Concrete Beam EconomicsConcrete Beam Economics
Bob LawrenceBob Lawrence
Alan SchuetzAlan Schuetz
James GiancasproJames Giancaspro
Mark McDonnellMark McDonnell
AgendaAgenda
Problem StatementProblem Statement Concrete AssumptionsConcrete Assumptions Example of Spreadsheet ProgramExample of Spreadsheet Program Economics of a Concrete BeamEconomics of a Concrete Beam Alternative SolutionsAlternative Solutions ConcreteConcrete SteelSteel Economic Assumptions for Concrete and SteelEconomic Assumptions for Concrete and Steel Costs for Concrete and Steel BeamsCosts for Concrete and Steel Beams ConclusionConclusion
Problem StatementProblem Statement
To develop a cost analysis of a To develop a cost analysis of a concrete beam using multiple concrete beam using multiple parameters and compare the final parameters and compare the final cost with alternative methodscost with alternative methods
Economic Assumptions Economic Assumptions ConcreteConcrete
Concrete Beam Concrete Beam length shall be from length shall be from 0’ to 50’0’ to 50’
Water, Sand, Water, Sand, Aggregate and Steel Aggregate and Steel will have constant will have constant unit prices.unit prices.
The price of water The price of water came from the came from the Seattle Public Seattle Public Works.Works.
The prices for Sand, The prices for Sand, Steel and Steel and Aggregate were Aggregate were taken from taken from Engineering News Engineering News Report. Report.
The unit prices for The unit prices for Sand, Aggregate Sand, Aggregate and Steel are and Steel are calculated through calculated through a 20 city average.a 20 city average.
Concrete Economic Concrete Economic Assumptions Cont.Assumptions Cont.
Only three types of Only three types of concrete beams will concrete beams will be studied: Box, T, be studied: Box, T, and Land L
Concrete Beams Concrete Beams have a life span of have a life span of 50 years50 years
Labor cost will be Labor cost will be the same for all 3 the same for all 3 typestypes
Concrete beams Concrete beams require negligible require negligible maintenancemaintenance
At the end of 50 At the end of 50 years the beam years the beam has no salvage has no salvage value and is value and is recycledrecycled
Spreadsheet PresentationSpreadsheet Presentation
Spreadsheet EconomicsSpreadsheet Economics
10’ Beam10’ Beam Total Material Cost For A Box Beam$108.46 Total Material Cost For A T-Beam $54.07
Total Material Cost For A L-Beam $59.55 20’ Beam Total Material Cost For A Box Beam $496.02 Total Material Cost For A T-Beam $243.12
Total Material Cost For A L-Beam $271.65
Spreadsheet Econ. Cont.Spreadsheet Econ. Cont.
40’ Beam40’ Beam Total Material Cost For A Box Beam$2,515.91 Total Material Cost For A T-Beam $1,194.46
Total Material Cost For A L-Beam $1,388.35 50’ Beam50’ Beam Total Material Cost For A Box Beam$4,248.96 Total Material Cost For A T-Beam $2,049.36
Total Material Cost For A L-Beam $2,325.37
AlternativesAlternatives
Steel BeamsSteel Beams WoodWood Plastic LumberPlastic Lumber
Alternative Cont.Alternative Cont.
We only considered Steel because We only considered Steel because Plastic Lumber is still in the Plastic Lumber is still in the developmental stage and the developmental stage and the amount of Wood needed to hold an amount of Wood needed to hold an equal load is impractical equal load is impractical
ConcreteConcrete
BenefitsBenefits– Cheap MaterialsCheap Materials– Can hold same Can hold same
load as Steelload as Steel– DurableDurable– Low MaintenanceLow Maintenance– No Finishing No Finishing
RequiredRequired
NegativesNegatives– Shorter life spanShorter life span– Doesn’t allow for Doesn’t allow for
taller structurestaller structures– Concrete cannot Concrete cannot
take tensile forcetake tensile force
SteelSteel
BenefitsBenefits– Long Life spanLong Life span– Has Salvage valueHas Salvage value– Allows for taller Allows for taller
structuresstructures– Works equally as Works equally as
well in tension and well in tension and compression compression
NegativesNegatives– High MaintenanceHigh Maintenance– More expensive More expensive
than concretethan concrete
Assumptions for Assumptions for Concrete/Steel Concrete/Steel
ComparisonComparison
Safety and Strength Safety and Strength for steel and for steel and concrete beams will concrete beams will be set equal so be set equal so there will be an there will be an even comparisoneven comparison
Installation cost for Installation cost for steel and concrete steel and concrete beams are the beams are the samesame
When disassembled When disassembled neither will have an neither will have an effect on the effect on the environment so environment so that will not be that will not be considered.considered.
