The performance of asphalt concrete pavement has affected by many factors, the temperature is the most important environmental one which has a large effect on the structural behavior of flexible pavement materials. The main cause of premature failure of pavement is the rutting, Due to the viscoelastic nature of the asphalt cement, rutting is more pronounced in hot climate areas because the viscosity of the asphalt binder which is
inversely related to rutting is significantly reduced with the increase in temperature resulting in a more rut susceptible paving mixtures. The objective of this study is to determine the effect of temperatures variations on the permanent deformation parameters (permanent strain (p), intercept (a), slope (b), Alpha and Mu) as well as resilient strain (r) and resilient modulus (Mr). To achieve this objective, one aggregate gradation with 12.5mm nominal maximum size, two grades of asphalt cements (40-50 and 60-70) brought form Al- Daurah refinery, limestone dust filler has been used to prepare the asphalt concrete mixtures. 30 Marshall specimens were prepared to determine the optimum asphalt cement content. Thereafter, 30 cylindrical asphalt concrete specimens (102mm in diameter and 203 mm in height) are prepared in optimum asphalt cement and optimum ±0.5 percent. The prepared specimens were used in uniaxial repeated load test to evaluate the permanent deformation parameters of asphalt concrete mixes under the following testing temperature (5, 15, 25, 40 and 60c). The test result analyses appeared that Mr is decrease 51 percent when temperature increased from 5 c to 25 c and then decrease 22 percent with further increase in temperature from 25 c to 60 c. Also, the Alpha value decreases by a factor of 1.25 and 1.13 when temperature increases from 5 c to 25 c and 25 c to 60 c, espectively.
Finally, statistical models were developed to predict the Alpha and Mu parameters of permanent deformation.
The main objective of this research is to find out the effect of deviation in the aggregate gradients of asphalt mixtures from the Job Mix Formula (JMF) on the general mixture performance. Three road layers were worked on (wearing layer, binder layer, and base layer) and statistical analysis was performed for the data of completed projects in Baghdad city, and the sieve that carried the largest number of deviations for each layer was identified. No.8 sieve (2.36mm), No.50 sieve (0.3mm), and 3/8'' sieve (9.5mm) had the largest number of deviations in the wearing layer, the binder layer, and the base layer respectively. After that, a mixture called Mix 1, was made. This mixture was selected from a number of completed mixtures, and it
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Affinity is a term used to describe the amount of the adhesion bond between asphalt binder and aggregate. Adhesion force may be used as indicator to the amount of energy or work required to breakdown the adhesive bond between asphalt binder and aggregate. In order to study affinity between asphalt binder and aggregate, a modified device is manufacture locally similar to Rolling Bottle Test (RBT) to Predicted the degree of affinity between asphalt binder and aggregate; taking into consideration mineral composition with physical properties of asphalt binder to measure required force to separate asphalt binder from aggregate surface. In this study, suggest new parameters to represent the stripping or affinity phenomena (aff
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Warm Mix Asphalt (WMA) is a modern energy-saving process that uses environmentally friendly materials, has lower mixing and compaction temperatures, and uses less energy and releases less contaminants than conventional hot mix asphalt. Moisture damage poses one of the main challenges of the material design in asphalt pavements. During its design life, the asphalt pavement is exposed to the effect of moisture from the surrounding environment. This research intends to investigate the role of the polypropylene fibres for modifying the moisture susceptibility for the WMA by using different percentages of polypropylene (namely 2, 4, and 6%) by weight of the binder of the control mixture (WMA). In this paper, the physical characteristics
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One of the major problems facing the road construction engineer is the collapsible granular soil which may be used for embankment construction. Problems appears when such compacted soil come in touch with water, it exhibits cracking and uncontrolled settlement. Collapsible soils are defined as any unsaturated soil that goes through a radical rearrangement of practice and great loss of volume upon wetting, with or without additional loading. An attempt has been made in this investigation to stabilize the collapsible soil of Nasiriya with asphalt emulsion. Specimens of pure and asphalt emulsion stabilized soil have been prepared using optimum fluid content and tested. The first group of specimens of (60x60x20) cm have been tested for direct s
... Show MoreFor over a century, the global consumption of asphalt binder in asphalt mixture production has been substantial. In the Heet region (west of Iraq), two distinct forms of natural asphalt (NA) deposits exist: rock asphalt and sulfur spring asphalt. This study focused on using NA sourced from sulfur springs. The aim was to investigate the potential of incorporating NA into local asphalt mixtures. To achieve this, NA was heated to 163°C for varying durations. After heat treatment, laboratory tests were conducted on NA. The findings suggest that by heating NA for 20 hours, it conforms to Iraqi specifications in terms of physical properties. Furthermore, compared to conventional petroleum asphalt, treated NA showed greater
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Objective: To determine the impact of personal hygiene on woman who complain pelvic inflammatory disease Methodology: A quasi experimental study in the High Institute Infertility Diagnostic and A.R.T.(assistance reproductive technology) in AL-Kadimya city and al-Emamian al Kadmain medical city hospital. The sample collected during (26th ) January – (30th ) April 2014. A purposive sample of (60) women, (30) of them regard as study group and (30) regard as a control group whom they take routine care in the institute and hospital. The questionnaire consisted of socio-demographic data, reproductive heal
AbstractObjectives: The work environment has an impact on the performance of nurses, as well as to determine the relationship between the work environment and the performance of nurses.Research methodology: A descriptive analytical study was designed for the impact of the work environment on the performance of nurses' jobs in the hospitals of the city of Nasiriyah. The study began in the period from May 15, 2022 to 1 November, 2022. The non-probability (purposive) sample consisted of (410) nurses working in the city center hospitals. Nasiriyah, they were chosen based on the study criteria, and after obtaining approval from them. The data was collected using the questionnaire, which consi
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In the present paper, the researcher attempts to shed some light on the objective behind inserting some Qur'anic verses by Al-Zahraa (Peace Be Upon Her) in her revered speech. Besides, it tries to investigate the hidden meaning of these verses and to study them in the light of pragmaticreferences. This task is supported by Books of Tafseer as well as the books that explained this speech to arrive at its intended meaning. It is possible say that this is astep towards studying speeches of 'Ahlul Bayt' (People of the Prophet's household) in terms of modern linguistic studies, as well as employing modern methods to explore the aesthetic values of these texts.
Objective: To find out if there are any significant differences between these women's knowledge in the
management of Breast Self-Examination in study and control group regarding some variables.
Methodology: A quasi-experimental design was used. A purposive "non-probability" sample of (260) women who
are employee and students in both colleges (Nursing and Health and Medical Technologies) was selected. The
sample consists of two groups, experimental group (130) includes those in (Nursing college), and control group
(130) in (Health and Medical Technologies). A questionnaire was constructed which included demographic
information, reproductive information, family history, previous medical history, and information about wome