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.
Abstract The study aims to clarify the value of auditing economic units and how it can be measured, which is one of the most important challenges to matching the Value Relevance of Accounting Information. The problem of the study was identified with questions that revolve around the extent to which it is possible to measure the value of auditing in Iraqi economic units and the extent to which the value of auditing affects the adequacy of accounting information. Through reviewing the studies discussing this topic, it was found that auditing can provide value through the performance of the auditor and adding value to the economic unit subject to audit. The study recommended the need to study the situational factors of auditing, whether exter
... Show MoreThe transition states that Iraq economy lived it after 2003, and the change in tools used by monetary policy based on C.B.I law 56 in 2004, under the especially situation for the economy (structural imbalances and the weakness of banking & financial sector).
The monetary policy adopted the inflation targeting policy to mantain the monetary stability in the economy and considered it an incubator for future growth. It used the exchange rate as a nominal anchor to achieve the goal (because the rentier of economy, finance Shallowness & separation between real sector and finance sector, all this cause the normal channel to transfer the effect of monetary policy (interest rate) ineffective.
... Show MoreThis study numerically intends to evaluate the effects of arc-shaped fins on the melting capability of a triplex-tube confinement system filled with phase-change materials (PCMs). In contrast to situations with no fins, where PCM exhibits relatively poor heat response, in this study, the thermal performance is modified using novel arc-shaped fins with various circular angles and orientations compared with traditional rectangular fins. Several inline and staggered layouts are also assessed to maximize the fin’s efficacy. The effect of the nearby natural convection is further investigated by adding a fin to the bottom of the heat-storage domain. Additionally, the Reynolds number and temperature of the heat-transfer fluid (HTF) are e
... Show MoreThe research aims at identifying the importance of scientific research for researchers and in creating new knowledge، development and utilization of mental and cognitive energies and developed them with the ability to research، extrapolation، meditation and then conclusion. The information was collected by interviewing the Secretary-General of the Central Library and by distributing questionnaire forms to the (33) teaching staff of the College of Higher Education. The responses of the society were analyzed the result and the recommendations were the most important 1. Information specialist and all employees of the administrators and technicians in the centers of information sources (libraries) and in the field are considered scientific r
... Show MoreThe research aims to study the basic concepts of the underwriting policy with its various indicators. The researcher studies the underwriting policy with its various indicators (sex, health status, age of the insured, insurance amount, The method of acceptance, payment method, and duration of insurance) where each of these indicators constitute an important factor in the productivity of life insurance policies, where the productivity of life insurance policies face many difficulties because insurance is a service and not a tangible material commodity and its benefits and not current. Therefore, the life insurance company needs to use a prudent underwriting policy so as not to endanger its financial position due to the expansion of the un
... Show MoreA thin film of SnSe were deposited by thermal evaporation technique on 400 ±20 nm thick glass substrates of these films were annealed at different temperatures (100,150,200 ⁰C), The effect of annealing on the characteristics of the nano crystalline SnSe thin films was investigated using XRD, UV-VIS absorption spectroscopy, Atomic Force Microscope (AFM), and Hall effect measurements. The results of X-ray displayed that all the thin films have polycrystalline and orthorhombic structure in nature, while UV-VIS study showed that the SnSe has direct band gap of nano crystalline and it is changed from 60.12 to 94.70 nm with increasing annealing temperature. Hall effect measurements showed that all the films have a positive Hall coeffic
... Show MoreThe design of components subjected to contact stress as local compressive stress is important in engineering application especially in ball and socket Joining. Two kinds of contact stress are introduced in the ball and socket joint, the first is from normal contact while the other is from sliding contact. Although joining two long links (drive shaft in steering cars) will cause the effect of flexural and tensional buckling stress in hollow columns through the ball and socket ends on the failure condition of the joining mechanism. In this paper the consideration of the combined effect of buckling Load and contact stress on the ball and socket joints have been taken, epically on the stress distribution in the contact area. Different
... Show More