Abrham, Gebre (PhD)Wondmagegne, Dagne2020-03-052023-11-112020-03-052023-11-112019-07-04http://etd.aau.edu.et/handle/12345678/20854It‟s been a decade since post-tension system began to be applied in earnest to buildings worldwide. In the meantime, post-tension system has been used in various buildings as main structural system including tall buildings and it plays a role to overcome architectural limit of regular reinforced concrete buildings particularly in the realization of long span with shallower depth than other structural system. In Ethiopia the benefits of post stressing and particularly of post-tensioning flat slab in building construction yet to be fully recognized. In this project an attempt is made to assess the level of practice, the problems and achievements on the design and construction of post-tensioned flat slab in Ethiopia through distributing Questionnaires to be filled by professionals currently working on design and construction of buildings. The study suggests that measures shall be taken for the top identified factors hindering the wide application of post-tensioned flat slab in our construction industry widely like; Universities has not been covered the topics deeply in under-graduate sections, Shortage of research literatures, seminars and related design examples, Lack of experienced consultant, contractor and other engineering professionals and Lack of professionals and expertise. The basic concepts, principles and advantages of post-tensioned flat slab design are discussed and also this project attempt to compares the cost effectiveness of post-tensioned flat slab system with respect to reinforced concrete flat slab system. Both the systems are analyzed using ETABS which is based on the design methodology. The results indicate that post-tensioned flat slabs are cheaper than the reinforced flat slab systems. The analysis of post-tensioned flat slab is basically a trial and error process in an effort to reach the beast proportions. Manual computations of the analysis may take a time for engineers to arrive in best design. The study of the spreadsheet analysis of post-tensioned flat slab using Excel spreadsheet will be developing in this project. The design example is shown based on simple procedures by using design excel spreadsheet including ETABS demonstrations.en-USPrestressed concretePost-tensioned(PT)flat slabequivalent frame methodload balancing methodThesis