Transcript Solid Stainless Steel Rebar

Improving Tomorrow’s Infrastructure:
Extending the Life of Concrete Structures with
Solid Stainless Steel Reinforcing Bar
Stainless Steel World America
2008 Conference
September 9 & 10, 2008
Presented by
Talley Metals a Carpenter Company
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Progresso, Mexico piers
• Functioning Pier
• Built over 70 years ago
(1937)
• Used stainless steel - 304L
• Still has an additional 30
year life expectancy
• Non-functioning pier
• Built 30 years ago
• Carbon steel rebar
The information and data presented herein are typical or average values and are not a guarantee of maximum or
minimum values. Applications specifically suggested for material described herein are made solely for the
purpose of illustration to enable the reader to make his/her own evaluation and are not intended as warranties,
either express or implied, of fitness for these or other purposes.
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Stainless Steel
• Achieves its corrosion resistant
characteristics through the formation of
an invisible chromium oxide (Cr2O3) film.
• This oxide forms, on the surface of the
material and creates a corrosion resistant
barrier.
• Stainless steel must contain a minimum
of 12% chromium in order to be
considered a true stainless.
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125
100
75
50
25
0
0
5
10
15
20
25
30
Chromium, Copyright
%
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Hot Rolling and Acid-Cleaning
• Product is hot worked to
size on a rolling mill,
prior to the deformation
pattern that is added to
the surface, then it is
shot blasted and acid
cleaned, to remove any
scale and allow a passive
oxide film to form.
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Reinforcing Bar Issues/ Concerns
• Deteriorating structures due to corrosion
– Salt environment in coastal regions
– Heavy de-icing areas
• Initial cost vs. Life Cycle Costs
– Need to base product selection on life cycle
costs, not budgetary costs
• Concern is growing in seismic regions
• Maintenance and repair costs
• Public inconvenience, especially in dense
traffic and limited access areas
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Current Market Demands/Issues
• Need for Solid Stainless Steel Rebar for its corrosion
resistance and strength
• Rising raw material costs for Nickel and Molybdenum
– Results in a negative impact on stainless steel rebar prices
• Lower priced stainless products are desired by bridge
engineers
• Must meet ASTM - A955 for strength and corrosion
resistance
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Stainless Steel Rebar Advantages
•
•
•
•
•
•
Superior corrosion resistance (chlorides)
Superior strength levels and durability
Outstanding ductility at high strength
Long life (100+ years)
Eliminates the need for any coatings
Cost competitive in a full life-cycle
projection
• Most stainlesses are non-magnetic for
MRI applications, deperming piers
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Life Cycle Cost Analysis (by NIDI)
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ASTM - A955/A955M – 07a
for Stainless Steel Reinforcing bar
Grade
Yield Strength
40 (280)
60 (420)
75 (520)
40,000
60,000
75,000
70,000
90,000
100,000
20
20
20
(min psi)
Tensile Strength
(min psi)
Minimum Elongation
(%)
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Typical Mechanical Properties
for Stainless Rebar Alloys
Alloy
UNS
Yield Strength Tensile Strength
Designation
(KSI)
(KSI)
% EL
% RA
EnduraMet 2205
S31803
95-110
130
25
65
EnduraMet 316LN
S31653
65-80
110
40
70
EnduraMet 32
S24100
85
125
45
50
EnduraMet 33
S24000
85
125
45
50
EnduraMet is a registered trademark of CRS Holdings, Inc., a
subsidiary of Carpenter Technology Corporation
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Typical Chemical Compositions for
Stainless Rebar Alloys
Alloy
UNS
Designation
%
Cr
%
Ni
%
C
%
N
%
Mo
%
Mn
EnduraMet 2205
S31803
22
6
<.03
0.17
3
2
EnduraMet 316LN
S31653
17
10
<.03
0.12
2.1
2
EnduraMet 33
S24000
17
3.5
0.04
0.3
0.5
14
EnduraMet 32
S24100
17
0.7
0.04
0.3
0.5
14
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Ease of Forming Stainless Steel Rebar
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Stainless rebar on deck –
Haynes Inlet Bridge, Oregon
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Cost savings opportunities using
solid stainless steel
• Longer life of structure
– Stainless steel rebar has demonstrated a life
expectancy of 100+ years.
• Reduced concrete cover
– Less concrete cover required with stainless
rebar, which reduces the deck weight.
• Reduced superstructure
– Reduced deck weight, results in a reduced
weight of the superstructure.
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Some construction projects using
Talley-produced stainless rebar
•
•
•
•
•
•
Haynes Inlet Slough Bridge in Oregon
Belt Parkway in NY City
Garden State Parkway in NJ
Driscoll Bridge in NJ
Lincoln Tunnel in NY
Woodrow Wilson Bridge (Washington,
DC)
• Deperming Piers (Norfolk Naval Yard)
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Using Stainless Steel Rebar
• Used in critical design areas
– Such as bridge decks, barrier walls, columns,
foundations, and ramps
• Minimal maintenance and/or repair costs
– Reduce out-of-service disruptions
• FHWA slogan
– Get in, get out, stay out!
• Life expectancy of 100+ Years
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Thank you for your interest in solid stainless steel
reinforcing bar. More information about Carpenter’s
products is available on this website including
technical datasheets about EnduraMet stainless and
the white paper. Go to Technical Articles and select
the August 2007 article “Improving Tomorrow’s
Infrastructure.”
To contact Carpenter, call 1-800-654-6543 in the U.S.
or refer to the Contact Us page for the location
nearest you.
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