new generation stainless steel as reinforcement bar
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NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
CONTENTS
Sl. No. Page No.
1 Introduction 2
2 Stainless Steel 4
3 Types of Stainless steel 5
4 Properties of Stainless steel 8
5 Life Cost Analysis of Stainless Steel 11
6 Advantages of Stainless steel 14
7 Applications of Stainless Steel 16
8 Conclusion 22
9 References 23
DEPARTMENT OF CIVIL ENGINEERING 1 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
1. INTRODUCTION
Construction builds the basic framework and infrastructure of a country, which stimulates
further economic, commercial and industrial activities. In building construction role of
steel is same as that of bones in a living being. Reinforced concrete has been used
successfully in the construction industry since the beginning of this Century. One of the
products traditionally used to reinforce concrete is plain carbon steel. At present a large
number of reinforced commercial buildings, domestic dwellings, marine structures,
bridges, etc., are starting to show serious signs of deterioration, particularly those over 30
years of age. This deterioration is mainly caused by corrosion of the reinforcement. This
carbon steel has low strength and poor resistance to corrosion. Hence, carbon steel
corrodes fast and reduces the load bearing capacity of the structure resulting in reduced
life and collapse of the structure in extreme case. This necessitates costly and time-
consuming repairs and maintenance of the structure
1.1 What Causes Corrosion?
Chloride ion is the main culprit. Corrosion of carbon steel rebars is greatly accelerated
when chlorides are present in the concrete (along with the requisite moisture and oxygen
levels to sustain the corrosion reactions). In some parts of the world, chlorides may be
incorporated into the original mix due to their presence in the sand, aggregate or water.
Most often, chlorides penetrate through the "cover" when the external surfaces of the
concrete are exposed to seawater, marine atmospheres or de-icing salts. When steel
corrodes, it forms an oxide layer. These corrosion products-oxides-have a larger volume
than the original steel. This expansion puts pressure on the concrete cover. Since the
concrete is already set and hard, it causes cracks as it expands to accommodate the larger
volume of steel inside. This is the basic phenomenon of cracking or spalling of any
concrete structure. Hence, carbon steel corrodes fast and reduces the load bearing
capacity of the structure resulting in reduced life and collapse of the structure in extreme
DEPARTMENT OF CIVIL ENGINEERING 2 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
case. This necessitates costly and time-consuming repairs and maintenance of the
structure
Deterioration of reinforced concrete caused by corrosion of the carbon steel reinforcing
bars (rebars) is a worldwide problem. Here are some pictures showing the deterioration of
structures due to carbon steel reinforcement
Several methods are currently employed in an attempt to reduce the corrosion of carbon
steel rebars.
Rebar coatings
Increased concrete cover;
Reduced water/cement ratios;
Corrosion inhibiting admixtures added to the concrete mix,
DEPARTMENT OF CIVIL ENGINEERING 3 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Cathodic protection;
Application of waterproofing membranes, penetrants and sealers on concrete
surfaces,
Electrochemical removal of chlorides.
These methods have their own advantages and limitations, but they all represent
secondary efforts to control the corrosion
However, there is increasing interest in the use of reinforcing materials that have
inherently good corrosion resistance, thus minimizing the need for maintenance and
monitoring of the structure. To address the problem at its source, we must focus attention
on the steel reinforcing bar before it becomes encased in the concrete.
In practice, stainless steel rebar has been used in many concrete structures to provide high
strength and long term resistance to the corrosive attack of chlorides from road salt and
harsh marine environments, as well as chlorides formed by concrete in which the rebar is
buried, and may be the preferred option for bridges that are inaccessible for future
maintenance (i.e. high traffic areas).
2. STAINLESS STEEL
Stainless steel is low carbon steel. Stainless is an alloy of iron with chromium content
over 10.5%. Chromium is the alloying element that imparts to stainless steel their
corrosion resistance qualities by combining with oxygen to form a thin,
invisible, chromium oxide protective film on the surface. This means improved corrosion
resistance, as can be seen in the Fig 1. (Reference 1)
In the event that the protective (passive) film is disturbed or even destroyed, in the
presence of oxygen in the environment, reform immediately and continue to give
maximum protection.
