Hydrated lime has been recognized as an effective additive used to improve asphalt concrete properties in pavement applications. However, further work is still needed to quantify the effect of hydrated lime on asphaltic concrete performance under varied weather, temperature, and environmental conditions and in the application of different pavement courses. A research project was conducted using hydrated lime to modify the asphalt concretes used for the applications of wearing (surface), leveling (binder), and base courses. A previous publication reported the experimental study on the resistance to Marshall stability and the volumetric properties, the resilient modulus, and permanent deformation at three different weather temperatures. This paper reports the second phase of the experimental study for material durability, which investigated the effect of hydrated lime content on moisture susceptibility when exposed to a freeze-thaw cycle, and fatigue life. The experimental results showed an improvement in the durability of the modified asphalt concrete mixtures. Optimum hydrated lime contents for different course applications are suggested based on the series experimental studies. Finally, the advantage of using the optimum mixtures for a pavement application is demonstrated.
This research is devoted to study the strengthening technique for the existing reinforced concrete beams using external post-tensioning. An analytical methodology is proposed to predict the value of the effective prestress force for the external tendons required to close cracks in existing beams. The external prestressing force required to close cracks in existing members is only a part from the total strengthening force.
A computer program created by Oukaili (1997) and developed by Alhawwassi (2008) to evaluate curvature and deflection for reinforced concrete beams or internally prestressed concrete beams is modified to evaluate the deflection and the stress of the external tendons for the externally strengthened beams using Matlab
The aim of this research work is to study the effect of stabilizing gypseous soil, which covers vast areas in the middle, west and south parts of Iraq, using liquid asphalt on its strength properties to be used as a base course layer replacing the traditional materials of coarse aggregate and broken stones which are scarce at economical prices and hauling distances. Gypseous soil brought from Al-Ramadi City, west of Iraq, with gypsum content of 66.65%, medium curing cutback asphalt (MC-30), and hydrated lime are used in this study. The conducted tests on untreated and treated gypseous soil with different percentages of medium curing cutback asphalt (MC-30), water, and lime were: unconfined compression strength, and one dimensional confine
... Show MoreGypseous soil is considered as a problematic soil for embankment construction, however, implementation of emulsified asphalt as a stabilization agent could be a proper solution for enhancing its properties as a subgrade soil. In this work, the sustainability of asphalt stabilized soil has been assessed in terms of its resistance to cyclic (freezing-thawing) and (heating-cooling) processes. Specimens have been prepared at optimum fluid content (moisture and emulsion) and tested under direct shear stresses while subjected to 30 cycles of (freezing-thawing) and (heating-cooling). Both of dry and soaked testing conditions have been implemented. Data have been observed after each 10 cycles, and compared with that of reference mix. It was conclud
... Show MoreOne of the most severe problems with flexible asphalt pavements is permanent deformation in the form of rutting. Accordingly, the practice of adding fiber elements to asphalt mix to improve performance under dynamic loading has grown significantly in order to prevent rutting distress and ensure a safe and long-lasting road surface. This paper explores the effects of a combination of ceramic fiber (CF), a low-cost, easily available mineral fiber, and thermal insulator fiber reinforced to enhance the Marshall properties and increase the rutting resistance of asphalt mixes at high temperatures. Asphalt mixtures with 0%, 0.75%, 1.5%, and 2.25% CF content were prepared, and Marshall stability and wheel tracking tests were employed to stu
... Show MoreAbstract
Business organizations are using the technological innovations like cloud computing (CC) as a developmental platform in order to improve the performance of their information systems. In that context, our paper discusses know-how in employing the public and private CC to serve as platforms to develop the evaluation system of annual employees' performance (ESAEP) at Iraqi universities. Therefore, we ask the paper question which is “Is it possible to adopt the innovative solutions of ICTs (Like: public and private CC) for finding the developmental vision about management information systems at business organizations?”. In addition, the paper aim
... Show MoreObjective: The descriptive study was used to evaluate nursing staff performance in cardiac care units at teaching
and non teaching hospitals in kirkuk city: A comparative study.
Methodology: A descriptive study was used to evaluate nursing staff performance in cardiac care units. The study
was conducted from December 29th
, 2013 up to the 27th of Apr. 2014. A non-probability (purposive) sample of
(44) nurses who work in cardiac care unit at Azady teaching Hospital and Kirkuk general Hospital was evaluated by
a questionnaire which consisted of two parts; the first part is concerned with the demographic characteristics of
the nurses and the second part concerned Observation check list for evaluation nursing staff Perfo
Bacteriocins were partially purified by ammonium sulphate 50% concentraction, bacteriocin activity of Pediococcus acidilactici-FMAC278 was 25600 U/ml with 5.8 folds and 7.6% yeild, the activity decrease to 12800 U/ml after dialysis with 6.3 folds and 3% yield, On the other hand the bacteriocin activity of Weissella paramesenteroides-DFR6 was 12800 U/ml with 2.7 folds and 8.8% yeild, after dialysis the activity became 6400 U/ml with 5.1 fold and 3.4% yield, Chicken Sausage were made by adding 0.25, 0.5 and 1% particaly purified bacteriocin to study its effect on microorganisms and increasing shelf life of Sausage. It is found that bacterial numbers were decreased after 3 days of storage at refrigerator at 0.5% conc. While the molds decrea
... Show MoreThe icon and the symbol represent the constituents of the communication process, through their intellectual and philosophical concepts that have been addressed by the current research that it has touched upon their importance in conveying the design idea for the recipient and showing the specificity of each one of them in the communication process. The research problem has been limited by the following question: what are the communication roles that the symbol and the icon present for the user in designing the industrial product?
The research objective is to reveal the theoretical visualization that describes the icon and the symbol in the industrial product and its importance in the communication process through stating the of simil