الفهرس 
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Abstract
The main objective of this thesis was to study the behavior of headed bars lap splices in tension zones in reinforced concrete wide beams. The effect of several variables affecting the behavior of flexural members with lap splice in tension was studied. An experimental program was conducted on eight simply supported reinforced concrete beams. All tested beams had the same dimensions (400 mm x 200 mm x 2400 mm), concrete strength (42 N/mm2), the same longitudinal reinforcement ratio (j.1= 0.673%), and the values of clear concrete cover and relative head area were kept constant as 26 mm, and 6.96 respectively. All beams were tested using four points loading, until failure occurred. The main variables studied were: 1- Lap splices length (27, 15.5, and 8 times the bar diameter (db)) with a constant cut off ratio value 100%. 2- Stirrups spacing in lap splice zone 190mm, 90mm, and 45mm (1.15, 0.55, and 0.27 effective depth of the beam in the lap splice zone, respectively) with a constant lap length of 15.5 times the bar diameter (db). 3- Cut off ratio at defInite section (0.0% (No splice), 50%, and 100% of tensile reinforcement area) for constant lap length 15.5 times the bar diameter (db). Test results are illustrated and discussed briefly. Some of outcome conclusions which the results illustrate may be summarized as follows for the dimensions and reinforcement used in the present study: 1- The behavior of ordinary wide beam without splice can be achieved in spliced beams with 100% cut off ratio when the lap splice length equals to 27 db without using any transverse reinforcement, or when the lap length equals to 15.5 db using transverse reinforcement having spacing equal to 45mm (i.e. S=0.27 d), or when spliced beams with 50% cut off ratio when the lap splice length equal to an 15.5 db without using any transverse reinforcement. 2- In spliced beams with the lap splice length 15.5 db, 100% cut off ratio, and provided with transverse reinforcement (stirrups) for the spliced zone, the mode of failure changed from brittle (side blowout failure) to flexural . 3- For the same value of the lap splice length (15.5 db), without the use of transverse reinforcement at the spliced zone, the change of cut off ratio from 50% to 100% caused a reduction in ductility, ultimate load capacity, and changed the mode offailure from ductile flexural failure to brittle (side blowout failure) one. 4- Spliced beams with 100% cut off ratio, with lap length (15.5 db, and 8 db), and without transverse reinforcement resulted in a brittle side blowout failure.