Sürdürülebilir Kalkınma Amaçları
Yayınlar
- 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 Erişim2020Beton Yol Uygulamalarında Derz Türlerine Göre Düşey Deplasman Oluşumlarının İncelenmesi ve Maliyet Analizi: Trabzon-Rize Örneği
Akpinar, Muhammet Vefa; Seferoğlu, Mehmet Tevfik; Güneş Seferoğlu, Ayşegül; Çelik, Muhammet
Türkiye'de beton yolların kullanımı her geçen gün artmaktadır. Özellikle Doğu Karadeniz Bölgesi'nde 10.000 km'nin üzerinde beton yol bulunmaktadır. Bu çalışmada, Trabzon ve Rize İllerinde yapılan beton yol uygulamaları incelenerek yaygın olarak kullanılan kaplama kalınlığı ve beton basınç dayanımı belirlenmiştir. Karadeniz Teknik Üniversitesi Hızlandırılmış Yol Tesisinde örnek kaplama modeli hazırlanmış ve gerçek trafik yüklemeleri altında beton kaplamaların düşey deplasman değişimleri incelenmiştir. Farklı derz türleri (hasır donatılı yarım derz, donatısız yarım derz, dolgulu tam derz ve dolgusuz tam derz) kullanılarak fayda ve maliyet analizi yapılmıştır. Elde edilen verilere göre, derzlerin yarım derz olması ve kaplamada donatı kullanılması, donatısız yarım derzlere göre 1.3 kat, dolgulu tam derze göre yaklaşık 4 kat, dolgusuz tam derzlere göre ise yaklaşık 9 kat daha az düşey deplasman oluşmasını sağlamaktadır. Ayrıca yapılan maliyet analizlerine göre kaplamalarda hasır donatının bulunması, beton kaplama maliyetine km’de 38.002,76 TL (%11,6) fiyat farkı oluşturmaktadır. Bu bilgiler ışığında, beton kaplamalarda yarım derz yapılmasının ve hasır donatının kullanılmasının kaplama derz bölgelerindeki faydasına oranla maliyetinin oldukça düşük olduğu sonucuna ulaşılmıştır. Ayrıca mevcut tam derzli beton yollarda %7'lik ilave bir maliyet ile derzlerin içinin bitüm esaslı dolgu malzemesi ve kauçuk levhalarla kaplanmasının, düşey deplasman değerlerini en az yarı yarıya azaltılabileceği ve bu sayede kaplama ömrünün uzatılabileceği tespit edilmiştir.
- 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.
- MakaleYayıncıda açık erişim2019Investigating the mechanical behavior of reclaimed asphalt pavement (RAP) bases in large scale test box
Seferoğlu, Ayşegül Güneş; Seferoğlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The objective of this research was to assess the elastic deformations and permanent strains of reclaimed asphalt pavement (RAP) material as a base layer when it is treated or untreated with pozzolanic cement under cyclic loads. A large-scale cyclic plate loading testing (CPLT) device was developed for studying the mechanical characteristics of pavement base layer. The laboratory test results indicated that when the RAP percentage of the mixtures increased, elastic deformations and permanent strains increased, but the opposite was true when the cement percentage increased. It was concluded that 100% RAP material can be used in base layers with 3% pozzolanic cement. The obtained deformation values and strain rates can be used as reasonable default design input values by pavement designers when using RAP as a substitute for natural aggregate base layers.
- BildiriYalnız künye2018Reducing Urban Heat Islands by Developing Cool Pavements
Akpinar, Muhammet Vefa; Sevin, Sedat; Nizetic, S; Papadopoulos, A
- BildiriYalnız künye2018Comparison of Asphalt and Concrete Pavement Solar Reflectance
Akpinar, Muhammet Vefa; Sevin, Sedat; Nizetic, S; Papadopoulos, A
- BildiriYalnız künye2018Urban Heat Island Effects of Concrete Road and Asphalt Pavement Roads
Akpinar, Muhammet Vefa; Sevin, Sedat; Nizetic, S; Papadopoulos, A
- MakaleAçık Erişim2018Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer
Seferoǧlu, Ayşegül Güneş; Seferoǧlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The purpose of this research was to investigate the effects of recycled asphalt pavement (RAP) and cement content on the permeability and bearing capacity characteristics of aggregate base courses. Mixtures containing untreated RAP ranging between 0 and 100 percent and 1, 2, and 3% cement-treated RAP were subjected to laboratory tests (bitumen content, sieve analysis, modified proctor, soaked California bearing ratio (CBR), and constant-level permeability tests). The results showed that, as the RAP percentage in the mixture increased, CBR values decreased considerably. Moreover, there is a linear increase in the CBR values with cement treatment. Optimum moisture contents (OMC) and maximum dry densities (MDD) showed a decreasing trend. Increasing the cement percentages in 100% RAP blend increases the OMC and MDD values. The permeability of RAP showed a decrease as the percentage of RAP and cement increased in blends. The study showed that the CBR value of the 20% RAP blend is also obtained in the 100% RAP/3% cement-treated blend. Thus, it has been understood that cement is a suitable material in order to increase the use of RAP. In addition, the increase in the percentage of RAP and cement made the base course more impermeable.
- MakaleYalnız künye2018Experimental study on cement-treated and untreated RAP blended bases: Cyclic plate loading test
Seferoğlu, Ayşegül Güneş; Seferoğlu, Mehmet Tevfik; Akpinar, Muhammet Vefa
The asphalt surrounding the reclaimed asphalt pavement (RAP) aggregates decrease the performance characteristics of road layers. RAP material increases the permanent deformation potential of road layers under the traffic load. In this study, the performances of RAP-VA (Virgin aggregate) mixtures was tested using cyclic plate loading test by adding pozzolanic cement into mixtures in order to use RAP material at the rate of 100% and to minimize the permanent deformation in plant-mix base courses (PBC). The permanent surface deformations of base course were measured at different points throughout 100 loading cycles and all of the measurements were compared to that of base course prepared from 100% VA. The effect of RAP/cement rate of mixtures on the permanent deformations was examined and it was determined that the increase in RAP rate increased the permanent deformations but cement significantly decreased it. Moreover, considering the material costs of mixtures, the cost analysis was performed and the profit margins that using RAP and cement offers to constructors were computed.
- MakaleAçık Erişim2017Effects of fine aggregate abrasion resistance and its fineness module on wear resistance of Portland cement concrete pavements
Karpuz, Orhan; Akpinar, Muhammet Vefa; Aydin, Metin Mutlu
In this research, effects of fine aggregate abrasion resistance and its fineness module on wear resistance of Portland cement concrete pavements studied. Concrete samples included fine crushed limestone aggregate, fine crushed limestone-basalt mixture, and fine crushed basalt aggregate. The study results showed that LA abrasion rate of 30 % or less of fine aggregates would be necessary for long lasting concrete roads. Furthermore, it was found that fine aggregate's fineness module of 3.15 will significantly increase concrete road surface's wear resistance. As the fine aggregate's fineness module value increased from 2.2 to 3.15, the concrete's wear amount decreased to 15.5 %. Study findings also showed that using basalt aggregates instead of widely used limestone aggregates, will significantly increase pavement concrete wear resistance.