الفهرس | Only 14 pages are availabe for public view |
Abstract A research program was conducted to assess the effect of confinement, size and steel fibers effect on flexural failure and strength of tension lapped splices bars in reinforced concrete beams with and without transverse reinforcement was investigated. 38- beam specimens were tested in this program, where reduced scale failure tests on simply supported four-pciint- bend beams of 10, 20 and 30 diameter of deformed longitudinal reinforcing bars located in the mid - span region with uniform bending moment. Beams with three different heights (150, 230 and 350 with( mm containing different steel fibers with volumetric fraction of 0.0, 0.5 and 1.0 %, and with or without transverse confinement. The results indicate the existence of significant size effect not only due to beam size but also due to lap splice size, but also due to lap splice size, which is found to be stronger for splices without confinement than that confined using stirrups and steel fibers. The results indicate the existence of significant consistent increase in average bond strength as the fib er content or number of stirrups increased. The crack width decreased as the fiber content or number of stirrups increased, in comparison with companion beams. Although the cracks in the beams with fibers or/and stirrups were generally smaller in size than the companion plain beams, they were larger in number. The ability. of beams with fibers or/and stirrups to develop a large number of small width cracks prior to failure is the main reason behind their ductile behavior. Tests also, indicate positive effects of the provided confinement on the bond strength of the tension lap splices and the mode of failure. |