The protective film is stable and protective in normal atmosphere or mild aqueous
environments, but can be improved by higher chromium and by molybdenum, nickel and
other alloying elements. Nickel is added to enhance corrosion resistance and also to
DEPARTMENT OF CIVIL ENGINEERING 4 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
improve engineering properties (cold and hot working, bending, welding etc.). Addition
to molybdenum enhances resistance to pitting.
This film protective layer is Uniform, Stable, Tenacious, Continuous, Self-repairing and
Transparent
Effect Of Chromium
3. TYPES OF STAINLESS STEEL
Austenitic
Ferritic
Austenitic-Ferritic (Duplex)
Martensitic
Some of the commonly used grades of stainless steel for rebar applications are type
304,316(austenitic) and 2205(duplex). The alloy is selected based on mechanical
properties and the expected exposure or corrosivity of the service environment, i.e. the
level of corrosion resistance required.
DEPARTMENT OF CIVIL ENGINEERING 5 M.C.E Hassan.
Fig 1.Corrosion Resistance of Stainless steel
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
3.1 Austenitic
Austenitic is the most widely used type of stainless steel. It is made by adding nickel
(from 8 to 25 percent) and increasing the chromium level (from 17 to 25 percent).
Molybdenum can also be added (up to 7 percent) to increase the corrosion resistance.
These stainless steels are not magnetic. They can be easily welded. Austenitic have
exceptional resistance to high and low temperatures. The most common example is Type
304 (S30400)-the most widely used stainless steel in the world. The lower carbon
version, Type 304L (S30403) is always preferred in more corrosive environments where
welding is involved. Molybdenum (Mo) is added to some stainless steels to increase their
corrosion resistance, particularly in marine and acidic environments. It increases an
alloy's pitting and crevice corrosion resistance. These corrosion forms are caused by the
common and highly aggressive chloride ion (Cl¯), which is present in salts, such as sea
salt and table salt. When 2-3% molybdenum is added to Type 304 or 304L, we create
Type 316 (S31600) or 316L (S31603) stainless steel. They are sometimes referred to as
the marine grades of stainless steel.
Basic properties:
Excellent corrosion resistance in organic acid, industrial and marine
environments.
Excellent weldability (all processes)
Excellent formability, fabricability and ductility
Excellent cleanability, and hygiene characteristics
Good high and excellent low temperature properties (high toughness at all
temperatures)
Non magnetic (if annealed)
Hardenable by cold work only (These alloys are not hardenable by heat treatment
DEPARTMENT OF CIVIL ENGINEERING 6 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
3.2 Ferritic
Ferritic stainless steel has properties similar to mild steel but with the better corrosion
resistance. These alloys are somewhat less ductile than the austenitic types. These are
plain chromium stainless steels with varying chromium content between 12 and 18%, but
with low carbon content. A commonly used grade is Type 430 (S43000)
Basic properties:
Moderate to good corrosion resistance increasing with chromium content
Not hardenable by heat treatment and always used in the annealed condition
magnetic
Weldability is poor
Formability not as good as the austenitic
3.3 Austenitic-Ferritic (Duplex)
Austenitic-Ferritic (Duplex) Duplex stainless steels have a metallurgical structure that is
a combination of both ferritic and austenitic. They have a high chromium content (from
18 to 26 percent) and a low nickel content (from 4 to 7 percent). Most grades also contain
some molybdenum (from 2 to 3 percent). A common grade is 2205. Nitrogen (N) is
added to some stainless steels, but is very important in duplex grades. It has several
beneficial effects. Like nickel, nitrogen promotes austenite (especially important for
welding) and, like molybdenum, it improves resistance to pitting and crevice corrosion. It
also increases strength. Duplex stainless steels are inherently stronger, but a grade such as
2205, which contains about 0.15% nitrogen, has over twice the yield strength of Type
316L.
