Concrete Beam Economics
Bob Lawrence
Alan Schuetz
James Giancaspro
Mark McDonnell
Agenda
Problem Statement
Concrete Assumptions
Example of Spreadsheet Program
Economics of a Concrete Beam
Alternative Solutions
Concrete
Steel
Economic Assumptions for Concrete and Steel
Costs for Concrete and Steel Beams
Conclusion
Problem Statement
To develop a cost analysis of a concrete
beam using multiple parameters and
compare the final cost with alternative
methods
Economic Assumptions
Concrete
Concrete Beam
length shall be from
0’ to 50’
Water, Sand,
Aggregate and Steel
will have constant
unit prices.
The price of water
came from the
Seattle Public Works.
The prices for Sand,
Steel and Aggregate
were taken from
Engineering News
Report.
The unit prices for
Sand, Aggregate
and Steel are
calculated through a
20 city average.
Concrete Economic
Assumptions Cont.
Only three types of
concrete beams will
be studied: Box, T,
and L
Concrete Beams
have a life span of
50 years
Labor cost will be
the same for all 3
types
Concrete beams
require negligible
maintenance
At the end of 50
years the beam has
no salvage value
and is recycled
Spreadsheet Presentation
Spreadsheet Economics
10’ 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.
40’ 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’ 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
Alternatives
Steel Beams
Wood
Plastic Lumber
Alternative Cont.
We only considered Steel because
Plastic Lumber is still in the
developmental stage and the amount of
Wood needed to hold an equal load is
impractical
Concrete
Benefits
–
Cheap Materials
–
Can hold same load
as Steel
–
Durable
–
Low Maintenance
–
No Finishing
Required
Negatives
–
Shorter life span
–
Doesn’t allow for
taller structures
–
Concrete cannot take
tensile force
Steel
Benefits
–
Long Life span
–
Has Salvage value
–
Allows for taller
structures
–
Works equally as
well in tension and
compression
Negatives
–
High Maintenance
–
More expensive than
concrete
Assumptions for
Concrete/Steel Comparison
Safety and Strength
for steel and
concrete beams will
be set equal so
there will be an
even comparison
Installation cost for
steel and concrete
beams are the same
When disassembled
neither will have an
effect on the
environment so that
will not be
considered.
Assume 3 Masons
can construct a
concrete beam in 1
hour (pre

molded)
Assumptions Cont.
Steel beam must be
painted every 7
years or they will
rust
We will terminate
our economic
comparison at 49
years so the study
times will be equal
MARR 10%
The spreadsheet
program assumes
all steel is 60 ksi.
The price of steel is
a national average.
The current
recycling value of
steel is $90.00/ton
Steel Beams
There are only two steel beam that can
hold the 10,000 lb. live and dead load
we have specified for the concrete
beams
They are the:
W36

848
W36

798
Materials Cost Comparison
Concrete Beam
50’ 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 Beam
50’ in length
W36

798
$25,935
W36

848
$27,560
Maintenance Concrete
Concrete Beam
Maintenance cost is very near zero
Maintenance Steel
Steel must be painted every 7 years
Assume 2 painters can cover 3,600 sq.
ft per day
They are paid $.11 per sq. ft.
Paint cost $.05 per sq. ft.
One beam’s cost are:
Labor:
$396
Paint:
$90
Labor Cost Concrete
Labor Cost for Concrete and Steel are
the same except for the beam must be
formed out.
Assume 3 masons per beam
Assume Mason Labor Rate: $27.52/hour
Cost per beam:
$82.56
Salvage Value
Concrete
Concrete has
salvage value of
approximately zero
Steel
50’ Length
W36

848
Salvage Value: $1908
W36

798
Salvage Value: $1795.5
Cost Comparison
Per 50’ Beam
Concrete Annual Worth
Labor $8.33
Materials
–
Box
$428.72
–
T
$206.78
–
L
$234.63
Salvage $0
Maintenance $0
Steel Annual Worth
Materials
–
W36

848 $2616.84
–
W36

798 $2780.80
Maintenance
–
Both beams $238.73
Salvage
–
W36

848 $1.72
–
W36

798 $1.62
Total Costs
Total Costs
Concrete
–
Box

$437
–
T

$215.16
–
L

$243
Steel
–
W36

848

$3017.81
–
W36

798

$2853.95
$0.00
$500.00
$1,000.00
$1,500.00
$2,000.00
$2,500.00
$3,000.00
$3,500.00
Total Cost
BOX
T
L
848
798
Conclusion
The main purpose of our project was to
set up a Spreadsheet that calculates
material prices for concrete beams
Although through comparison our
recommendation would be for Concrete
Beams
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