Serological and histolomorphological investigation of camel bulls testes (Camelus dromedaries) during the rutting and non-rutting seasons.

BACKGROUND: Camels are bred for their milk, meat, wool and hair, transportation, and their excrement as fuel. The seasonal reproduction of camel bull is accompanied by changes in sexual activity, the morphology, and function of the testes. This study aimed to evaluate the seasonal fluctuations in serum testosterone (T) levels as well as total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in the testes of dromedary bulls (Camelus dromedarius) during the rutting and non-rutting seasons. Moreover, the impact of rutting season on the testicular size and histomorphology was also observed. Seventy mature dromedary bulls were divided into a rutting group (n = 35) and a non-rutting group (n = 35). From these bulls, blood samples and testes were collected during the rutting season (October to April) and non-rutting season (May to September) from a local slaughterhouse. RESULTS: All parameters changed significantly during rutting and non-rutting periods in camel bulls. The levels of TAC in testes, and serum T were significantly (P < 0.05) higher in the rutting group than in the non-rutting group. However, testicular MDA was significantly (P < 0.05) lower in the rutting group than in the non-rutting group. TAC was negatively correlated with MDA (r = -0.59, p < 0.01). Moreover, in the rutting group and the non-rutting group, T was positively correlated with levels of TAC (r = 0.66, p < 0.0003). Additionally, testicular size (length, breadth, and thickness) was significantly greater in camels during the rutting season than in camels during the non-rutting season. Moreover, the number and diameter of seminiferous tubules, and spermatogenesis increased during the rutting season, whereas, the collagen content and apoptosis increased during the non-rutting season. CONCLUSION: This study revealed that the rutting normal breeding season (NBS, rutting group) was associated with higher levels of total antioxidant capacity (TAC), T, and spermatogenic activity while the collagen content, concentrations of MDA (the oxidative stress factor) and apoptosis (an outcome of oxidative stress) were lower than those in the low breeding season (LBS, non-rutting group). In addition, the testicular size and seminiferous tubule diameter and number were higher during the NBS.

The development of an eco-friendly cold mix asphalt using wastewater sludge ash.

The aim of this research was to develop a sustainable and ecologically sound, non-traditional cold mix asphalt (CMA) that can be used in the construction industry. This new type of CMA incorporates wastewater sludge fly ash (UFA) and bottom ash (UBA) as a replacement filler for ordinary Portland cement and limestone. Silica fume (SF) was also used as an additional filler. The mechanical and durability characteristics of the new CMAs were examined in terms of indirect tensile stiffness modulus (ITSM), and rutting, fatigue, water and fuel resistance. The results showed that CMA with 2.1% OPC +3.9% UFA at 3 days of age, had ITSM values 11 times that of traditional CMA, while CMA with 2.1% OPC+ 3.3% UFA +0.6% UBA, had ITSM values 5 times that of traditional CMA at 28 days of age. SF activated hydration for both mixes, significantly increasing ITSM. These results indicate that CMA has a comparable mechanical performance to standard Hot Mix Asphalt (HMA) mixtures for use as surface pavement layers. This study offers a novel CMA with improved mechanical performance. It is economically effective and ecologically beneficial, compared to HMA, due to its ability to accommodate wastewater sludge ashes that are often disposed of in landfill sites.

Application of Mobile Mapping System to a Cable-Stayed Bridge in Thailand.

Infrastructures must be inspected regularly to ensure serviceability and public safety. In the case of the Thailand expressway, 200 km of an elevated structure must be inspected once a year. Thailand expressway is an elevated reinforced concrete structure. Visual inspection for defects and structural movements such as excessive deflections, transverse movements, or settlements is a cumbersome process. Therefore, a mobile mapping 3D laser scanning (MLS) which is a high-resolution 3D laser scanner (Trimble MX-8) equipped on a vehicle, was introduced. Scanning was performed on live traffic on the expressway. From MLS, both the structure geometry and pavement point cloud data were obtained. A good agreement between elevations of the Rama XI bridge in Bangkok measured by point cloud data using MLS and by a real-time kinematic survey was obtained. The effect of mesh size on the output by MLS was investigated. It was found that a mesh size of 10 cm reduced the computational effort by 75% when compared to a mesh size of 5 cm. However, the International Roughness Index was reduced by 5%. International Roughness Index (IRI) estimated by MLS was close to the IRI values measured by the profilometer. However, a significant overestimation in the case of rutting depth was observed.

