B2. Anchorage of Slab Reinforcement at Upstand Beam

Code Compliance & Reference
This detail complies with HKRC2004 Clause 9.3.1.3 regarding the reinforcement at end supports for solid slabs (which include a reference to 9.2.1.7 regarding the anchorage of bars at a simply-supported end of a beam).

Comments

1. This detail is essentially the same as previous B1 details. The only differences are that both anchorages bent upward and the bottom slab reinforcement shall be crank at 1:12.
2. Why is the bottom slab reinforcement cranked for a upstand-beam connection, while the top slab reinforcement doesn’t need to be cranked for a downstand-beam connection? I don’t have a convincing answer. Maybe it’s because the top slab reinforcement is more important at edge (due to hogging moment) and hence no crank would be better. Maybe it’s because the bottom slab reinforcement at the edge of a slab has a higher chance to be larger than 10mm; it may clash with the beam reinforcement (when the slab bottom bar diameter is larger than the beam’s stirrups), hence it’d be safer to just crank the slab bottom bar up.
   

Blog note: Very busy last two weeks!