Minimum Reinforcement Ratio

[MOOK]

Minimum reinforcement ratio in masonry walls with single layer of steel

ƍ = As/(b.d) or

ƍ = As/(b.t)

b = width of wall, t = thickness of wall, d = t/2

In concrete there is no big difference in the two equations but in masonry there is big difference, so which one is the correct one?

 

[MA_PE]

Minimum reinforcement ratio in masonry walls with single layer of steelƍ = As/(b.d) or

ƍ = As/(b.t)

b = width of wall, t = thickness of wall, d = t/2

In concrete there is no big difference in the two equations but in masonry there is big difference, so which one is the correct one?

Wait a minute. Which minimum reinforcing, temperature and shrinkage steel or minimum reinforcing for flexure?

In concrete temperature and shrinkage is based on the gross area of concrete (b*t), but minimum flexural steel would be required to resist 1.2*cracking moment and subsequently would be based on d.

Sorry, I don't have a copy of the masonry code handy to see what they are looking for.

 

[McEngr]

Keep in mind for shearwalls it is the length of the gross wall.

 

[20-20]

Minimum reinforcement ratio in masonry walls with single layer of steelƍ = As/(b.d) or

ƍ = As/(b.t)

b = width of wall, t = thickness of wall, d = t/2

In concrete there is no big difference in the two equations but in masonry there is big difference, so which one is the correct one?

I don't believe there are any minimum reinforcing requirements for flexural design of masonry. ACI 530-05 2.3.4, ASD reinforced masonry, simply states "axial and flexural tension shall be resisted entirely by steel reinforcement"

There are minimum provisions for seismic requirements provided in ACI 530-05 1.14. These provisions are for the gross section wall properties, As/(bt)

 

[P/S Designer]

Minimum reinforcement ratio in masonry walls with single layer of steelƍ = As/(b.d) or

ƍ = As/(b.t)

b = width of wall, t = thickness of wall, d = t/2

In concrete there is no big difference in the two equations but in masonry there is big difference, so which one is the correct one?

ACI 530-05 section 2.33, page C-29 should give you the appropriate guidelines for masonry members in axial compression and flexure.