Australian reinforced masonry wall design

I think that they have found that individual bars are liable to axial buckling.

The ties mean that it acts more like a concrete column and the individual buckling is restrained.

General view on this is that for 190mm walls or smaller it is extremely difficult (if not impossible) to get two layers of bars and the ties between.

As for previously constructed wall, hey it is not a perfect world. Try working in the US where the masonry code has changed from allowing big bars with low stress to limiting the bar to small sizes (with higher stress). What works with the old code is a violation of the new code and vice versa. We can only move on and design better from now on.

csd

There is an AS/NZS code forum

Look up under Engineering Codes, Standards & Certifications.

csd

The issue is not whether you could count the wall bars as compression steel. We didn't do that. But the clause in the old code recognized the benefit of the bars (if you used .0015A) by allowing the use of the reinforced masonry capacity reduction factor rather than the crd for unreinforced masonry.

Yes you must use 0.45 if you don't have ties, i.e. 99% of the time.

Table 4.1 really should include this.

Personally I think 0.45 is a bit harsh...

I agree, harsh but true. We all know that strength will be improved with reinforcement but the current code doesn't recognise that.