Question

# A fully grouted reinforced concrete masonry wall, composed of 8 inch (7.63 in. effective) thick hollow...

A fully grouted reinforced concrete masonry wall, composed of 8 inch (7.63 in. effective) thick hollow concrete masonry units laid out in full bedding is reinforced with #6 (Ab = 0.44 in2 ) Grade 60 bars (fy = 60,000 psi) at 25 inches on center. Find the wall load capacity for pure compression and pure flexure conditions. The compressive strength of the masonry, f’m, is 2000 psi.

Capacity in pure compression,

P = A​​​​​​wall​​.f'wall + A​​​​​​steel​.f'steel

This calculation should be done for 1 foot width of wall.

Steel in wall is #6 at 25 inch centre to centre distance. Area of steel in 1 foot (12 inch) is = (12/25) x area of one #6 rebar

= (12/25) x 0.44

= 0.2112 sq. Inch

Area of wall = Gross area of wall - area of steel ( All for 1 foot)

= 7.63 x 12 - 0.2112

= 91.3448 sq. Inch

p = 91.3448 x 2000 + 0.2112 x 60000

= 195369.6 pound or 195.37 kips (per foot length of wall)