الفهرس | Only 14 pages are availabe for public view |
Abstract Reinforced concrete dapped-end beams are mainly used for precast element construction. Generally, the dapped end is recessed at their end parts and supported by columns, beam ledges, or corbels. The geometric discontinuity of dapped-end beams evokes a severe stress concentration at re-entrant corners that may lead to shear failure. Therefore, stress analysis is required at the re-entrant vicinity for the design requirement of these beams. Objectives were set and the research methodology was put forward to attain such objectives. This thesis summary describes the design of dapped ends of the precast concrete beam based on an experimental program to identify the reinforcement schemes’ effectiveness. In this research, four reinforced concrete dapped end beams with eight ends having a cross-section corresponding to a (400 mm) deep (200 mm) wide and 2m long. In the experimental program, four R.C. beams with eight different reinforcement schemes were prepared, cast, and tested up to failure and investigated in the experimental program: the PCI-1, PCI-2, Inclined Aₛ with welded plate, inclined Aₛ with Practical anchorage, inclined Aₛ with proper anchorage, 200% Aₛ with 50% Aₛₕ, 200% Aₛₕ with 50% Aₛ, and practical details under which reinforcement schemes were tested, is described in this Thesis summary. Four Dapped end beams specimens were prepared, cast, and tested up to failure. Finite element modeling was done to verify the results. The parameters were investigated: amount, arrangement & anchorage of flexural reinforcements, Shear Friction Reinforcement, and Hanger reinforcement at the dapped-end area. Finite element analysis using ANSYS was also conducted to predict the behavior of the dapped end beams. It has been found that the highest stress concentration factors occur at the re-entrant corners and their vicinity. the control specimen was following the PCI design handbook reinforcement arrangement. The results were presented on charts so as tables and discussed. During the thesis study, conclusions were drawn, and recommendations for future research and Engineering practice were suggested to improve the dapped end reinforcement scheme practices were recommended. |