The global rise in temperature and the desert climatic conditions prevalent in Middle Eastern countries have exacerbated rutting distress in heavily trafficked highways. Conventional asphalt binders with a high-temperature performance grade (PG 70) have proven inadequate under such extreme conditions, necessitating the development of modified binders with enhanced high-temperature performance. While polymer modification using styrene-butadiene-styrene (SBS), an elastomeric polymer, and ethylene-vinyl acetate (EVA), a plastomeric polymer, has been widely studied, limited research provides a direct comparison of their effectiveness at both the binder and mixture levels under extremely high-temperature conditions. This study addresses this gap by evaluating SBS and EVA at 2%, 4%, and 6% by weight of asphalt cement, with a focus on their rheological, chemical, and mechanical properties. At the binder level, properties examined included the physical properties: penetration, softening point, viscosity, mass loss due to aging, storage stability, and specific gravity. The Dynamic Shear Rheometer (DSR) was used to assess the high-temperature performance grade (PG) and conduct Multiple Stress Creep Recovery (MSCR) tests. The results revealed that SBS significantly enhanced high-temperature performance, with 4% SBS and 6% SBS achieving PG 100, compared to PG 70 for both the unmodified and EVA-modified binders. At the most critical testing temperature of 76 °C and the highest stress level of 3.2 kPa, SBS-modified binders exhibited the lowest non-recoverable creep compliance (Jnr) and the highest elastic recovery (R), significantly outperforming EVA-modified binders and the reference binder (RB). At the mixture level, dynamic creep testing confirmed the ranking of asphalt mixes in terms of resistance to permanent deformation, with the following order: 4% SBS > 6% SBS > 6% EVA > 4% EVA > 2% SBS > 2% EVA > unmodified mix. These results, further supported by ANOVA analysis, indicate that SBS-modified mixtures exhibited superior rutting resistance compared to EVA-modified and unmodified mixes. This study provides quantitative insights into the comparative performance of SBS and EVA in extreme hot climatic tempertures, reinforcing the superior effectiveness of SBS in enhancing high-temperature properties. Consequently, SBS emerges as the more suitable modifier for regions experiencing extreme hot climatic conditions. Field validation is recommended to confirm these laboratory findings in real-world applications.
The aim of this research is to identify the effectiveness of thinking skills in developing the life skills of the students of the first Academic year, particularly the differences in life skills according to the variable of study specialization (human-scientific). To achieve the research objectives, the life skills scale was constructed on the classification of (WHO). The psychometric properties of the scale were examined. The validity of the scale, which is the final form of (60) items, was valid for measuring the life skills. The scale was then applied to the research sample of (112) students of the first year of the University of Bisha. The SPSS program processed statistical analysis. Resul
... Show MoreThe game of volleyball requires the formation of new motor responses, which in turn requires special physical characteristics in the performance of that skill, and the correct and accurate performance during the performance of the skills of passing from the top and smash serve in volleyball cannot be developed or improved without a good level of accuracy and what is required to perform the movements in terms of responses to the defense and attack movements. Therefore, the researchers decided to identify the type of relationship between the motor response speed with the performance accuracy of the skills of passing from the top and the smash serve in volleyball. The research aims to: 1. Identifying the motor response speed of fourth-stage s
... Show MoreResearch aims to identify the immediate impact of the announcement of mergers in the stockholders and the feasibility of gain abnormal return and benefiting from asymmetric information during the announcement that unite 30 days before the announcement of the merger, and announcement day, and 30 days after the announcement of the merger. It was the largest and most important mergers and acquisitions pick that occurred during the global financial crisis, specifically in health care/pharmaceutical industry, Pfizer and Wyeth merger with Novartis acquisition on Alcon. search has adopted three hypotheses: the first hypothesis that ((achieves the target company's shareholders positive abnormal return (or negative) during and befor
... Show MoreThe high carbon dioxide emission levels due to the increased consumption of fossil fuels has led to various environmental problems. Efficient strategies for the capture and storage of greenhouse gases, such as carbon dioxide are crucial in reducing their concentrations in the environment. Considering this, herein, three novel heteroatom-doped porous-organic polymers (POPs) containing phosphate units were synthesized in high yields from the coupling reactions of phosphate esters and 1,4-diaminobenzene (three mole equivalents) in boiling ethanol using a simple, efficient, and general procedure. The structures and physicochemical properties of the synthesized POPs were established using various techniques. Field emission scanning elect
... Show MoreAn experimental and theoretical investigation of three phase direct contact heat transfer by evaporation of refrigerant drops in an immiscible liquid has been carried out. Refrigerant Rl2 and R134a were used for the dispersed phase, while water and brine were the immiscible continuous phase. A numerical analysis is presented to predict the temperature distribution throughout the circular test column radially and axially is achieved. Experimental measurements of the temperature distribution have been compared with the numerical results and are discussed .A comparison between the experimental and theoretical results showed acceptable agreement and applicability of the derived equations. Comparison with other related work showed similar beh
... Show MoreThis study was carried out in Artificial Insemination Center of Iraq to revealed FMD disease effect on some seminal attributer parameters of 14 imported Holstein bulls divided to three groups according to different reproductive efficiency (four High, five medium and five weak). Results showed that FMD disease had significant (P < 0.05) adverse effect on most seminal attributer parameters, mass, individual motility and sperm concentration / ml during post disease in first of two, four, all months of high, medium and weak semen quality bulls respectively .but semen volume didn’t influenced significantly with this disease. So semen collection should be suspended until resume normal fertility of sperm, after two, four month of high and
... Show MoreAbstract
The research aims to identify the strategic leadership and its role in activating the Organisational Performance, which is an analytical study of the views of the heads of scientific departments at General Authority of groundwater researcher's quest focused towards building a theoretical framework suitable for strategic leadership and performance Organisational and itُs dimensions.To achieve the aims of the research is designed to identify the researcher included (35) items to collect the raw data from the research sample consisting of 33 of the heads of departments. Data was collected by questionnaire, field visits, interviews and some official documents to complete the search data. It has also been used a numb
... Show MoreThe postmodern ideas and concepts have produced social, political and economic variables that have been affected by wars, crises, the role of globalization and the information revolution. They have created many variables in concepts and great variables in technological, artistic and cultural innovations. All these changes have contributed to changing the form of the theatrical show aesthetically and intellectually, which cast a shadow over the nature of the actor's performance who has become more demanding to change his performance and to find the mechanisms and new nature of work governing him corresponding to those variables and this prompted the researcher to adopt the subject (the performance variable of the actor's techniques in pos
... Show MoreThe services provided by the municipal institutions of the basic things needed by the man in his daily life and the evolution of cities basically depends on these services and therefore has paid most of the world's attention to this vital facility and give him the biggest concern for the welfare of the citizens, as is the research problem that there is no program scrutiny to evaluate the performance of municipal institutions contribute to measuring the efficiency and effectiveness of the services provided and was based on research on the premise that the preparation of the existence of audit program to evaluate the performance of municipal institutions contribute to measuring the efficiency and effectiveness of services provided has reac
... Show More