Bursting and Spalling in Pretensioned U-Beams - Ferguson ...

transversereinforcementwithin voidprojectiontransversereinforcementwithin webprojectionFigure 2.59 Transverse reinforcement in the end block of a Texas U-beam,divided into that provided within the projected areas of the void & the websIn light of the ambiguities in AASHTO LRFD, and the considerable effectresulting from how the transverse reinforcement is counted, two figures—Figures 2.60and 2.61—show the standard end-region reinforcement for the four U-beams alongsidespalling and lateral bursting code requirements. The former of these considers alltransverse reinforcement in end blocks; the latter neglects consideration of thereinforcement within the void projection of end blocks. This distinction only affects thecounting of provided reinforcement area for the Texas and Florida beams.For these figures, a 54-in. beam of each type was considered, with a prestressingforce consistent with that used in the experimental portion (78 – 0.5-in. strands). It shouldbe noted that the CEB-FIP Model Code (1990) does not require bursting reinforcementfor this beam. For the CEB-FIP spalling reinforcement, no length is given in the code inwhich the required reinforcement must be placed. For the sake of comparison with theDOT standard designs, an end-region design length of h/2 was assumed. Calculations foramount of reinforcement required by the various codes are presented in Appendix B.94