Environment-friendly recycled asphalt pavement design for road maintenance applications.

Potholes are one of the most common road distresses in Kuwait especially after winter season in 2018. Pavement deterioration rate significantly increases as the pavement exposes to moisture. Paving road requires using high-quality materials. This paper aims to investigate the feasibility of using recycled asphalt pavement in hot mix asphalt (HMA) design. Questionnaires and a series of laboratory tests were conducted to analyze the effects of pores on the society and test the recycled and the regular mixtures performance to choose the best option regarding it. Marshal test portrayed that the recycled mixture has a high stability and flow. According to the tensile strength ratio test requirements which set a minimum ratio of 75%, it is recommended to reduce the proportion of recycled aggregate. The Hamburg wheel tracker (HWTD) test proved that the recycled asphalt mixture has a low rutting depth for wet and dry samples compared to the general one. On the other hand, the wet recycled mixture requires a reduction by of 20% to satisfy the specifications. The physical properties for both mixtures were compared, and the voids filled with asphalt (VFA) and voids in mineral aggregate (VMA) of the recycled mixture are lower than those in the regular mixture. The recycled mixture reveals a higher efficiency in saving costs and improving mixtures used for potholes maintenance activities. All the results proved that the mixtures consisting of recycled asphalt are most preferred since they are affordable and perform reasonably well compared to mixtures made of regular asphalt. As a future work, smaller percentages of recycled aggregate should be tested to check the robustness and sustainability of the designed recycled asphalt mixture using different tests such as Hamburg wheel tracker test (wet samples) and indirect tensile strength test. Furthermore, more experiments can be run to test other mix parameters and properties such as durability.

Rutting vocal display in male impala (Aepyceros melampus) and overlap with alarm context.

BACKGROUND: The rutting vocal display of male impala Aepyceros melampus is unique for its complexity among ruminants. This study investigates bouts of rutting calls produced towards potential mates and rival males by free-ranging male impala in Namibia. In particular, a comparison of male rutting and alarm snorts is conducted, inspired by earlier findings of mate guarding by using alarm snorts in male topi Damaliscus lunatus. RESULTS: Rutting male impala produced 4-38 (13.5 ± 6.5) rutting calls per bout. We analyzed 201 bouts, containing in total 2709 rutting calls of five types: continuous roars produced within a single exhalation-inhalation cycle; interrupted roars including few exhalation-inhalation cycles; pant-roars distinctive by a pant-phase with rapidly alternating inhalations and exhalations; usual snorts lacking any roar part; and roar-snorts starting with a short roar part. Bouts mostly started and ended with usual snorts. Continuous roars were the shortest roars. The average duration of the exhalatory phase was longest in the continuous roars and shortest in the pant-roars. The average fundamental frequency (49.7-51.4 Hz) did not differ between roar types. Vocal tract length, calculated by using measurements of the first four vocal tract resonances (formants), ranged within 381-382 mm in all roar types. In the studied male impala, rutting snorts within bouts of rutting calls were longer and had higher values of the upper quartile in the call spectra than alarm snorts produced towards potential danger. CONCLUSIONS: Additional inhalations during the emission of the interrupted and pant-roars prolong their duration compared to the continuous roars but do not affect the fundamental frequency or the degree of larynx retraction while roaring. Alarm snorts are separated from one another by large intervals, whereas the intervals between rutting snorts within bouts are short. Sometimes, rutting snorts alternate with roars, whereas alarm snorts do not. Therefore, it is not the acoustic structure of individual snorts but the temporal sequence and the occasional association with another call type that defines snorts as either rutting or alarm snorts. The rutting snorts of male impala may function to attract the attention of receptive females and delay their departure from a male's harem or territory.

