Stability of Singly Reinforced Walls  

Hi all,

NZS3101 11.2.5.2.1 limits the axial load on a singly reinforced wall to 0.015f’cAg if one is to use the simplified methods within the code to assess the wall stability.

Interestingly, the reinforced masonry code (NZS 4230) clause 7.3.4.8 allows for gravity load bearing non limited ductile or ductile walls (which I have interpreted has gravity load bearing nominally ductile walls) to have a much higher axial load.

A 140mm thick 12MPa nominally ductile reinforced concrete masonry wall with a 3m inter-story height can be deemed acceptable for 10x the axial load of an equivalent 30MPa reinforced concrete wall using the NZS 4230 code clause. 

Would someone be able to shed some light in to this discrepancy? 

Maybe the more current experimental data that is the basis of NZS3101 amendment A2 in 2008 have not reached the NZS4230 which was last ammended in 2006?

Thanks,
Poornaka 😊