Recently, some of Iraq's newly constructed asphalt concrete pavements showed premature failures with significant negative impacts on roadway safety and the economy. Using Nano hydrated lime (NHL) in pavement construction could be one of the possible steps to improve pavement durability. This article discusses how NHL affects the durability of hot mix asphalt. NHL was added in two methods to the asphalt concrete mixture for the wearing course. The first is the dry method, i.e., on the aggregate, whereas the second is the wet addition method, i.e., to the bitumen. The percentages were tried for each additional method; 1, 2, and 3% by weight of aggregate for the dry method and 0.5, 1, and 1.5% by weight of asphalt concrete for the wet method. The optimum asphalt cement contents were evaluated using the Marshall procedure. Asphalt concrete mixes were prepared at their optimum asphalt content and then tested to evaluate their durability properties, including moisture damage and permanent deformation. These properties have been evaluated using indirect tensile strength and uniaxial repeated loading tests. The results show that the NHL has improved the permanent deformation characteristics and resistance to moisture susceptibility.
Recycled asphalt concrete mixture are prepared, artificially aged and processed in the laboratory to maintain the homogeneity of recycled asphalt concrete mixture gradation, and bitumen content. The loose asphalt concrete mix was subjected to cycle of accelerated aging, (short –term aging) and the compacted mix was subjected to (long -term aging) as per Super-pave procedure. Twenty four Specimens were constructed at optimum asphalt content according to Marshall Method. Recycled mixture was prepared from aged asphalt concrete using recycling agent (soft asphalt cement blended with silica fumes) by (1.5%) weight of mixture as recycling agent content. The effect of recycling agent on aging after recycling process behavior
... Show MoreIn this paper, mesoscale modeling is performed to simulate and understand fracture behavior of two concrete composites: cement and asphalt concrete using disk-shaped compact tension (DCT) tests. Mesoscale models are used as alternative to macroscale models to obtain better realistic behavior of composite and heterogeneous materials such as cement and asphalt concrete. In mesoscale models, aggregate and matrix are represented as distinct materials and each material has its characteristic properties. Disk-shaped compact tension test is used to obtain tensile strength and fracture energy of materials. This test can be used as a better alternative to other tests such as three points bending tests because it is more convenient for both field and
... Show MoreThe High Modulus Asphalt Concrete Mixture (HMACM) or (EME) (Enrobes a Module Eleve) developed in France, since, 1980 by Laboratories Central des Ponts et Chaussees (LCPC). Due to the increasing in traffic intensity and axle loading this type of mixing were suitable for pavement subjected to heavy duty. Experiments showed that EME mixtures have an excellent moisture damage resistance permanent deformation, fatigue cracking and reducing costs of maintenance and a significant reduction in thickness of pavement. Because of the high stiffness of EME mixes, the stresses transformed to the bottom laid layer by repeated traffic wheel loads were reduced effectively. This study intend to focus the light into the possibility of producing asphalt mixtu
... Show MoreThe study aims at finding out the effect of the lead time strategy on the first intermediate class pupils' achievement in geography The partial experimental design of two groups, experimental and control, with pre-post tests is used. The sample is represented in (73) female pupils. The sample is divided into two groups (37) experimental group and (36) control one. The sam ple is selected from first intermediate class pupils ( Al Batol intermediate school for girls) Baghdad Al-karkh-3, for academic year 2015-2016 The researcher has equalized the two groups in several variables: the previous achievement tests, intelligence, age in months, the scores of geography test of first course
In this study, phytoplankton density, chlorophyll-a, and selected physico- chemical parameters were investigated in Erbil wastewater channel. The surveys were carried out monthly from May 2003 to April 2004. Samplings were established on three sites from headwaters to the mouth. The results showed that pH was in alkaline side of neutrality, with significant differences (P<0.05) between sites 1 and 3. TSS concentration decreased from site 1 toward site 2 (mean value, 80.15 to 25.79 mg.l-1). A clear gradual increase in mineral content (TDS) observed from site one of the channel towards the mouthpart. Soluble reactive phosphate has a concentration maximum mean value reached 48.4 µg.l-1 which is recorded in site 2. A high positive relat
... Show MoreThe loose sand is subject to large settlement when it is exposed to high stresses. This settlement is due to the nature of the high drainage of sand, which displays foundations and constructions to a large danger. The densification of loose sandy soils is required to provide sufficient bearing capacity for the structures. Thus soil stabilization is used to avoid failure in the facilities. Traditional methods of stabilized sandy soil such as fly ash, bituminous, and cement often require an extended curing period. The use of polymers to stabilize sandy soils is more extensive nowadays because it does not require a long curing time in addition to being chemically stable. In this study, the effect of adding different percent
... Show MoreDespite the significant increase in public spending in Iraq, it was not directed toward the important sectors that have an important role in correcting the productive structure. Rather, most of the public expenditure was going to cover the required imports, or to face shocks, whether security or health, and this caused a continuous decrease in the volume of Iraq's exports of goods and services, as the aim of the study was to review the importance of public debt and its impact on the trade balance, as well as to know the economic policies that can contribute to strengthening the trade balance, as the study proved through the (ARDL) model that there is a direct relationship between the domestic debt and the net trade balance, and an invers
... Show MoreThe current research aims to test the effect of knowledge sharing in its dimensions represented by(individual dimension, organizational dimension, and technological dimension), In reducing the strategic Anxiety of Iraqi Airways, In view of the importance of the two variables for the company from the perspective of society and the sample resulting from directing various organizational phenomena to reduce its strategic Anxiety, As a goal, it should be viewed from multifaceted perspectives(uncertainty, relational disorder, competitive disorder, resource depletion), And it was embodied by choosing the descriptive, exploratory approach, as it is the most appropriate in that aspect, so that the research questionnaire is one of solid scientific
... Show MoreTechnical education in Iraq Composed of, a complex system of technical competence and scientific, technical and administrative, which extends to cover large areas of the country and constitute a vicious circle between economic development, social and cultural rights through middle-management on the one hand, and between academic knowledge and political decision-making, which aims to bring such development On the other hand, in the light of that education is the actual technical extension applied to create the idea of complementarily between them. In Iraq, have been distributed institutes and technical colleges to achieve those goals, in addition to realizing the idea of integration between them and community, and integration of t
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