Vocal phenotype of male rutting roars and genetic markers delineate East European red deer (Cervus elaphus) from Central and West European populations.

This study investigates a population of red deer Cervus elaphus, founded by 10 individuals introduced in the nineteenth century from Germany to the Voronezh region of the European part of Southern Russia and then developed without further introductions. We characterize for the first time the vocal phenotype of the Voronezh red deer male rutting calls in comparison with similar data on the Pannonian (native Central European) and Iberian (native West European) red deer obtained by the authors during preceding studies. In addition, we provide for the first time the genetic data on Pannonian red deer. In Voronezh stags, the number of roars per bout (2.85 ± 1.79) was lower than in Pannonian (3.18 ± 2.17) but higher than in Iberian (2.11 ± 1.71) stags. In Voronezh stags, the duration of main (the longest within bouts) roars was longer (2.46 ± 1.14 s) than in Pannonian (1.13 ± 0.50 s) or Iberian (1.90 ± 0.50 s) stags. The maximum fundamental frequency of main roars was similar between Voronezh (175 ± 60 Hz) and Pannonian (168 ± 61 Hz) but higher in Iberian stags (223 ± 35 Hz). Mitochondrial cytochrome b gene analysis of red deer from the three study populations partially supports the bioacoustical data, of closer similarity between Voronezh and Pannonian populations. In contrast, microsatellite DNA analysis delineates Voronezh red deer from either Pannonian or Iberian red deer. We discuss that population bottlenecking might affect the acoustics of the rutting roars, in addition to genotype.

Fatal deer attack in a rutting season.

Animal inflicted fatal or near fatal injuries are well described in the forensic literature, with the most frequently described cases involving dogs, large cats and bears. To our knowledge, a deer inflicted fatality has not been described in the forensic literature previously. This article reports a case of a 64-year-old male, who was found lying in a pool of blood near an enclosure for stags and hinds at the end of October. There were mechanical defects on his jacket and trousers, which appeared to be torn or penetrated, as well as multiple lacerations and stab wounds in different parts of his body. The type and location of the injuries the man had sustained strongly suggested that another person had been involved in the incident that had led to his death. The cause of death was deemed as external exsanguination due to multiple stab wounds to large vessels. After evaluating all of the information regarding the circumstances around the death, the case was classified as a deer attack related fatality, and the manner of death was determined to be accidental. The man was most probably attacked by one of the deer while he was refilling the animal feeder. A substantial increase in the levels of selected hormones, especially testosterone, during the rutting season explains the increased levels of aggression shown by the deer that led to a fatal outcome for the decedent.

Enhancing High-Temperature Performance of Flexible Pavement with Plastic-Modified Asphalt.

Previous studies indicate that traditional asphalt mixtures lack the ability to withstand the stresses caused by heavy traffic volumes under high temperatures. To enhance the rutting resistance of flexible pavement under high levels of temperature and loading, extensive laboratory experiments were carried out. A 60/70 grade bitumen was used as a neat sample for comparison. The study introduced three distinct polymers, polypropylene (PP), low-density polyethylene (LDPE), and acrylonitrile butadiene styrene (ABS), at varying concentrations by weight into the neat bitumen. Initially, conventional tests were performed to evaluate the conventional properties of both the neat and modified bitumen, while aggregate tests assessed the mechanical properties of the aggregates. Subsequently, a Marshall mix design was performed to determine the optimum bitumen content (OBC) in the asphalt mixture. Finally, wheel-tracking tests were performed under a specific load and temperature to investigate the rutting behavior of the modified asphalt mixtures. The results of this comprehensive study revealed that the modified asphalt mixtures displayed improved resistance to rutting compared to the neat asphalt mixture. Furthermore, it was also observed that the LDPE exhibited a superior performance against rutting, followed by the PP and ABS. At polymer contents of 3%, 5%, and 7%, the LDPE achieved reductions in rut depth of 13%, 24%, and 33%, respectively, outperforming both PP- and ABS-modified asphalt. These findings not only enhance our understanding of asphalt behavior under diverse conditions but also highlight the potential of plastic-modified asphalt as an effective solution for mitigating rutting problems in road pavements. By incorporating plastic modifiers into asphalt mixtures, this approach aligns with the principles of sustainable construction by reducing plastic waste while improving pavement durability and performance.

