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 MC 2 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 high- slump –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: 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: 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: 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 Concrete Work Pricing Notes Example 2—Office/Warehouse Building –Refer to Figure 11.12

Pricing Using MC 2 ICE Software Items measured in takeoff –Automatically priced from the unit price catalogue –Can be modified Labor rates: refer to Figures and 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