Reflection cracking in asphalt concrete (AC) overlays is a common form of pavement deterioration that occurs when underlying cracks and joints in the pavement structure propagate through an overlay due to thermal and traffic-induced movement, ultimately degrading the pavement’s lifespan and performance. This study aims to determine how alterations in overlay thickness and temperature conditions, the incorporation of chopped fibers, and the use of geotextiles influence the overlay’s capacity to postpone the occurrence of reflection cracking. To achieve the above objective, a total of 36 prism specimens were prepared and tested using an overlay testing machine (OTM). The variables considered in this study were the thickness of the overlay (40, 50, and 60 mm), temperature (20, 30, and 40 °C), mix type (reference mix and mix modified with 10% chopped fibers by weight of asphalt cement), and the inclusion of geotextile fabric at two positions (one-third of the depth from the base and at the bottom). The research outcomes revealed that a decreased temperature and thicker overlay led to a higher resistance to crack initiation and full propagation, as indicated by the values of critical fracture energy (Gc) and crack progression rate (CPR). Furthermore, the study observed the enhanced crack resistance of overlays in the presence of geotextiles, whether at the bottom or one-third of the depth from the bottom, with superior performance of the former. Despite a slight enhancement in certain properties, the incorporation of chopped fibers in the overlays did not substantially improve the overall performance compared to the reference specimens. Overall, the study provides valuable insights into the variables that influence the ability of AC overlays to mitigate reflection cracking. These findings will aid engineers and designers in making informed decisions regarding overlay design and construction.
The nuclear matter density distributions, elastic electron scattering charge form
factors and root-mean square (rms) proton, charge, neutron and matter radii are
studied for neutron-rich 6,8He and 19C nuclei and proton-rich 8B and 17Ne nuclei. The
local scale transformation (LST) are used to improve the performance radial wave
function of harmonic-oscillator wave function in order to generate the long tail
behavior appeared in matter density distribution at high . A good agreement results
are obtained for aforementioned quantities in the used model.
The issue of peaceful coexistence between societies is the topic of the hour, as it is one of the important issues in this era, especially in days when conflicts and conflicts abound, and even wars in the name of religion, gender, race, language, and the like. The world, so that single-mindedness and adherence to one opinion and intolerance to it became the method of dialogue in our world today, as writing in the field of peaceful coexistence, peace-building, tolerance, pluralism, and acceptance of the other is one of the new fields of knowledge in Iraq in general and in Nineveh Governorate in particular, as peaceful coexistence is one of the basic needs And necessary for the presence of individuals in societies, and it requires the achi
... Show MoreThis paper represents an experimentalattempt to predict the influence of CO2-MAG welding variables on the shape factors of the weld joint geometry. Theinput variables were welding arc voltage, wire feeding speed and gas flow rate to investigate their effects on the shape factorsof the weld joint geometry in terms of weld joint dimensions (bead width, reinforcement height, and penetration). Design of experiment with response surface methodology technique was employed to buildmathematical models for shape factors in terms of the input welding variables. Thepredicted models were found quadratic type and statistically checked by ANOVA analysis for adequacy purpose. Also, numerical and graphical optimizations were carried out
... Show MoreLean Six Sigma methodologies and Ergonomics principles are the main pillars of this work given their importance in the implementation of continuous improvement in assembly workstations design. When looking at the introduction of the Ergonomics that has been affected by the integration of the Lean and Six Sigma for improvements, it is necessary to understand why these methodologies belong to each other and how they can be handled in the industrial field. The aim of the work seeks towards the impact of analyzing the integration of the basics tools of Lean and Six Sigma that enhanced Ergonomics highlighted the importance of using the priority matrix in the selection of the priority criteria. Two models of a system based on
... Show MoreThis work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to cont
... Show MoreBackground: Dental erosion is a common oral condition which results due to consumption of high caloric and low pH acidic food such as carbonated drinks and fruit juices. It is expected that these food types can cause irreversible damage to dental hard tissues and early deterioration of the dental restorations. So, this study aimed to evaluate and compare the erosive potential effects of orange fruit juice and Miranda orange drink on the microhardness of an orthodontic composite material. Materials and methods: Thirty discs with a thickness of 2 mm and a diameter of 10 mm were prepared from orthodontic bonding composite. The prepared discs were equally divided into three groups (n=10). Microhardness analysis was carried out both prior to
... Show MoreNew polymers were prepared from a monomer (5-vinyl-1H-tetrazole), which was prepared from acrylonitrile with sodium azide in the presence of ZnCl2.Another monomer (Methyl acrylate) was also used. Co-monomers were polymerized usingBPO as initiator. The second step was the preparation of copoly acid hydrazide from the reaction of compound2 with hydrazine hydrate, followed by the reaction with carbon disulphide in the presence of KOH to obtain copoly (5-subs.-2-mercapto-1,3,4-thiadiazole). Next,compound4 was reacted with chloroacetyl chloride to yield compound4 5 which was reacted with (hydrazine hydrate , phenyl hydrazine and 2,4-di nitro phenyl hydrazine) as shown in scheme(1). Physical properties of all the prepared copolymers were chara
... Show MoreBackground Cadmium (Cd), one of the most abundant heavy metals, is extremely toxic to both humans and animals. hIt is well known that zinc (Zn) administration reduces Cd-induced toxicity and that metallothioneins can have a protective effect in biological systems to mitigate Cd toxicity. Objective The aim of the current study to determine if Zn administration affected the induction of MT-1 and MT-2 in the liver tissue in mice exposed to Cd. Materials and methods Metallothionein protein (MT) level in the tissue of male mice were detected using the anion -exchang high-performance liquid chromatography coupled (HPLC)assay and immunohistochemical staining. Results Single treatment to zinc or cadmium increase the level of MT in the liver, but zi
... Show MoreHypertension is one of the leading causes of the global burden of disease, which causes serious health problems. The aim of this study is to investigate the lipid profile levels in sera of Iraqi hypertensive patients by measuring Total cholesterol (TC), triglyceride (TG) and low density lipoproteins (LDL) and kidney function levels by measuring uric acid, urea and creatinine. Seventy five individuals of Iraqi adults (Males) were divided into three groups: 25 hypertensive patients with duration of disease (1-10) year (group 1), 25 hypertensive patients with duration of disease (11-30) year (group 2) and 25 normal individuals as control group (group3). The findings indicate that serum (TC, TG and LDL) levels were significantly elevated (
... Show MoreSince the inflammatory factor IL-6 known by its critical role in different metabolic reactions in the
body, therefore, this study was designed to detect it is effect in the thyroid gland function by
injecting three groups of rats, the first with IL-6 , the second with carbimazole (antithyroid drug) and
the third with normal saline (Control).The experiment included three groups of rat; each was injected
with recombinant human interleukin-6 (rhIL-6), Carbimazole, or normal saline (Control). The results
of experiments showed that both IL-6 and carbimazole caused a decrease in the levels of thyroid
hormones (T3 and T4) in animal sera, and a significant decrease in animal body weight, but had no
effect on the liver weight