Abstract Pouring of concrete underwater is necessary in the implementation of most in-shore, and off-shore structures. The pouring of underwater concrete is considered as a challenge for engineers, even during the design stage or during implementation and supervision. This is due to the fact that many precautions must be taken for the success of casting process. The most important precaution is to protect the fresh concrete during the casting process from the water to avoid the risk of washout of cement past and segregation of aggregates. Concrete can be placed underwater successfully though good design of concrete mix, and through choosing the most suitable method for placing of concrete. There are new techniques for underwater concreting such as grouted aggregate which is known as two-stage concrete (TSC) method which, as the name implies, consists of filling a form work with the coarse aggregate and then injecting the grout to fill the voids through pumping tubes extended to the bottom of the form. The main objective of the thesis is to present the capability of pouring the concrete underwater by using (TSC) method. A laboratory model was prepared and visually investigated and tested by extracting core samples, performing compressive test, tensile test and using ultrasonic pulse velocity test. From the obtained results it has been observed that, it is possible to pour concrete underwater by using two stage concrete in successful way, and it is recommended to develop this research by using different water cement ratios and cement sand ratios to get the optimum mix design and also, different types of aggregates which are available in local quarries.
منال فاروق النجار (2010)

كأي منشأ أخر يتعرض إلى أحمال خارجية وظروف جوية متغيرة مثل درجات الحرارة والرطوبة ومعدل سقوط الأمطار, تظهر أضرار على سطح الرصف الإسفلتي تقلل من كفائتة وأحيانا تجعله غير صالح للاستخدام. ومن هذه الحالة تُعتبر برامج الصيانة الخطوة الهامة والضرورية بعد إنشاء الطريق للمحافظة عليه. ولتحديد أفضل وسائل الصيانة و/أو إعادة التأهيل لا بد من إجراء تقييم لحالة الطريق لمعرفة الأضرار الموجودة بالطريق وأسبابها وجود منهجية لتقييم حالة سطح الطريق تساعد على تشخيص حالة سطح الرصف الإسفلتي بطريقة علمية وذلك ليتم الاختيار المناسب لطريقة الصيانة أو إعادة التأهيل تم في هذه الدراسة البحث والإطلاع على العديد من المراجع والطرق المتبعة في الولايات المتحدة الأمريكية وكندا لتقييم حالة سطح الرصف الإسفلتي وتحديد الطرق الأكثر تدقيقاًً والتي أمكن الحصول عليها وقد تم اختيار عدد ثلاث طرق أساسية لهذه الدراسة تم في هذا البحث تطبيق ثلاثة طرق (طريقة نورث كالورينا, وطريقة أوهايو, وطريقة الجمعية الأمريكية للمقاييس واختبارات الموادASTM)) ) لتقييم حالة سطح الرصف الإسفلتي على العديد من القطاعات النموذجية والتي تم اختيارها من عدة طرق بجنوب الجماهيرية ومن خلال النتائج المتحصل عليها لتقييم العديد من الطرق المحلية بجنوب الجماهيرية وذلك باستخدام الطرق القياسية الداخلة بالدراسة تم مناقشة النتائج المتحصل عليها والمقارنة بينها وبين حالة سطح الرصف الإسفلتي الحالي اهتم الجزء الأخير من هذا البحث بتقديم خلاصة للعمل الذي تم في هذه الدراسة وكذلك تقديم مقترح مسودة منهجية لتقييم حالة سطح الرصف الإسفلتي للتطبيق داخل الجماهيرية, ويقدم في الختام توصية بالإجراءات المكملة لهذا البحث. Abstract As any other structures subjected to external loads and environmental changes as temperature, humidity and intensity of rainfall that reduce it is performance and sometimes it becomes uncomfortable and unsafe for use. And programs of a maintenance is important and necessary after construction of the road to keep it convenient for use. An evaluation of road condition must be proceeded before the maintenance to determine the distresses and its causes in order to know the required remedies, to promote level of services for the road and to provide safety and comfortability, and maintain road network and allocate its expenses earlier to elongate its design life. A specific techniques for maintenance should be followed firstly for of asphaltic pavement surface condition to lead to an appropriate choice of the road maintenance or rehabilitation.In this study, several methodologies were studied and reviewed such as the methods used in the United States and Canada for the evaluation of the asphaltic pavement surface condition and methods with the most details and that could be obtained where have been selected (North Carolina, Ohio, and American Society of standards and testing materials method (ASTM)).The selected methods were applied to evaluate the asphaltic pavement surface condition on many typical sections of roads in dry and hot region in south of Great Jamahiriya.From the results obtained for the evaluation of many local roads in south of Great Jamahiriya, using the selected methods in this study, have been discussed and compared with the existent condition.A summary of the work done in this study and the proposal of draft methodology for evaluation of asphaltic pavement surface condition to be applied in Great Jamahiriya, and finally present recommendations for complement actions of this research.
الهاشمي محمد عبد النبي (2010)

This document presents recommended methods and procedures for measuring, mixing, transporting, and placing heavyweight concretes that are used principally for radiation shielding in nuclear construction. Also covered are recommendations on cement, heavy- weight aggregates, water, and admixtures. Mixture proportioning of heavyweight concrete is discussed. Mixing equipment, form construction, placing procedures, and methods of consolidation are described. Quality control, inspection, and testing are empha- sized, and a list of references is included. Preplaced heavyweight concrete is not discussed in this version of 304.3R. It is covered in the 2004 version of the document.
Hakim S. Abdelgader (12-2020)