This paper provides experimentally determined estimates of the scale of fluctuation of the principal variables employed in modeling chloride-induced corrosion for reinforced concrete; i.e., the surface chloride content (Cs) and apparent diffusion coefficient (Dapp). The estimation of the scale of fluctuation, θ, is based on the analysis of experimental data recorded on a bridge in South East Ireland prior to its extensive rehabilitation in 2007. In determining the scale of fluctuation the paper considers two commonly used methods; i.e., the maximum likelihood method and the autocorrelation curve-fitting method. The reliability of both methods is discussed. Introduction of the kriging statistical interpolation method is demonstrated to improve the reliability of the estimates of the scale of fluctuation. The results obtained from the analysis are compared with values in the literature proffered by other researchers. arabic 16 English 119
Omran Kenshel(1-2013)

Prediction of the present and future state of Reinforced Concrete (RC) structures suffering from chloride-induced corrosion is important if proper planning for inspection and maintenance is to be made. The majority of research studies have thus far focused on the diffusion process of chloride ions through the concrete cover, the time to corrosion initiation and on the prediction of the surface condition of the structure. However; practical evidence and theoretical analysis suggests that many structures can tolerate considerable corrosion damage without serious reduction to their load carrying capacity. Therefore, visual impression-based maintenance is not an optimum solution particularly when financial resources are limited. To support this notion, accurate models are needed to predict the deterioration rate of the structural load carrying capacity over time. This paper uses existing empirical RC deterioration models to predict the loss in the load carrying capacity of a typical RC T-beam using a reliability based approach. The approach takes into consideration the spatial variability of the deterioration parameters, thereby demonstrating the importance of its inclusion in any such analysis. arabic 13 English 97
Omran Kenshel(1-2009)

الموانئ هي المنافذ الرئيسية للتجارة الداخلية والخارجية للدول، وتؤدي دوراً مهماً جداً في النمو الاقتصادي لكثير من الدول المتقدمة؛ حيث تعمل بوابات تمر من خلالها التجارة الخارجية، مثل استيراد المواد الخام ومن ثم تصنيعها وتصدير الجزء الكبير منها بعد التصنيع، أما بالنسبة إلى الدول النامية فإن اقتصاد معظم هذه الدول يعتمد على التجارة المنقولة بحراً ومن ثمّ على الموانئ، ولا تستطيع أي دولة من الدول النامية أن تستورد المنتجات المصنّعة والبضائع الأساسية لسد احتياجاتها؛ وكذلك تصدير المواد الخام التي تمكنها من الحصول على العملات الأجنبية من دون مرافئ فيها أو بالقرب منها ولهذا فان هذا البحث يقوم بدراسة الموانئ بصفة عامة من حيث تصنيفها ومكوناتها الإنشائية وبصفة خاصة دراسة حواجز الأمواج وأنوعها ومميزاتها وعيوبها ولمعرفة مكوناتها لما لها من تأثير على حركة الملاحة بالموانئ وتسليط الضوء على الموانئ الليبية وتصنيفها والظروف البحرية والمناخية المؤثرة عليها ودراسة المشاكل التصميمية لبعض الموانئ الليبية والظواهر التي طرأت على حواجز الأمواج والحلول المقترحة لهذه المشاكل Abstract Ports are the main outlets for internal trade and foreign countries, and lead a very important role in the economic growth of many developed countries; where she works gates pass through foreign trade, such as import raw materials and then manufactured and exported a large part of them after processing, but for developing countries, the economy of most of these countries depends on the seaborne trade and then the port, nor can any of the developing countries to be imported manufactured products and essential goods to meet their needs; as well as export of raw materials to be able to get foreign currency without ports where or near.Therefore, this research is studying ports generally in terms of classification and components construction and particularly the study of breakwaters and Onoaha and advantages and disadvantages and knowledge components because of their impact on the traffic in ports and shed light on Libyan ports, classification and sea conditions and climatic influence them and study the problems design of some Libyan ports and phenomena that have occurred on breakwaters and proposed solutions to these problems.
سعاد عمرو امحمد سندوقو (2013)