Physics-guided neural network for predicting asphalt mixture rutting with balanced accuracy, stability and rationality.

The prediction of rutting performance of asphalt materials poses a significant challenge due to the intricate relationships between the rutting performance and its influencing factors. Machine learning models have gained popularity to address this challenge by offering sophisticated model structures and algorithms. However, existing models often prioritize model accuracy over stability and rationality. The increasingly complicated model structure may lead to an imbalance between the data and the model, resulting in issues such as overfitting and reduced model applicability and interpretability. In this context, this study proposes a novel modeling framework to predict the rutting performance of asphalt mixture by utilizing autoencoder for feature selection and feedforward neural network for rut depth prediction. Notably, physics information of the selected variables is implemented into the neural network to achieve the appropriate balance of model accuracy, stability, and rationality. The results demonstrate that while maintaining high model accuracy, the implementation of physics information significantly enhances the model's stability and rationality. This framework holds great potential for accurate and reliable predictions of pavement distress by leveraging the complementary strengths of data-driven machine learning and physics-based domain knowledge.

Effect of SARA Fractions on Fatigue Properties of Hard Asphalt.

The fatigue performance of hard asphalt is an important factor that affects the service life of asphalt pavement. In order to comprehensively explore the influence of chemical components on the fatigue performance of hard asphalt, and to eliminate the chemical instability between the microstructure of asphalt from different oil sources, seven kinds of hard asphalt were designed and prepared with saturates, aromatics, resins, and asphaltenes (SARA) extracted from the same hard asphalt. Rheological, time sweep and linear amplitude sweep (LAS) tests were carried out to evaluate the fatigue properties. The results show that the complex modulus of asphalt binds increased rapidly with an increase of asphaltene and resins and that the colloidal structure was strengthened, which would increase the fatigue factor. In the time sweep test, the strength of the colloidal structure significantly affected the fatigue life, and the fatigue life was different under different test stresses. In the viscoelastic continuum damage (VECD) model, the cumulative damage was related to the modulus, while with the increase of asphaltene and resins, the fatigue life showed a trend of first increasing and then decreasing. The linear regression analysis showed that the fatigue life of hard asphalt had a good correlation with strain sensitivity. This study investigated the applicability of different fatigue evaluation methods and revealed the influence of four components on the fatigue properties of hard asphalt. The results provide significant insights in the improvement of the fatigue performance of both hard asphalt and corresponding mixtures.

Modelling reindeer rut activity using on-animal acoustic recorders and machine learning.

For decades, researchers have employed sound to study the biology of wildlife, with the aim to better understand their ecology and behaviour. By utilizing on-animal recorders to capture audio from freely moving animals, scientists can decipher the vocalizations and glean insights into their behaviour and ecosystem dynamics through advanced signal processing. However, the laborious task of sorting through extensive audio recordings has been a major bottleneck. To expedite this process, researchers have turned to machine learning techniques, specifically neural networks, to streamline the analysis of data. Nevertheless, much of the existing research has focused predominantly on stationary recording devices, overlooking the potential benefits of employing on-animal recorders in conjunction with machine learning. To showcase the synergy of on-animal recorders and machine learning, we conducted a study at the Kutuharju research station in Kaamanen, Finland, where the vocalizations of rutting reindeer were recorded during their mating season. By attaching recorders to seven male reindeer during the rutting periods of 2019 and 2020, we trained convolutional neural networks to distinguish reindeer grunts with a 95% accuracy rate. This high level of accuracy allowed us to examine the reindeers' grunting behaviour, revealing patterns indicating that older, heavier males vocalized more compared to their younger, lighter counterparts. The success of this study underscores the potential of on-animal acoustic recorders coupled with machine learning techniques as powerful tools for wildlife research, hinting at their broader applications with further advancement and optimization.

