![]() In this thesis parametric study was performed where compressive strength of concrete (f’c), yield strength of the reinforcing bars (fy) and bar diameters were the parameter. ![]() In this study we reviewed ACI (2002), BNBC (1993), AASHTO (2007), CEBFIP Model (1990) and EURO Code 2(2003) design codes and compared the variation of lap splice length. Various design codes have provided many laws to calculate lap splice length. In this study tension and contact lap splices are considered. Non-contact lap-spliced bars should not be spaced too far apart. Contact splices in which the bars touch and are wired together are preferred because they are more secure against displacement during construction. One is contact and the other one is non contact. The length of the lap varies depend on concrete strength, the rebar grade, size, and spacing. A lap is when two pieces of rebar are overlapped to create a continuous line of rebar. Properly designed splices are a key component in a well-executed design. Splices of reinforcing bars are unavoidable. Just as it is physically impossible to place all concrete in one continuous operation, it is impossible to provide full-length, continuous reinforcing bars throughout any sizeable structure. Dept.Due to practical limitations, the actual structure must be built piece-by-piece, story-by-story, and connected together. Roberts-Wollmann, Carin Patton Hall, Virginia Tech Charles E. Virginia Polytechnic Institute and State University, Blacksburg 208 Patton Hall ![]() Kassner, Bernie 43 Performing Organizations: Virginia Transportation Research Council 530 Edgemont Road The analysis will assess the cracking at service level stresses and the conditions of the elements at strength level and incipient failure. The scope will include large-scale structural tests to assess the need for modification factors based on: bar size, hook type, distance between lapped bars, side cover, transverse tie reinforcement, multiple layers of reinforcing, reinforcement yield strength, and concrete strength. The objective of this work will be the development of recommendations for designing non-contact, hooked bar lap splices in precast substructure elements. Additionally, multiple layers of spliced reinforcement in tension is not explicitly covered in AASHTO. There is also little data for non-contact lap splices or the development length of hooked bars that are larger than #6 bars. While American Association of State Highway and Transportation Officials (AASHTO) does provide limits for lap-spliced straight longitudinal bars in flexural members, there is no guidance on the maximum offset distance between hooked bars serving as a lap splice. One strategy for reducing the closure pour length is to lap splice hooked bars in a non-contact fashion, which enables easier fit-up of members during construction. Furthermore, failures of these connections tend to be brittle, thus adequate development is important. Making these splices using large-sized bars for the flexural reinforcement can be challenging because the development length of straight reinforcement, particularly Class B tension lap splices that must be 1.3 times the ordinary development length, can make closure pours quite large. Often, these designs require innovative connection methods, such as reinforcing bars spliced in closure pours between precast pieces. There has been an increase in the design of bridge substructures using precast elements in order to accelerate construction. Development of Design Recommendations for Non-Contact, Hooked Bar Lap Splices for Large Reinforcing Bars
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