Undoubtedly, rutting in asphalt concrete pavement is considered a major dilemma in terms of pavement performance and safety faced by road users as well as the road authorities. Rutting is a bowl-shaped depression in the wheel paths that develop gradually with the increasing number of load applications. Heavy axle loadings besides the high pavement summer temperature enhance the problem of rutting. According to the AASHTO design equation for flexible pavements, a 1.1 in rut depth will reduce the present serviceability index of relatively new pavement, having no other distress, from 4.2 to 2.5. With this amount of drop in serviceability, the entire life of the pavement in effect has been lost. Therefore, it is crucial to look at the mechanism, possible reasons, as well as techniques, to reduce the rutting in order to offer long service life and safe roadways. To this end, the need has been arising for this research which deals mainly with a thorough review of the existing literature to highlight some key points for the researchers and pavement engineers related to rutting mechanism, measurement, and criteria, both intrinsic (mixture variables) and extrinsic (traffic and temperature) contributory factors to rutting, material characterization, test methods, and prediction methodologies, as well as possible ways to minimize the rutting distress in asphalt concrete pavement. So far, this research attempts to bridge the gap in the literature that frequently only addresses a single aspect of rutting by providing an in-depth review of rutting in asphalt concrete and thereby offers a complete comprehensive understanding of this major distress type.
The main factors that make it possible to get the corrosion of reinforcing steel in concrete are chloride ions and the absorption of carbon dioxide from the environment, and each of them works with a mechanism which destroys the stable immunity of rebar in the concrete. In this work the effect of carbon dioxide content in the artificial concrete solution on the corrosion behavior of carbon steel reinforcing bar (CSRB) was studied, potentiostatically using CO2 stream gas at 6 level of concentrations; 0.03 to 2.0 weight percent, and the effect of rising electrolyte temperature was also followed in the range 20 to 50ᴼ C. Tafel plots and cyclic polarization procedures were obeyed to investigate the c
... Show MoreThis paper aims to give an overview of acculturation in the literature by means of its explicit definitions, main characteristics, and categorical process. It also foreshadows the significance of acquiring novice culture with particular connection to second language acquisition. Schumann and John Berry underscored acculturation each with its own model of acculturation. In the case of this review, you will realize that Schumann's two main aspects are firmly rooted in berry's model of acculturation as an exclusive description in relation to second language acquisition. Steven Krashen outlined acquiring language from the intellectual and linguistic view of learning, whereas Micheal Long demanded for communication in social perspective. It has
... Show MoreHS Saeed, SS Abdul-Jabbar, SG Mohammed, EA Abed, HS Ibrahem, Solid State Technology, 2020
Language mirrors understanding of the same or other culture. Meaning is hardly encoded in the world community. Some linguists cannot solve language problems because of its abstractedness. Language communicators learn the second or foreign language at schools for three reasons. First, English is not their first language. Second, they have little or no educational background in experiencing what they know in another language. Third, they have not improved their communication skills in English. Analyzing the language as a mean of communication would not be learned enough without its practice. This paper gives an exclusive preview of applied linguistics. It defines the conversion of different areas of the study of language with second o
... Show MoreLow back pain a major causes of morbidity throughout the world and it is a most debilitating condition ,and can lead to decreased physical function ,compromised quality of life, and psychological distress. Obesity is nowadays a pandemic condition. Obese subjects are commonly characterized by musculoskeletal disorders and particularly by non-specific LBP. However, the relationship between obesity and LBP remain to date unsupported by objective measurements of mechanical behavior of spine and it is morphology in obese subjects. Key words: obesity, low back pain,
Preserving and saving energy have never been more important, thus the requirement for more effective and efficient heat exchangers has never been more important. However, in order to pave the way for the proposal of a truly efficient technique, there is a need to understand the shortcomings and strengths of various aspects of heat transfer techniques. This review aims to systematically identify these characteristics two of the most popular passive heat transfer techniques: nanofluids and helically coiled tubes. The review indicated that nanoparticles improve thermal conductivity of base fluid and that the nanoparticle size, as well as the concentrations of the nanoparticles plays a major role in the effectiveness of the nanofluids.
... Show MoreLow back pain a major causes of morbidity throughout the world and it is a most debilitating condition ,and can lead to decreased physical function ,compromised quality of life, and psychological distress.
Obesity is nowadays a pandemic condition. Obese subjects are commonly characterized by musculoskeletal disorders and particularly by non-specific LBP. However, the relationship between obesity and LBP remain to date unsupported by objective measurements of mechanical behavior of spine and it is morphology in obese subjects. &nb
... Show MoreAmygdalin (d-Mandelonitrile 6-O-β-d-glucosido-β-d-glucoside) and its semi synthetic product is Laetrile ( also called vitamin B17): a natural cyanogenic glycoside occurring in the seeds of some edible plants, such as bitter almonds and peaches. Early in the 19th century, Amygdalin was first isolated in 1830 by two French chemists, Robiquet and Boutron-Charlard, as active components in various fruit pits and raw nuts. However, the systematized study of vitamin B17 started when chemist Bohn (1802) discovered that a hydrocyanic acid is released during distillation of the water from bitter almonds. The various pharmacological effects of Laetrile include antiatherogenic, activity in renal fibrosis, pulmonary fibrosis, immune regulation, ant
... Show MoreDuring the last two decades, nanomaterial application has gained a significant attraction into asphalt technology due to their effect in enhancing asphalt binder improving the asphaltic mixture. This study will modify the asphalt binder with two different nano types, nano SiO2 and CaCO3, at levels ranging from 1% to 7%. The resulting optimum nano-modified Asphalt will be subject to a series of rheological tests, including dynamic shear rheometer (DSR), Viscosity, and bending beam rheometer (BBR) to determine asphalt binder sensitivity towards low-medium-high temperature range. Results indicate that both nano types improved the physical characteristics of Asphalt, and 5% by weight of Asphalt was suggested as a reasonable dosage of nano-SiO2
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