Dynamic mechanical response of hot central plant recycling asphalt pavement considering the rutting deformation of existing structure: pollution reduction and durability promotion.

In the pavement industry, there is a pressing need for the reuse of recycled asphalt pavement (RAP) materials. However, the rutting deformation in existing pavement structures is often overlooked in the design of recycled asphalt pavement, which hinders long-term performance prediction and durability assessment. This study examined the viscoelastic properties and fatigue performance of recycled asphalt mixtures. Different combinations of surface layers with varying RAP contents and binder layers with different rutting damage levels were designed. A 3D-Move Analysis model was used to analyze the dynamic mechanical response of these structures under moving loads. Results showed that the stiffness of recycled asphalt mixture increased with the RAP content, but the fatigue performance decreased by 39.4% when the RAP content reached 50%. Incorporating 50% RAP in the surface layer can reduce the compressive stress caused by vehicle loading, thus reducing the vertical compression strain and permanent deformation of the asphalt layers and the subgrade. However, the surface layer with higher RAP content is exposed to intense alternating tensile and compressive strains, leading to poor fatigue durability. The dynamic mechanical behavior of recycled asphalt pavement structures was found to be significantly impacted by the characteristics of the binder layer. The lower dynamic modulus of the binder layer (e.g., 18 mm rutting depth) can lead to more deformation and an increased risk of fatigue cracking. Moreover, the dynamic performance of mixtures with 0% and 50% RAP in the surface layer is even more affected by changes in the binder layer properties. It is recommended to consider the design of dynamic modulus combinations of existing binder layer materials and surface materials with higher RAP, in order to increase the utilization of RAP for high-grade highways and improve the stress distribution to enhance their durability.

Investigation of Rutting Performance in Geogrid-Reinforced Asphalt by Penetration Test.

Permanent deformation, or rutting, is one of several critical distresses in flexible pavements. This paper introduced a novel experimental method, a penetration test, for asphalt mixtures to quantify the effects of glass fibre geogrids embedded in asphalt under repeated loading. It was found that the evolution of permanent deformation (εp) and its strain rate have three clearly identifiable stages. It was also observed that the presence of the geogrid increased the flow number and the number of cycles to failure significantly compared to control samples. Some of the current εp fitting models were found to be valid for deformation prediction under penetration. In addition, a new simple FN calculation method was also proposed based on strain rate and it showed consistent results. In particular, geogrid type "Grid10", which has smaller aperture size (12.7 mm) had slightly better reinforcement performance regarding the rutting resistance due to its larger contact area. Overall, the test and data analysis method presented in this study could be an important reference for future investigations on geosynthetic-reinforced pavement materials.

A Design Method on Durable Asphalt Pavement of Flexible Base on Anti-Rutting Performance and Its Application.

To solve the durability of flexible base asphalt pavement, especially its anti-rutting problem, a design method on durable asphalt pavement of flexible base on anti-rutting performance was put forward in the paper, based on many experiments and calculations. Firstly, a method that asphalt could be selected according to penetration and the anti-rutting factor of its base asphalt was found, which solved the problem of the asphalt selection of the flexible base asphalt mixture design. Meanwhile, a method of skeleton-density structure gradation design was proposed based on the fractal void ratio of coarse aggregate, fractal volume of fine aggregate in coarse aggregate, penetration, fractal dimension of gradation particle size, and rutting tests, which effectively solved in advance the rutting and fatigue performance of flexible base asphalt mixtures. Then, on the basis of the fatigue damage, a calculation method of fatigue life was suggested, which solved the problem that the fatigue damage of asphalt mixtures rarely considered the combined effects of creep damage and fatigue damage. In addition, a calculation method of rutting was formulated based on vehicle dynamic load and ANSYS 16.0 software. Lastly, the feasibility of the design method on durable asphalt pavement of flexible base on anti-rutting performance was verified combining with the real engineering of a supporting project and several numerical calculations and tests.

Rutting prediction and analysis of influence factors based on multivariate transfer entropy and graph neural networks.