Assume 3 Masons Assume 3 Masons can construct a can construct a concrete beam in 1 concrete beam in 1 hour (pre-molded)hour (pre-molded)
Assumptions Cont.Assumptions Cont.
Steel beam must be Steel beam must be painted every 7 painted every 7 years or they will years or they will rustrust
We will terminate We will terminate our economic our economic comparison at 49 comparison at 49 years so the study years so the study times will be equaltimes will be equal
MARR 10%MARR 10%
The spreadsheet The spreadsheet program assumes program assumes all steel is 60 ksi.all steel is 60 ksi.
The price of steel The price of steel is a national is a national average.average.
The current The current recycling value of recycling value of steel is $90.00/tonsteel is $90.00/ton
Steel BeamsSteel Beams
There are only two steel beam that There are only two steel beam that can hold the 10,000 lb. live and can hold the 10,000 lb. live and dead load we have specified for dead load we have specified for the concrete beamsthe concrete beams
They are the:They are the:
W36 - 848W36 - 848
W36 - 798W36 - 798
Materials Cost ComparisonMaterials Cost Comparison
Concrete BeamConcrete Beam 50’ in length50’ in length
Total Material Cost For a Box Beam $4,248.96
Total Material Cost For a T-Beam $2,049.36
Total Material Cost For a L-Beam $2,325.37
Steel BeamSteel Beam 50’ in length50’ in length W36- 798W36- 798
$25,935$25,935 W36- 848W36- 848
$27,560$27,560
Maintenance Concrete Maintenance Concrete
Concrete BeamConcrete Beam Maintenance cost is very near zeroMaintenance cost is very near zero
Maintenance Steel Maintenance Steel
Steel must be painted every 7 yearsSteel must be painted every 7 years Assume 2 painters can cover 3,600 sq. Assume 2 painters can cover 3,600 sq.
ft per dayft per day They are paid $.11 per sq. ft.They are paid $.11 per sq. ft. Paint cost $.05 per sq. ft.Paint cost $.05 per sq. ft. One beam’s cost are:One beam’s cost are:
Labor:Labor: $396$396
Paint:Paint: $90 $90
Labor Cost ConcreteLabor Cost Concrete
Labor Cost for Concrete and Steel Labor Cost for Concrete and Steel are the same except for the beam are the same except for the beam must be formed out.must be formed out.
Assume 3 masons per beamAssume 3 masons per beam Assume Mason Labor Rate: Assume Mason Labor Rate:
$27.52/hour$27.52/hour Cost per beam:Cost per beam:
$82.56$82.56
Salvage ValueSalvage Value
ConcreteConcrete Concrete has Concrete has
salvage value of salvage value of approximately approximately zerozero
SteelSteel 50’ Length50’ Length W36- 848W36- 848
Salvage Value: $1908Salvage Value: $1908 W36 - 798W36 - 798
Salvage Value: Salvage Value: $1795.5$1795.5
Cost ComparisonCost ComparisonPer 50’ BeamPer 50’ Beam
Concrete Annual Concrete Annual WorthWorth
Labor $8.33Labor $8.33 MaterialsMaterials
– BoxBox $428.72$428.72– TT $206.78$206.78– LL
$234.63$234.63 Salvage $0Salvage $0 Maintenance $0Maintenance $0
Steel Annual WorthSteel Annual Worth MaterialsMaterials
– W36- 848 $2616.84W36- 848 $2616.84– W36- 798 $2780.80W36- 798 $2780.80
Maintenance Maintenance – Both beams $238.73Both beams $238.73
SalvageSalvage– W36- 848 $1.72W36- 848 $1.72– W36-798 $1.62W36-798 $1.62
Total CostsTotal Costs
Total CostsTotal Costs ConcreteConcrete
– BoxBox -$437-$437– TT -$215.16-$215.16– LL -$243-$243
SteelSteel– W36- 848 -$3017.81W36- 848 -$3017.81
– W36- 798W36- 798 - -$2853.95$2853.95
ConclusionConclusion
The main purpose of our project The main purpose of our project was to set up a Spreadsheet that was to set up a Spreadsheet that calculates material prices for calculates material prices for concrete beamsconcrete beams
Although through comparison our Although through comparison our recommendation would be for recommendation would be for Concrete BeamsConcrete Beams