Basic properties:
High resistance to stress corrosion cracking
Increased resistance to chloride ion attack
DEPARTMENT OF CIVIL ENGINEERING 7 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Higher tensile and yield strength than austenitic or ferritic steels
Good weldability and formability
3.4 Martensitic
Martensitic stainless steel contains mostly 11 to 13% chromium and is both strong and
hard with moderate corrosion resistance. Martensitic stainless steels were the first
stainless steels commercially developed (as cutlery) and have relatively high carbon
content (0.1 - 1.2%) compared to other stainless steels. Type 420 (S42000) is a typical
example
Basic properties
Moderate corrosion resistance
Can be hardened by heat treatment and therefore high strength and hardness levels
can be achieved
Poor weldability
Magnetic
GradeUNS No.
Family Crc Nic Moc Nc C(max)
Yield strength MPa (min)b
Tensile strength MPa (min)b
Elong % (min)b
430 S43000 Ferritic 17 0.12 205 450 22
420 S42000 Martensitic 130.15
min1480c 1720 8c
304 S30400 Austenitic 18 9 0.08 205 515 40
304L S30403 Austenitic 18 9 0.03 170 485 40
316 S31600 Austenitic 17 11 2.1 0.08 205 515 40
316L S31603 Austenitic 17 11 2.1 0.03 170 485 40
2205S31803
S32205Duplex 22 5 3
0.1
50.03 450 620 25
DEPARTMENT OF CIVIL ENGINEERING 8 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
b Annealed condition except for grades 420c Typical values
4 PROPERTIES OF STAINLESS STEEL
Physical and Chemical Properties of stainless steel are Presented in the Table 1
(Reference 2)
4.1 Mechanical Properties of Stainless Steel
In terms of mechanical properties, stainless steels can be roughly divided into four groups
with similar properties within each group: martensitic and ferritic-martensitic, ferritic,
ferritic-austenitic, austenitic. The difference in the mechanical properties of different
stainless steels is seen more clearly in the stress-strain curve below Fig 2 (Reference 3d)
From the graph we can say that,
For austenitic grade as ultimate strength increases ductility also increases hence energy
absorbing capacity also increases.
But in case of martensitic as the ultimate strength increases ductility decreases at a very
gradual rate and hence the percentage elongation also decreases
DEPARTMENT OF CIVIL ENGINEERING 9 M.C.E Hassan.
Table 1.Physical and Chemical Properties Of stainless Steel
Fig 2 Stress-Strain Curve
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
IS STAINLESS STEEL COSTLY?
It is a commonly held perception that stainless steel is "costly". There is only a grain of
truth in this perception because the initial cost of stainless steel products will definitely be
higher. However to work out the cost of ownership and usage over the design life of the
structure, say 50 or 80 years, one has to include the initial cost and add the cost of
maintenance, repair, replacement, downtime and other factors. This method called as the
life cycle costing (LCC) analysis, will show how much the choice of different materials is
actually going to affect the cost of ownership and use of the structure. Viewed in this
manner stainless steel always proves itself to be the most cost-effective choice over the
design life of the structure or the product. The application could be a kitchen utensil, a
railway coach, a handrail or an RCC structure. The end result is always the same stainless
steel is cost-effective to the user.
5. LIFE COST ANALYSIS OF STAINLESS STEEL
DEPARTMENT OF CIVIL ENGINEERING 10 M.C.E Hassan.
UNEXPECTED COSTADDITIONAL OPERATING COSTREPLACEMENT COSTLOST PRODUCTION COSTMAINTANANCE COSTINSTALATION COSYMATERIAL COST
INSTALATION COSY MATERIAL COST
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
STAINLESS STEEL CARBON STEEL
In developed countries, bridges, which were built about 50 years ago, are crumbling.
Expensive repairs, which cost much more than the original cost of the project itself, are
imposed on hapless governments, which have no other choice. Repairs also lead to large-
scale disruption of traffic, the economy and the lives of the commuting public. Because
of these reasons, they are now specifying stainless steel reinforcement bars for concrete
for such mega projects. (Reference 3b)
Take for instance the repair cost of Old Thane Creek Bridge. A-5 year life extension after
just 10 years of service cost eight times the original cost (800% increase) Partial repair to
Janak Sethu built in 1981 in Delhi cost Rs 32 crore in 1999, whereas the initial cost of the
bridge was only Rs. 9 crore (250% increase).
All of us witness the amount of distress in concrete in infrastructural projects in India.