The Rutting prediction model is an essential element of efficient pavement management systems. Accuracy of commonly used predictive model necessitates knowledge of the input parameters that was incorporated and local calibration of the model coefficients. In this paper, a novel rutting prediction model based on multivariate transfer entropy and graph neural networks is proposed for incorporating a limited number of observable inputs, which can accommodate with sufficient prediction performance and generalization to a variety of complex pavement design structure data. The multivariate transfer entropy based graph representation is able to find the significant causality between variables and rutting. The influence factor analysis results confirm the high influence of temperature and vehicle axle load. Several experiments are set up on the Research Institute of Highway Ministry of Transport track (RIOHTrack) dataset for the comparison between the proposed model and the state-of-art prediction models. The result demonstrates that the proposed model is more accurate and robust compared to existing methods on the rutting prediction task.

The rutting model of semi-rigid asphalt pavement based on RIOHTRACK full-scale track.

Semi-rigid asphalt pavement has a wide range of application cases and data bases, and rutting is a typical failure mode of semi-rigid asphalt pavement. The establishment of an accurate rutting depth prediction model is of great significance to pavement design and maintenance. However, due to the lack of perfect theoretical system and systematic research data, the existing rutting prediction model of semi-rigid asphalt pavement is not accurate. In this paper, machine learning and mechanical-empirical model are combined to study the feature selection affecting the rutting evolution and rutting depth model of semi-rigid asphalt pavement. First, the particle swarm optimization random forest model is used to select the important features that affect the evolution of rutting depth. Second, the R-F model based on important features is proposed for the first time, which is compared with modification of rutting model in the Chinese Specifications for Design of Highway Asphalt Pavement (JTG D50-2017) and R-B model based on the improved Burgers model. The results show that the R-F model has more accurate prediction ability and better generalization ability, and it does not need complex data preprocessing and noise reduction. Here, the machine learning method is introduced to analyze the data characteristics, and the R-F rutting depth prediction model framework is innovatively proposed, which greatly improves the applicability and accuracy of the existing model framework.

Rutting Performance Evaluation of BMD Surface Mixtures with Conventional and High RAP Contents under Full-Scale Accelerated Testing.

The balanced mix design (BMD) constitutes a significant step forward in the pursuit of better-performing asphalt mixtures. This approach/framework offers increased innovative opportunities for the proper design and production of engineered asphalt mixtures without the need to strictly adhere to traditional volumetric requirements. The primary objective of this paper is to conduct a comprehensive investigation of the permanent deformation (rutting) behavior of surface mixtures (SMs) with conventional and high reclaimed asphalt pavement (HRAP) contents through full-scale accelerated testing under incremental loading conditions while accounting for the environmental aging effect. HRAP SMs were designed in this study, marking the initial application of Virginia Department of Transportation (VDOT) BMD special provisions, with attempts to incorporate 45% and even 60% RAP. Results showed that all BMD HRAP mixtures exhibited higher rut depths compared to the control mixture, which can be attributed to the inclusion of high binder contents aimed at enhancing cracking resistance. The asphalt pavement analyzer (APA) rut test and the stress sweep rutting tests were performed on mixtures sampled during production. Correlation analysis revealed significant and strong positive correlations between accelerated pavement testing (APT) and the multilevel laboratory rutting performance tests considered in this study. Finally, while acknowledging the limitations and all the assumptions considered in this study, the correlation analysis recommended refining the VDOT BMD APA rut depth threshold by lowering the current limit of 8 mm to 7 mm to ensure good performing mixtures from a rutting point of view.

Infrastructure in the Age of Pandemics: Utilizing Polypropylene-Based Mask Waste for Durable and Sustainable Road Pavements.

