Transcript Chapter 11: PRICING Concrete Work

Chapter 11
Pricing Concrete Work
Objectives
• Upon completion of this chapter, you
will be able to:
– Describe the job factors and the labor and
management factors that influence the cost
of concrete work
– Calculate and compare the costs of
different concreting methods
Objectives (cont’d.)
– Describe the factors that should be
considered when pricing concrete
materials
– Identify the factors to consider when
pricing formwork systems
– Calculate the price per unit area of form
systems
– Describe the factors that influence the
price of reinforcing steel
Objectives (cont’d.)
– Price miscellaneous items associated with
concrete work
– Complete the recap and pricing of concrete
work using manual methods
– Use Excel spreadsheets to price concrete
work
– Adjust prices and productivities in MC2 ICE
estimates
Cast-in-Place Concrete Work
Generally
• Concreting activities categories:
– Supply and placing concrete
– Construction and removal of formwork
– Supply and placing reinforcing steel
– Miscellaneous associated items
Supplying and Placing Concrete
• Costs include:
– Cement
– Sand
– Aggregate
– Water
– Equipment to mix and transport
• Concrete mixing and batching plant
• Ready mix concrete
Productivity Placing Concrete
• Cost of placing concrete in required
position
– Depends on a large number of factors
• Job factors
• Labor and management factors
Job Factors
• Method of placing concrete
– Pouring
– Hand-operated or powered buggies
– Concrete pumps
– Conveyors
– Combination of two or more methods
• Ready-mixed concrete
– Delivery rate
Job Factors (cont’d.)
• Properties of the concrete to be placed
– Higher-slump mixtures: sloppier
– Lower-slump mixtures: flow more easily
– Superplasticizer additives: produce highslump
– Fiber reinforced concrete: improves tensile
strength
Job Factors (cont’d.)
• Size and shape of concrete structures
– Large volume concrete “pours” cost less
– Placing concrete continuously is more
economical
– Size and shape will impact placing method
• Amount of rebar in forms
– Large amounts may call for high slump
Job Factors (cont’d.)
• Concreting productivity rates
– Most contractors maintain a database of
historic unit prices
• Previous cost reports
• Site observations of work in progress
– Refer to Figure 11.1
Concrete Materials
• Prices for ready-mixed concrete
– Obtained from local supplier price list
• Quotations usually have conditions and extra
charges attached
• Several issues to consider
• Waste factors
– Allowances for waste and spillage
• Increase takeoff quantities or raise price
Formwork
• Wide range of methods
– Number of costs to consider:
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Building and maintaining the form system
Setting up the system
Removing the system
Other costs (e.g., transportation, storage, etc.)
Formwork Productivity
• Items that impact productivity and cost:
– Potential for reuse of a form system
– Complexity of formwork design
– Use of “fly forms” (“gang forms”)
– Number of form ties required for a system
• Formwork productivity rates:
– Refer to Figure 11.3
Pricing Formwork Materials
• Material costs include:
– Rental or purchase cost of all components
– Form hardware cost
• Total system price:
– Expressed as a price per square foot or
square meter of formwork
• Calculating price:
– Use of computer programs
Reinforcing Steel
• Includes welded wire mesh and reinforcing
bars
– Additional cost constituents:
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Rebar shop drawings
Raw steel bars
Handling, cutting, bending, and identifying rebar
Transporting the bars to the site
Spacers, chairs, saddles, and ties used
Labor cost of installation
Reinforcing Steel (cont’d.)
• Reinforcing steel—installation
productivity:
– Affected by:
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Size and lengths of the reinforcing bars
Shapes of the bars
Complexity of the concrete design
Amount of tolerance allowed in spacing of bars
Amount of tying required
Miscellaneous Concrete Work Items
• Concreting operations
– Several associated items
• Pricing miscellaneous concrete
materials
– May not be exactly clear
• Example: items of setting slab screed
Wage Rates
• Basic hourly wages
– Equipment operator: $40.00
– Labor foreman: $33.00
– Laborer: $30.00
– Cement finisher: $37.00
– Carpentry foreman: $41.00
– Carpenter: $38.00
– Rebar rodman: $43.00
Examples
• Concrete Work Recap and Pricing
Notes Example 1—House
– Refer to Figures 11.9 through Figure 11.11
• Concrete Work Pricing Notes Example
2—Office/Warehouse Building
– Refer to Figure 11.12
Pricing Using MC2 ICE Software
• Items measured in takeoff
– Automatically priced from the unit price
catalogue
– Can be modified
• Labor rates: refer to Figures 11.13 and 11.14
• Material prices: refer to Figure 11.15
Using the Drill Down Navigation Bar
• Estimate Maintenance window
– Values may be changed
• Set up to show all items measured in takeoff
– May be useful to focus on specific parts of
the estimate
• Refer to Figure 11.17
Summary
• Main categories for pricing concrete:
– Supply and placing concrete
– Construction and removal of formwork
– Supply and placing reinforcing steel
– Miscellaneous items associated with
concrete work
• Productivity:
– Influenced by several factors