödeme kolaylığı ve alternatif hat bulma gibi alanlarda nispeten olumlu görüş bildirmiştir. Koltuk konforu ise en düşük memnuniyet alanı olmuştur. Demografik değişkenlerden sadece medeni durum ve eğitim düzeyine göre anlamlı fark bulunmuştur. Genel olarak, tramvay hizmetleri daha yüksek kalite algısı yaratmakta; ancak her iki sistemde de kapasite, sürücü davranışları ve planlama alanlarında iyileştirme gereksinimi ortaya çıkmıştır.
- MakaleYalnız künye2022Investigating the Influence of Joint Reinforcements of Portland Cement Concrete Slabs Under Asphalt Concrete Overlays on Vertical Deflections Using Accelerated Pavement Testing
Seferoglu, Mehmet Tevfik; Seferoglu, Aysegul Gunes; Çelik, Muhammet; Akpinar, Muhammet Vefa
Joint gaps between slabs in underlying Portland cement concrete (PCC) pavements are critical factors in the life span of asphalt concrete (AC) overlays. Therefore, being informed about the vertical deflections that may occur around the joints is important. In this study the joints were reinforced with three different materials: ethylene propylene diene monomer (i.e., rubber joint filler [RJF] reinforcement), bitumen-based sealant (i.e., rubber plate [RP] reinforcement), and steel plate (SP) (i.e., SP reinforcement), to limit the vertical movement of the underlying PCC. Tests were conducted at the accelerated pavement testing facility for two different AC overlay thicknesses, 50 mm and 100 mm, during 100,000 passages to investigate the influence of AC overlay thickness variations on slab vertical deflections and to also evaluate types of joint reinforcement on slab vertical deflections. For 50-mm thick AC overlay, the most effective joint reinforcements to prevent deformations caused by loading were RP, RJF, and SP; for a 100-mm thickness, this was determined to be RJF, SP, and RP, respectively.
- MakaleAçık Erişim2021Evaluation of Load-Transfer Efficiency of Steel Mesh Reinforced Contraction Joints in Concrete Pavement: Accelerated Pavement Test and FE Analysis
Celik, Muhammet; Seferoglu, Mehmet Tevfik; Akpinar, Muhammet Vefa; Nasery, Mohammad Manzoor; Seferoglu, Aysegul Gunes
Transverse contraction joints are by far the most common type of joint in jointed plain concrete pavements. Early loading of contraction joints can create a weakened vertical plane and later grow as a full-depth crack. In this study, load transfer efficiency (LTE) of steel mesh reinforced transverse contraction joints were studied at accelerated pavement tests (APT). 3D finite element (FE) model of jointed plain concrete pavement (JPCP) was developed to study deflections and crack propagation in just under the joint of the concrete pavement. The APT tests were focused on the LTE values before and after the crack initiation under the contraction joint region. Experiments were performed on three slabs in which two of these slabs were prepared without reinforcement and one of them was reinforced with steel mesh. Data generated by APT was used for verification of crack propagation modeling in the finite element analysis. Steel mesh reinforced slab gave the lowest vertical deflections (51μm) and highest LTE (91.56%). The LTE value in the reinforced slab after 25,000 passes was 13.63% higher than the average of unreinforced slabs. The findings suggest that the load transfer efficiency was found to be a complex parameter and should be interpreted together with average displacement values when contraction joints are evaluated at early traffic loadings.
- MakaleAçık Erişim2020Plent-miks temel tabakası yapımında kazınmış asfalt kaplama (RAP) malzemesi kullanımı ve ekonomik analizi
Seferoglu, Aysegul Gunes; Seferoglu, Mehmet Tevfik; Akpınar, Muhammet; Çelik, Muhammet
Bu çalışmanın amacı, Karayolu Teknik Şartnamesi (KTŞ) kriterlerine göre tasarımı yapılacak olan bir plent-miks temel (PMT)tabakası için kullanılabilir kazınmış asfalt kaplama (RAP) malzemesi oranlarına bağlı olarak elde edilecek mali faydalarınbelirlenmesidir. Tüm RAP katkılı karışımların fayda-maliyet analizleri yapılarak PMT tabakası yapımı ve malzemelerin nakliyeharcamaları göz önüne alındığında, RAP malzemesinin hangi uzaklıktan getirilmesi durumunda ekonomik bir uygulama olacağıaraştırılmıştır. Çalışma neticesinde RAP malzemesinin %100 oranında PMT tabakalarında kullanımının çimento takviyesi ilemümkün olduğu ve doğal agrega (DA) yerine kullanılması durumunda %16’nın üzerinde kâr sağladığı belirlenmiştir. RAPmalzemesinin, PMT Tip-1 tabakası için doğal agregaya alternatif ve maliyet açısından daha ekonomik bir malzeme olduğusonucuna varılmıştır.
- MakaleAçık Erişim2020Effect of filler percentage of recycled asphalt pavement (RAP) materials on CBR performance and cost analysis
Seferoglu, Aysegul Gunes; Seferoglu, Mehmet Tevfik; Akpinar, Muhammet Vefa; Çelik, Muhammet
Recycled asphalt pavement (RAP) materials are an alternative to natural aggregate (NA) because they reduce environmental pollution and provide energy and cost savings. In many countries abroad, the usage of RAP materials in road pavement layers are permissible at certain rates. However, the mechanical properties of RAP materials are dependent on; the materials are derived from the in which pavement layer, the service life and construction characteristics of the road it is milled, the properties of the materials used (bitumen and aggregate) in the layer and the characteristics of the milling machine. In this study, two types of RAP materials (RAP(1) and RAP(2)) obtained from the degraded wearing layers of two different roadway using milling machine were mixed with NA in different rates (0%, 15%, 30%, 45%, 60%, 100%). Some of the characteristics of the mixtures were examined with reference to 100% NA mixture values by performing laboratory tests such as bitumen ratio, sieve analysis, modified proctor and California bearing ratio (CBR) on the mixtures obtained. According to the results, maximum rates of RAP(1) and RAP(2) which can be used in plant-mix base type-1 layer as an alternative material to NA is determined according to Turkey Highway Technical Specification. In addition, in the case of using RAP materials, the profit rates of material costs to be reduced by the reduction of the need for NA material are also determined by cost analysis.
- MakaleYalnız künye2020Economic Analysis of the Use of Reclaimed Asphalt Pavement (RAP) Materials in Plant-Mix Base Courses
Seferoglu, Aysegul Gunes; Seferoglu, Mehmet Tevfik; Akpinar, Muhammet Vefa; Çelik, Muhammet
The aim of this study is to determine the financial benefits to be gained based on the percentages of reclaimed asphalt pavement (RAP) material suitable for use in plent-mix courses (PBCs) to be designed according to the specification of Turkey Department of Transportation. Cost analysis of all RAP mixtures were made considering the construction of the plant-mix base course and the transportation costs of the materials, it was researched that the use of RAP would be an economical application in terms of how far the RAP material was taken. As a result of the study, it has been determined that the use of 100% RAP material in PBC is possible with cement reinforcement and it provides a profit of more than 16% in terms of costs in case of using virgin aggregate (VA) instead. RAP material is an alternative to virgin aggregate and is a more economical material in terms of cost.