When navigating the environmental exigencies precipitated by global pandemics, the escalation of mask waste presents a multifaceted dilemma. In this avant-garde research, we unveil a novel approach: harnessing the sterilized shredded mask residues (SMRs), predominantly composed of 100 wt. % polypropylene, as pioneering modifiers for asphalt. Distinct proportions of SMR (e.g., 3, 6, and 9 wt. %) were judiciously integrated with fresh-virgin base AP-5 asphalt and subjected to an extensive suite of state-of-the-art examinations, encompassing thin-layer chromatography-flame ionization detection (TLC-FID), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and specific rheological metrics. The TLC-FID diagnostic trajectories highlighted the nuanced rejuvenating influence of SMR on the binder, a facet reinforced by a pronounced elevation in the thermodynamic stability index (IC). The FT-IR spectra elucidated SMR's preeminent role as a filler, negating notions of chemical reactivity. The TGA analyses unveiled an elevated thermal onset of degradation, signposting enhanced thermal resilience, whereas the DSC readings illuminated a superior thermal comportment at lower extremities. The SEM evaluations rendered a clearer panorama: there was heightened textural perturbation at escalated SMR incorporations, yet the 3 wt. % concoction showcased an optimal, coherent microtexture symbiosis with asphalt. The rheological scrutinies revealed a systematic trajectory: a diminishing penetration and ductility countered by ascending softening points and viscosity metrics. The coup de maître stemmed from the DSR analyses, unequivocally validating SMR's unparalleled prowess in curtailing rutting distress. This seminal inquiry not only posits a blueprint for refined pavement longevity but also champions a sustainable countermeasure to pandemic-propelled waste, epitomizing the confluence of environmental prudence an d infrastructural fortitude.

Effect of Processed Oil on Asphalt Binder Properties.

This study investigates the effectiveness of processed oil in the modification of PG 64-22 and PG 76-22 by assessing their physical and rheological properties, and multiple comparison was conducted between the two binders. The base binders PG 64-22 and PG 76-22 were blended with processed oil at four different percentages of contents (3%, 6%, 9% and 12% by the weight of the binder) and compared with the control binder in each test. The base and modified binders were artificially short-term and long-term aged using a rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were performed on the modified binders by applying a rotational viscometer (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR). The comparisons and results presented in this study indicate that (1) the processed oil has a significant effect on the binders' viscosity, which changes with respect to the increment of processed oil content. The viscosity of both modified binders decreased with the addition of 3, 6, 9 and 12% processed oil; (2) the performed DSR test showed that the addition of processed oil had a negative effect on the rutting resistance for both binders, since in PG 64-22, G*/Sin δ values decreased by 55, 65, 75 and 83% with the addition of 3, 6, 9 and 12% processed oil, respectively, while a decrement of G*/Sin δ of 24, 45, 58 and 65% with the addition of 3, 6, 9 and 12% processed oil was observed in PG 76-22; meanwhile, the fatigue cracking performance was improved and was found to be effective, while G* Sin δ in PG76-22 decreased by 9, 30, 36, and 52% and in PG 64-22 by 27, 44, 53, and 67% with the addition of 3, 6, 9 and 12% processed oil; (3) the results from the BBR test indicate significant improvement in the thermal cracking properties of the binders. The addition of 3, 6, 9 and 12% processed oil resulted in a decrease in the stiffness of both the PG 64-22 and PG 76-22 binders, with a positive effect consequently being observed on the m-values of the binders.

Evaluation of Effect of Thermoplastic Polyurethane (TPU) on Crumb Rubber Modified (CRM) Asphalt Binder.

Crumb rubber binder with thermoplastic polyurethane (TPU) has been experimented with to characterize the performance properties considering the workability, rutting, fatigue cracking and cracking resistance at low temperatures depending on the temperatures and aging states. Physical and rheological properties were evaluated to proceed with the study by applying Superpave asphalt binder testing and multi-stress creep recovery (MSCR). Based on the targeted experiments, the binder samples were produced at three aging states (original, short-term aged and long-term aged) using a rolling thin film oven (RTFO) and pressure aging vessel (PAV). The results revealed that (i) the addition of TPU into CRM binders has a potential effect on increasing viscoelasticity at the original condition, (ii) CRM binders containing TPU showed improved anti-aging performance based on results of RTFO residues and (iii) the inclusion of TPU made it possible for CRM asphalt binder to improve its fatigue and cracking resistance at low temperature.