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 corrosion parameters and pitting susceptibility respectively. The change in the microstructure and morphology of the CSRB after polarization in the simulate concrete solution was studied using optical and atomic force microscopes. The results show that the corrosion rate of the CSRB in artificial concrete greatly increases with the existence of CO2 gas and highly depends on its concentration in the range 0.03 to 2.0% .No sign for pitting corrosion is recorded at all CO2 concentrations and the general corrosion is the main problem in the conditions under consideration.
Conventional concretes are almost unbending, and even a small amount of strain potential leaves them brittle. This lack of bendability is a major source of strain loss, and it has been the main goal behind the development of bendable concrete, often known with engineered ce ment composites, or ECC. This form of concrete has a lot more flexibility than regular concrete. Micromechanical polymer fibers are used to strengthen ECC. In most cases, ECC uses a 2% amount of thin, separated fibers. As a result, bendable concrete deforms but unlike traditional concrete, it does not crack. This study aims to include this kind of concrete, bendable concrete, which can be used to solve concrete problems. Karasta (CK) and Tasluja (CT) Portland Lime
... Show MoreNon-prismatic reinforced concrete (RC) beams are widely used for various practical purposes, including enhancing architectural aesthetics and increasing the overall thickness in the support area above the column, which gives high assurance to services that this will not result in the distortion of construction features and can reduce heights. The hollow sections (recess) can also be used for the maintenance of large structural sections and the safe passage of utility lines of water, gas, telecommunications, electricity, etc. They are generally used in large and complex civil engineering works like bridges. This study conducted a numerical study using the commercial finite element software ANSYS version 15 for analysing RC beams, hol
... Show MoreThis paper introduces an experimental study on the behavior of confined concrete filled aluminum tubular (CFT) column to improve strength design, ductility and durability of concrete composite structures under concentrically loaded in compression to failure. To achieve this: seven column specimens with same concrete diameter 100mm and without steel reinforcement have been examined through experimental testing, which are used to study the effects of the thickness of the aluminum tube encased concrete ( thickness : 0mm, 2mm, 3mm, 4mm and 5mm with same length of column 450mm), length of column (thickness 5mm and length of column 700mm) and durability (thickness 5mm and length of column 450mm) on the structural behavior of &
... Show MoreTo accommodate utilities in buildings, different sizes of openings are provided in the web of reinforced concrete deep beams, which cause reductions in the beam strength and stiffness. This paper aims to investigate experimentally and numerically the effectiveness of using carbon fiber reinforced polymer (CFRP) strips, as a strengthening technique, to externally strengthen reinforced concrete continuous deep beams (RCCDBs) with large openings. The experimental work included testing three RCCDBs under five-point bending. A reference specimen was prepared without openings to explore the reductions in strength and stiffness after providing large openings. Openings were created symmetrically at the center of spans of the other specimens
... Show Moreتعد الضريبة مصدراً مهماً لتحقيق الاهداف الاقتصادية والاجتماعية والسياسية للدولة ولذلك فان مشكلة التهرب الضريبي تعد اهم المشاكل التي ينبغي معالجتها من خلال معرفة اسبابها . ان وجود مشكلة التهرب الضريبي في العراق يرتبط بمجموعة من الاسباب والدوافع الكامنة وراء ظهور هذه المشكلة والتي لا نستطيع ان نلقي بتباعها على تخلف النظام الضريبي من حيث تشخيص الاختلالات في الادارة الضريبية تارة بل يجب ابراز عيوب التشريع الض
... Show Moreدور طلاب النور في الحياة السياسية التركية
الأهمية :
التخطيط بالمعنى العام مارسته بعض الجماعات ، وكثير من الأفراد عبر العصور فهم حاولوا أو يحاولون التحكم في مستقبل حياتهم أو حياة أبنائهم ، وقد حدثنا التأريخ عن بعض التجارب لمواجهة الأزمات والكوارث التي هددت بعض الشعوب ، ولعل قضية سيدنا يوسف عليه السلام وهي تشير الى خطته لمواجهة المجاعة المنتظرة ، ومقوماتها حسن التخزين وضبط الأستهلاك وفترتها الزمنية ، فضلاً عن أمثلة تاريخية لموا
... Show MoreThe re-insurance of the same important role in the development programs and activities that reinsurance companies and their level of development and the mechanisms of action and the laws that govern the relationship between the re-insurance companies and direct companies reflect the cultural level and degree of progress of any country. &n
... Show Moreدراسة التفكير الاستراتيجي وأبعاده وأثره في تمكين الموارد البشرية