The primary aim of this study is to predict the Marshall stability and flow values of hot-mix asphalt samples prepared according to the Marshall design method using regression-based machine learning algorithms. To overcome the limited number of experimental observations, synthetic data generation was applied using the Conditional Tabular Generative Adversarial Network (CTGAN), while the structural consistency of the generated data was validated through Principal Component Analysis (PCA). Two datasets containing 17 physical and mechanical input variables were analyzed, and multiple regression models were compared, including Extra Trees, Random Forest, Gradient Boosting, AdaBoost, and K-Nearest Neighbors. Among these, the Extra Trees Regressor consistently achieved the best results with near-perfect accuracy in flow predictions (MAE ≈ 4.06 × 10⁻¹⁵, RMSE ≈ 4.97 × 10⁻¹⁵, Accuracy ≈ 99.99%) and high performance in stability predictions (MAE = 109.52, RMSE = 150.67, accuracy = 90.45%). Furthermore, model interpretability was ensured by applying SHapley Additive Explanations (SHAP), which revealed that parameters such as softening point, VMA, penetration, and void ratios were the most influential features. These findings demonstrate that regression-based ensemble models, combined with synthetic data augmentation and explainable AI methods, can serve as reliable and interpretable tools in asphalt mixture design.

In composite reinforced concrete elements formed by concrete and rebar, only if these two materials work together, reinforced concrete elements can fully function. The significant factor that will ensure working together is the bond strength, which is called adherence. The higher the value of this force, the harder the rebar is to pull out from the concrete. In this experimental study, the effect of concrete additives and aggregate type on the bond strength and the amount of elongation of the reinforcement without stripping from the concrete was investigated. For this purpose, 28-day compressive strength and adherence force and reinforcement elongation amounts of the concrete mixtures produced by using mineral, chemical and fiber additives for two different aggregate series, crushed stone and gravel, and two different cement dosages, were observed. In addition, by using 3 different rebar in terms of diameter and surface properties, the effect of these properties on concrete-rebar adherence was revealed. As a result of the study, the use of crushed stone aggregate, hyperplasticizer additive, mineral additive and ribbed rebar with 18mm diameter increased the bond strength compared to the reference samples.

Visibility problems occur on highways that are not sufficiently illuminated at night, endangering traffic safety. Phosphor material, which has a natural glow feature under ultraviolet (UV) light, is planned to increase road visibility in areas with inadequate lighting. Phosphor powder (PP) was used in four different percentages (25%, 50%, 75%, and 100%) as fillers in hot mix asphalt (HMA), reduced to filler size. Asphalt specimens were prepared using a super pave gyratory compactor and super pave volumetric mixture design. Compacted specimens were exposed to artificial 12V UV light for 10-minute intervals in a dark room, and UV light absorption was observed. Visibility analyses were performed on the specimens by taking high-resolution photos with long exposure from a distance of approximately 30 cm from the asphalt specimen using a professional camera. According to the analysis results, the visibility values increased by 200.4%, 378.5%, 538.1%, and 728.5% compared to the reference specimen for substitution rates of 25%, 50%, 75%, and 100%, respectively. Experiments were conducted to determine the behavior of the specimens prepared as phosphorus substitutes in the mixture. After selecting the optimum binder contents, the modified Lottman test procedure was applied to measure the specimens' strength values and moisture sensitivity prepared at optimum ratios. The indirect tensile test results show that the 25% PP-substituted specimen had a better strength value. The tensile strength ratio (TSR) value, the ratio of dry and wet tensile stresses, was determined to have minor moisture sensitivity in the 50% PP-substituted specimen. HWTT was applied to the specimen containing 50% PP content, which exhibited the best TSR ratio, resulting in improved rutting performance compared to the reference specimen.

