Manual for Design and Detailings of Reinforced Concrete to Code of ...

Version 2.3 May 2008(iii)(iv)least 135 o in anchorage. Nevertheless, for walls, links used to restrainvertical bars in compression should have an included angle of not morethan 90 o by Cl. 9.6.4 which is identical to BS8110 and not a ductilityrequirement;More stringent requirements in restraining and containing longitudinalreinforcing bars in compression against buckling by closer andstronger transverse reinforcements with hooks of bent angles ≥ 135 o ;Longer bond and anchorage length of reinforcing bars in concrete toensure failure by yielding prior to bond slippage as the latter failure isbrittle;Ensure failure by yielding hereinstead of bond failure behindLonger and strongeranchoragebar in tensionFigure 2.5 – Longer bond and anchorage length of reinforcing bars(v)Restraining and/or avoiding radial forces by reinforcing bars onconcrete at where the bars change direction and concrete cover is thin;Radial force by bartending to cause concretespalling if concrete isrelatively thinRadial force by barinward on concretewhich is relatively thickFigure 2.6 – Bars bending inwards to avoid radial forces on thin concrete cover(vi)Limiting amounts of tension reinforcements in flexural members asover-provisions of tension reinforcements will lead to increase of7