Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer

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

Comparison of Effects of Using Geosynthetics and Lime Stabilization to Increase Bearing Capacity of Unpaved Road Subgrade

So many soil improvement methods have been developed in order to increase bearing capacity of superstructure of the road to be constructed on the soft clayey road base soils, decrease settlements, and increase other strength specifications (CBR, k, MR values, etc.). In this paper, lime stabilization of clayey road base soil with high water content and its improvement with geosynthetics (geocell + geotextile) reinforcement and comparisons of these two different improvement methods were made. For this purpose, plate loading experimental comparisons of clayey soil, which had high water content by 10% increasing the optimum water content, were made after it was improved with lime at the rates of 3, 6, and 12%, geotextile reinforcement, geocell reinforcement, geosynthetics reinforcement, and geosynthetics reinforcement + lime stabilization at various rates. It was understood that these improvement methods will not yield sufficient results on clayey soils with high water content on their own, and method of improvement with lime and then reinforcement with geosynthetics yields better results on these types of soils. Only one improvement state among ten different states examined in this study gave the sufficient results for the soil to be used for unpaved roads

Investigation of Geogrid Aperture Size Effects on Subbasesubgrade Stabilization of Asphalt Pavements

The increased use of geogrids in highway pavement subbase layer reinforcement applications has resulted in a need to better understand the soil–geogrid interface properties for the use in analysis and design. For this purpose, a series of laboratory large scale pullout tests was carried out with three different aperture size geogrid samples randomly sampled from a single manufacturer. It was found that geogrids are unique in their pullout performance within pavement subbase layer structure based on their aperture sizes. Analysis indicates a strong relationship between pullout performance and geogrid aperture size of geogrids at moderate normal stress levels. Such findings aid in selection of appropriate geogrid types for subgrade and subbase interface reinforcement purposes. Further experimental analysis was conducted to investigate the wide-width tensile test performance for the same samples used in the pullout tests in this study

The effect of concrete pavement finess modulus on friction loss

Bu çalısmada, beton yol karısımlarında, ince agreganın incelik modülüne bağlı olarak, beton yol yüzeyi sürtünme katsayısının kaybı arastırılmıstır. Üç farklı incelik modülünde (2.2, 2.7 ve 3.15) üç beton karısımı hazırlanmıstır. Üst yüzeyi pürüzlendirilmis beton numuneleri asındırmak için, lastik tekerleğin sabit düsey ve yatay yük uyguladığı bir düzenek kullanılmıstır. 0, 1.000, 5.000, 25.000 ve 100.000 tekerlek geçis sayılarında, beton numunelerin yüzey sürtünme katsayıları ?ngiliz sürtünme pandülü ile ölçülmüstür. Test sonuçlarına göre, incelik modülü ile sürtünme kaybı arasında kuvvetli bir iliski ortaya çıkmamıstır.In this study, the friction loss of concrete roads depending on the finess modulus was investigated. The three main mixes were prepared according to three types of finess modulus (2.2, 2.7, 3.15). A special designed abrasion test setup consisted of tire applying a constant lateral and vertical load on a textured concrete surface has used. The friction coefficienst of concrete surfaces were measured with British friction pandul under 0, 1000, 5000, 25000, and 100000 tire passes. The test results showed that there is no strong relationship between fine aggregate fineness modulus and friction loss

The effect of concrete pavement finess modulus on friction loss

Bu çalışmada, beton yol karışımlarında, ince agreganın incelik modülüne bağlı olarak, beton yol yüzeyi sürtünme katsayısının kaybı araştırılmıştır. Üç farklı incelik modülünde (2.2, 2.7 ve 3.15) üç beton karışımı hazırlanmıştır. Üst yüzeyi pürüzlendirilmiş beton numuneleri aşındırmak için, lastik tekerleğin sabit düşey ve yatay yük uyguladığı bir düzenek kullanılmıştır. 0, 1.000, 5.000, 25.000 ve 100.000 tekerlek geçiş sayılarında, beton numunelerin yüzey sürtünme katsayıları ingiliz sürtünme pandülü ile ölçülmüştür. Test sonuçlarına göre, incelik modülü ile sürtünme kaybı arasında kuvvetli bir ilişki ortaya çıkmamıştır.In this study, the friction loss of concrete roads depending on the finess modulus was investigated. The three main mixes were prepared according to three types of finess modulus (2.2, 2.7, 3.15). A special designed abrasion test setup consisted of tire applying a constant lateral and vertical load on a textured concrete surface has used. The friction coefficienst of concrete surfaces were measured with British friction pandul under 0, 1000, 5000, 25000, and 100000 tire passes. The test results showed that there is no strong relationship between fine aggregate fineness modulus and friction loss

Banjarmasin şehrinden diğer şehirlere olan ulaşım seçeneklerinin analizi: Ayrışık logit model

Son yıllarda Banjarmasin şehrinde her alanda, özellikle de ulaşım alanındaki aktiviteler oldukça artmıştır. Şehirdeki yolcular tarafından kullanılan seçilmiş güzergaha göre ulaşım türü tercihi davranışının gözlemlenmesine ihtiyaç vardır. Bu çalışmada ayrışık logit model, şehir merkezinden diğer yerleşim birimlerine olan en uygun şehirlerarası ulaşım türünü bulmak için kullanılmıştır. Ulaşım süresi, ulaşım harcamaları, cinsiyet farklılıkları, meslek grupları ve yolcu gelirleri gibi gözlem parametreleri ulaşım şeklinin tanımlanmasında kullanılmıştır. Karayolu, deniz, nehir ve hava taşımacılığı da geliştirilen bu modele dahil edilmiştir. Araştırma verileri, Banjarmasin şehrinden çıkan trafiğin çıkış noktası olarak altı adet- yerleşim yerinde elde edilmiştir. Bu model kullanılarak her bir parametrenin etkisinin belirlenmesi ve gelecekteki ulaşım türleri için karar verilmesi mümkün olmuştur. Bulunan bu ulaşım türleri uzun mesafeler için ulaşım sistemi geliştirilmesinde girdi verileri olarak kullanılmıştır.In recent years, Banjarmasin city activities have increased in all areas especially in transportation field. There is a demand on observation mode choice behaviour according to chosen route used by the city passengers. In this research, disaggregate logit model was utilized to find the optimum transportation mode which described intercity transport departing from downtown city. Observation parameters such as travel time, cost, gender/sex, occupation, and income were considered in defining the best transportation mode. Highway, sea, river, and air transportation mode routes were also included in the model. The survey data was obtained in six locations as the gateway for outgoing traffic from Banjarmasin. By using the model it was possible to describe the influence of each parameters and make decisions for future modes. The found modes were used as input data in developing transportation system for long distances

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