Concrete pavements are essential to modern infrastructure, but their low tensile and flexural strengths can cause cracking and shrinkage. This study evaluates fiber reinforcement with steel and carbon fibers in various combinations to improve rigid pavement performance. Six concrete mixes were tested: a control mix with no fiber, a mix with 1% steel fiber (SF1%), a mix with 1% carbon fiber (CF1%), and three hybrid mixes with 1% fiber content: 0.75% steel /0.25% carbon fiber (SF0.75CF0.25), 0.25% steel /0.75% carbon fiber (SF0.25CF0.75), and 0.5% steel /0.5% carbon fiber ((SF0.5CF0.5). Laboratory experiments including compressive, flexural, and splitting tensile strength tests were conducted at 7, 28, and 90 days, while Finite Element Analysis (FEA) using ABAQUS software was developed to examine pavement behavior under repeated loading. The results revealed that at 90 days, the SF1% mix exhibited a 9.1% improved compressive strength and CF1% mix a 7.3% improved strength over the control mix. The SF1% mix increased flexural strength by 72.5% and the CF1% mix by 48.6%. Additionally, splitting tensile strength increased by 70% for the SF1% and 45.5% for the CF1%. The hybrid mixes improved compressive strength by 7.6%-8.5%, flexural strength by 59.7%-70.2%, and splitting tensile strength by 56%-67.8%. The finite element modeling showed that the control mix was displaced 15 mm under repeated loading, while the SF1% reduced displacement by 35% and the hybrid mixes by 30%. These findings indicated that SF1% exhibited the best mechanical properties. However, fiber reinforcement, whether used single or in hybrid combinations, improves concrete pavement mechanical performance and loading behavior, offering a promising way to infrastructure durability and service life.
The performance analyses of 15 kWp (kW peak) Grid -Tied solar PV system (that considered first of its type) implemented at the Training and Energy Research Center Subsidiary of Iraqi Ministry of Electricity in Baghdad city has been achieved. The system consists of 72 modules arranged in 6 strings were each string contains 12 modules connected in series to increase the voltage output while these strings connected in parallel to increase the current output. According to the observed duration, the reference daily yields, array daily yields and final daily yields of this system were (5.9, 4.56, 4.4) kWh/kWp/day respectively. The energy yield was 1585 kWh/kWp/year while the annual total solar irradiation received by solar array system was 198
... Show MoreModal verbs are also called auxiliary verbs, helping verbs and modal auxiliaries. They are special auxiliary verbs that express the degree /of certainty of the action in the sentence, attitude or opinion of the writer concerning the action. These auxiliary verbs are can, could ,may, might, must, ought to, shall, should, will, would and had better. Modality is one of the most difficult aspects of learning English, because the form of modals does not follow the conventional rules of grammar, and there are so many meanings of modals that students often get confused about which modal to use. Also, many EFL learners face difficulty in choosing the proper modal verb that fit certain situations because each modal verb has many functions. The pr
... Show MoreVarious theories on learning have been developed with increasing frequency in the last
few decades. In tandem with this, Multiple Intelligence theory appeared as a new approach to
education as well as an important theory in the field of language learning. Gardner explains
that all human beings have different intelligence fields and a potential to develop them. These
intelligences are (verbal-linguistic, logical-mathematical, visual-spatial, musical, bodilykinesthetic,
interpersonal, intrapersonal, naturalistic, and Existential).
This study aims at investigating Multiple Intelligences of Iraqi college EFL students. To
achieve the aims of the study, a questionnaire is adopted according to Birmingham model
which incl
The research aimed to identify and build two specialized scales for cognitive load and mental stress and to identify the level of each of them among 110-meter steeplechase runners among youth, and to prepare a psychological counseling approach to reduce the level of cognitive load and mental stress among 110-meter steeplechase runners among youth, so that the two research hypotheses are that there are differences. There are statistically significant differences between the results of the pre- and post-tests of the experimental group in measuring cognitive load. There are statistically significant differences between the results of the pre- and post-tests of the experimental group in measuring mental stress. The experimental method w
... Show Moreconversation is an oral skill in which two persons can exchange their ideas, thoughts and opinions to communicate with each other. Learners can work in pairs or groups to practice dialogues chosen by the teacher from their textbook materials or from additional resources. Nowadays, because of Corona virus infection, our college students are taught all the subjects including conversation course either via google classroom platform or any other platforms. Google meet is one of online meetings between the teacher and students, i.e., a video meet in which students and the teacher join the online meetings in a specified time to communicate, express their ideas, thoughts and feelings about what is mentioned above. In this study, the resea
... Show MoreThis research aims to investigate the color distribution of a huge sample of 613654 galaxies from the Sloan Digital Sky Survey (SDSS). Those galaxies are at a redshift of 0.001 - 0.5 and have magnitudes of g = 17 - 20. Five subsamples of galaxies at redshifts of (0.001 - 0.1), (0.1 - 0.2), (0.2 - 0.3), (0.3 - 0.4) and (0.4 - 0.5) have been extracted from the main sample. The color distributions (u-g), (g-r) and (u-r) have been produced and analysed using a Matlab code for the main sample as well as all five subsamples. Then a bimodal Gaussian fit to color distributions of data that have been carried out using minimum chi-square in Microsoft Office Excel. The results showed that the color distributions of the main sample and
... Show MoreThis study aims to identify the amount of the effect of the ability to learn the individuals within the organization on the accumulation of intellectual capital and the role it plays in improving the performance of the organization, and to achieve that, the researcher designed a questionnaire to collect data and information from the surveyed respondents and analyzed using SPSS software, the study concluded after testing hypotheses to have a direct impact between the capacity for organizational learning and the accumulation of intellectual capital, which in turn affects the accumulation of intellectual capital as a positive and direct impact on the performance of the organization, al
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