En tr Thanks to the technological advances, asphalt production temperatures can be lowered and performance mixes similar to hot mixes can be obtained. The trend of lowering asphalt production temperatures and the popularity of materials recycling are gradually increasing due to the negative environmental effects caused by the heating of hot mix asphalt materials, that is, aggregate and bitumen at high temperatures. Recycling with foam bitumen method, applied using foam bitumen and recycled / natural aggregate is a method that has environmental and economic advantages. The first step to prepare a suitable mixture with foam bitumen is to determine the most ideal foaming properties (expansion ratio and half life) of the bitumen to be used in the mixture. For this reason, foaming properties of different asphalt cements are determined experimentally. In addition, the foaming properties of bitumens used in experiments were modeled using Fuzzy Logic and ANFIS methods and the results were compared with the experimental data. In the light of the data obtained, it was concluded that the use of all bitumen used for different foaming water percentages provides the minimum foaming properties recommended in the literature and the estimation methods used support experimental data with similar results. Teknolojik gelişmeler sayesinde asfalt üretim sıcaklıkları düşürülerek sıcak karışımlara benzer performanslı karışımlar elde edilebilmektedir. Sıcak karışım asfaltların malzemelerinin yani agrega ve bitümün yüksek sıcaklıklarda ısıtılması nedeniyle yarattıkları olumsuz çevresel etkiler, üretim maliyetlerinde meydana gelen sürekli artış ve hammadde kaynaklarındaki azalma nedenleriyle asfalt üretim sıcaklıklarının düşürülmesi eğilimi ve malzemelerin geri kazanımının popülerliği giderek artmaktadır. Köpük bitüm ve geri kazanılmış/doğal agrega kullanılarak uygulanan köpük bitümle geri kazanım yöntemi, çevresel ve ekonomik olarak avantajları olan bir yöntemdir. Köpük bitümle uygun bir karışım hazırlayabilmek için ilk aşama, karışımda kullanılacak bitümün en ideal köpürme özelliklerinin (genleşme oranı ve yarılanma süresi) doğru şekilde belirlenebilmesidir. Bu nedenle çalışmada, farklı asfalt çimentolarının köpürme özellikleri deneysel olarak belirlenmiştir. Ayrıca deneylerde kullanılan bitümlerin köpürme özellikleri Bulanık Mantık ve ANFIS yöntemleri kullanılarak modellenmiş ve sonuçlar deneysel olarak elde edilen verilerle kıyaslanmıştır. Elde edilen veriler ışığında kullanılan tüm bitümlerin farklı köpürtme su yüzdeleri için kullanımlarının literatürde önerilen minimum köpürme özelliklerini sağladığı ve kullanılan tahminleme yöntemlerinin benzer sonuçlarla deneysel verileri desteklediği sonucuna ulaşılmıştır.

Today, due to the increasing construction activities, the evaluation of waste materials has also accelerated. Recycling concrete and road materials provides environmental benefits as well as economic benefits. In this experimental study, it was aimed to use the scraped asphalt pavement as aggregate in the concrete mix. Different proportions of limestone, basalt and scraped asphalt were used as aggregates in the produced concrete samples. CEM I 42.5 R type cement and a certain amount of replacement fly ash were used as binder, and a polycarboxylate based chemical additive was used to ensure easy workability and appropriate molding of the concrete. Pressure test was applied on the produced samples, and the results showed that the use of scraped asphalt material as aggregate reduces the compressive strength of the concrete, but its use in appropriate proportions can be promising.

The reuse of Reclaimed Asphalt Pavement (RAP) in road construction has become increasingly prevalent due to its potential environmental and economic benefits. The aging characteristics of RAP, particularly the degradation of its bitumen content, are critical for evaluating its suitability for future applications. The aging process is influenced by various meteorological factors, including solar radiation, temperature fluctuations, and precipitation. This study investigates the impact of these factors on the properties of bitumen in RAP, focusing on a pavement constructed between 2002 and 2005. After eight years of service, the pavement was milled and the material was stored in a stockpile for an additional eight years. The bitumen properties, specifically penetration and softening point, were measured at regular intervals over the 16-year period. Cumulative meteorological data, including temperature, solar radiation, and precipitation, were recorded and analysed in relation to the observed aging effects on the bitumen. The results demonstrated a linear correlation between the cumulative meteorological conditions and the degree of bitumen aging. Increased exposure to solar radiation and temperature fluctuations accelerated the aging process, while prolonged periods of precipitation appeared to have a moderating effect. These findings suggest that both the duration and intensity of exposure to specific environmental conditions must be considered when assessing the viability of using RAP in future pavement construction.