Reinforced Concrete Design Examples, ACI Code 318-11

Calculate the allowable design axial load of a 12 in., square, short tied column reinforced with four number 9 bars. Ties are number 3 spaced at 10 inches. Given that f'c = 3.5 ksi and fy = 60 ksi.

 

Code used: ACI Code 318-11

A square tied column supports a dead load of 400 kips and live load of 200 kips. Design the column assuming a steel ratio of 4%, f'c = 5 ksi, and fy = 60 ksi. Also, design the necessary ties using ACI Code 318-11.

A simply supported beam with rectangular cross-section has the following parameters:

 

Width, b - 12 in

Effective Depth, d - 21.5 in

Total Depth, h - 24 in

Compressive Strength of Concrete, f'c - 4 ksi

Yield Strength of Shear Reinforcement, fyt - 60 ksi

 

Normal weight concrete

 

Check if this section is adequate for the following factored shear forces:

  1. V u = 10 kips
  2. Vu =  22 kips
  3. Vu =  60 kips
  4. Vu = 80 kips
  5. Vu = 130 kips

Code used: ACI Code 318-11

Find the design moment strength of a one-way slab given the following details:

 

Total Depth, h = 7 inches
Reinforcement - #6 Bars
Reinforcement Spacing, S = 8 inches
Compressive Strength of Concrete, f'c = 3 ksi
Yield Strength of Reinforcement, fy = 60 ksi

 

Code used: ACI Code 318-11

Design an interior rib of a concrete joist floor system given the following information:

 

Span of rib = 20 ft, simply supported
Uniform Dead Load (Excluding self weight) = 20 psf
Uniform Live Load = 90 psf
Compressive Strength of Concrete, f'c = 3 ksi
Yield Strength of Reinforcement, fy = 60 ksi

 

Code Used: ACI Code 318-11

Design a reinforced concrete footing to support a wall given the following design parameters:

 

Width of wall: 20 inches
Wall dead load including self-weight: 25 k/ft
Wall live load: 20 k/ft
Distance from final grade to bottom of footing: 6 ft
Normal weight concrete
Compressive strength of concrete: 4 ksi
Yield strength of reinforcement: 60 ksi
Allowable soil pressure: 5 ksf
Unit weight of concrete: 150 lb/ft^3
Unit weight of soil: 100 lb/ft^3

 

Code Used: ACI Code 318-11

Design a single square footing to support an interior square tied column given the following design parameters:

 

Width of Column: 18 inches

Column Reinforcement: (8) #9 bars

Column dead load: 250 k

Column live load: 200 k

Distance from final grade to bottom of footing: 4 ft

Normal weight concrete

Compressive strength of concrete: 4 ksi

Yield strength of reinforcement: 60 ksi

Allowable soil pressure: 5 ksf

Unit weight of concrete: 150 lb/ft^3

Unit weight of soil: 100 lb/ft^3

 

Code Used - ACI Code 318-11

Design the dowels required to ensure proper force transfer between column and footing given the following parameters:

 

Column Dimensions: 14 in x 14 in

Column Reinforcement: Tied column with (4) no. 11 longitudinal bars

Footing Size: 10 ft x 10 ft

Compressive Strength of Concrete, f’c = 4000 psi

Yield Strength of Reinforcement, fy = 60,000 psi

Axial Dead Load = 245 kips

Axial Live Load =  155 kips

 

Code Used - ACI Code 318-11

The table below shows footing numbers and associated dead and live loads. Determine the area of each footing foundation that is required for equal settlement if the usual live load is 20% for all of the footings, and the allowable net soil pressure is 6 ksf.

Design a plain concrete footing to support a wall given the following design parameters:

 

Width of wall: 16 inches
Wall dead load including self-weight: 15 k/ft
Wall live load: 11 k/ft
Distance from final grade to bottom of footing: 4 ft
Normal weight concrete
Compressive strength of concrete: 3 ksi
Allowable soil pressure: 5 ksf
Unit weight of concrete: 145 lb/ft^3
Unit weight of soil: 100 lb/ft^3

 

Code Used - ACI Code 318-11