1. Estimating the Cost of a Concrete Pad & Rebar (Revised: 2-21-2017)
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of a Concrete Pad & Rebar (Revised: )
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2. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Some of the most common uses of concrete include footings and slabs.
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3. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Driveways and Sidewalks
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4. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Floors
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5. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Retaining Walls
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6. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Piers
This pier shows a concrete column mounted above a CMU base
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7. Common Uses of Concrete
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Common Uses of Concrete
Columns
Concrete is also used for structural beams
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8. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Concrete –
Concrete is made of 4 main ingredients:
Gravel – Coarse Aggregate
Sand – Fine Aggregate
Portland Cement – Binds the ingredients together
Water – Activates the chemicals in the Portland cement
Admixtures – Often added to change properties such as hardness, curing time, color, etc.
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9. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Concrete –
Concrete does not dry, it hardens, or cures through a chemical process called hydration.
Hydration is a chemical reaction that takes place between the compounds in Portland Cement and water. In essence, the water actually becomes part of the concrete.
This process allows concrete to harden while submerged underwater.
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10. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Reinforced Concrete
Tensile Strength – The resistance of a material to being
pulled apart.
Compression Strength – The ability of a material to
resist being crushed.
Concrete has very high compressive strength
Concrete has very low tensile strength
Steel has very high tensile & compressive strength.
Reinforced Concrete – Concrete with steel bars running through it. The best of both worlds!
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11. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Reinforcing Bar
Steel rebar (Reinforcement bar) is added to increase the tensile strength of concrete.
The steel grid shown is made of rebar wired together
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12. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Reinforcing Bar
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13. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Reinforcing Bar
Rebar is also used to pin one structural element to an adjacent element.
Wood forms –
Used to hold concrete in place as it cures. Forms are removed afterwards
A concrete wall will eventually be poured over the rebar shown
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14. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Cost Estimation
Due to its strength, concrete is a valued part of any construction project, and also one of the costliest parts of a building. In order for a builder to determine the feasibility of building a structure, an accurate estimate of the cost to build the structure must first be developed. In the activity you are about to complete you will calculate the cost of building a concrete slab with reinforcement bars (rebar) included.
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15. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Cost Estimation
Estimation is a forecast of the cost of building a project.
Estimates are prepared at different intervals during the design phase of a project.
The first 2 Estimates are called:
Conceptual Design Estimate – Rough Estimates of costs (Taken from preliminary drawings of the project)
Construction Document Estimates – Accurate costs are taken from information provided on final plan drawings
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16. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Cost Estimation
The final phase of Cost Estimation is the Bid Phase, which is where actual costs for all aspects of the building are totaled. The following items are included in a final bid. Quantity take-offs (Amount of materials needed and their costs) Indirect costs (Shipping of materials, insurance, permit costs etc.) Labor (Number of workers needed and related costs) Profit margin – (How much profit to make off the project) Equipment costs – (Rental, Purchases, and leases) Subcontractor quotes – (Subcontractors perform specialty work on projects…Plumbers, Electricians, Masons, Roofers etc.) These estimates are usually organized and calculated using specialized Estimation software
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17. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Cost Estimator
Cost Estimates are produced by individuals called Estimators.
Estimators are specialist in developing cost information for building projects
Most estimators are employed in the construction industry.
Most estimators have a 2 or 4 year degree in estimation or project management, and have gained experience through working in the building and construction industry to become familiar with building materials and processes.
Estimators are typically employed by
Private Builders
Project Management Companies
Construction Contractors and/or sub-contractors
Design professionals (Architectural and engineering firms
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18. Activity - In this activity you will calculate:
The amount of concrete required for a concrete slab
The amount of rebar need for a slab
Forms needed to hold concrete while it cures
The number of bricks and amount of mortar needed to construct a brick wall.

19. How Much Will the Concrete Cost?
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
How Much Will the Concrete Cost?
Concrete is sold by volume and measured in cubic yards (yd3).
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20. Estimating the Cost of a Pad
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of a Pad
Pad size = 16 ft x 18 ft floor
4 in. thick
Convert all units to ft
16 ft, 18 ft, .333 ft
Calculate volume (L x W x t)
Convert ft3 to yd3
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21. Estimating the Cost of a Pad
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of a Pad
Concrete is typically sold in increments of ½ yd3 $98/ yard3 x 4.0 yards3 = $392
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22. Estimating the Cost of the Pad
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of the Pad
Rebar
Placed every two feet (max.) on a grid
Sold in 10 ft lengths
Must be lapped 6 in. to maintain strength
Maintain a 3 in. edge distance
6 in. lap
3 in. edge dist.
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23. Estimating the Cost of the Pad
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of the Pad
Rebar
3 in. edge dist.
6 in. lap
How many 10 ft pieces of rebar are needed? 38
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24. Estimating the Cost of the Pad
Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Estimating the Cost of the Pad
Rebar
Each piece of #4 rebar costs $4.78.
38 x $4.78 = $181.64
Other associated costs include material for forms, gravel, and labor.
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Copyright 2010

25. Estimating the Cost for the Concrete Pad
Civil Engineering and Architecture
Unit 2 – Lesson 2.2 – Cost and Efficiency Analysis
Image Resources
Microsoft, Inc. (n.d.). Clip art. Retrieved March 18, 2009, from
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