And at a time when infrastructure is being expanded in our country, introduction of
stainless steel reinforcement bars for concrete may prove to be an ideal solution. We can
also avoid the mistakes committed by the developed countries.
The increase in overall cost of the project by the introduction of stainless steel
reinforcement bars can vary from 0.5% to 15% depending on the design. But given the
huge amount of savings in repair and maintenance, we feel that this increase is nominal
and justified.
Selective substitution: Maximum durability is obtained with total substitution of
stainless steel rebar in the structure. However, recognition of the benefits of using
stainless steel rebar has greatly increased interest in its application and stimulated
research and development activity leading to selective substitution being considered as a
means of achieving enhanced durability at minimum increase in initial cost. For example,
DEPARTMENT OF CIVIL ENGINEERING 11 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
enhanced durability can be achieved by substituting stainless steel for carbon steel rebar
in the parts of the bridge considered to be at high risk to corrosion while the remainder of
the reinforcement will be normal carbon steel. (Schaffhausen Bridge - Only half percent
increase in initial project cost).
The situation with the bridges in Sweden is given in the Fig 4. On an average, most
bridges need a repair between 18-22 years, at an average cost of the original cost of the
bridge itself. If selective use of stainless steel rebar were to be made in the initial stages,
there would have been tremendous savings for the government concerned, and the bridge
would easily last over a hundred years -- trouble free. In the above example, the initial
capital cost increase amounts to 4% for Type 304 and 8% for Type 316
To illustrate the point further, the costs associated with the UK Midlands Link
Viaduct are given:
DEPARTMENT OF CIVIL ENGINEERING 12 M.C.E Hassan.
Actual life costing Example-Oland Bridge, Sweden.
Fig 4
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Built in 1972 at a cost of £28 million, evidence of corrosion became apparent
after two years of operation.
By 1989, £45 million had been spent on repair.
By 2010 it is estimated that a further £120 million will be spent on repair.
Estimated first cost of installing stainless steel reinforcement in critical locations
-- £3.4 million (i.e. a 12% increase in the initial cost of the via duct).
The total cost of repair of the carbon steel reinforcement till the year 2010 would
be £45 plus a further £120 million = £165 million or nearly six times the original
cost of building the viaduct. For a 40-year service life of the viaduct, the price to
be paid for not using stainless steel rebar is indeed exorbitant.
Although the initial cost of stainless steel rebar is higher than carbon steel the use of
stainless steel reinforcement in the viaduct would have been an extremely cost effective
solution and an ensured trouble free life for over a century
Marine pier in Progresso, Mexico
The marine pier in Progresso, Yucatan (Mexico), was built in 1937-1941A detailed
account of the history and remarkable performance of this pier has been provided by
Torben Skovsgaard (ARMINOX) and Asger Knudsen (RAMBØLL) in the
August/September 1999 issue of Concrete Engineering International. According to this
publication, the 2.1 km long pier was constructed by a Danish contractor. Stainless
reinforcement (Type 304) was incorporated in view of the severely corrosive exposure
conditions and the relatively high porosity of the concrete.
According to the Progresso Port Authority, no major repairs or significant maintenance
activities have taken place over the lifetime of this structure. In contrast, severe
degradation has occurred on an adjacent pier built much later, in the 1960's, with carbon
DEPARTMENT OF CIVIL ENGINEERING 13 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
steel reinforcement. The photograph shows the destruction of the conventional structure
in the foreground, with the stainless steel reinforced pier in the background.
An excellent comprehensive report on the history, inspection and condition of the
Progresso pier has also recently been published by ARMINOX. This report documents
inspection work performed in December 1998 by RAMBØLL Consulting Engineers and
Planners on the initiative by ARMINOX.
6. ADVANTAGES
The following benefits of stainless rebar inherently good corrosion resistance
Corrosion resistance: Stainless steel's ability to resist corrosion has been well
established in hundreds of applications in numerous industries. When embedded in
concrete, rebar made of S31600, for example, shows superior (five to ten times better)
resistance than that of carbon steel. Stainless steel rebar has been used in several
highway overpasses and parapets in the U.K., Michigan, Oregon, New Jersey, and
Ontario; in concrete structures constructed in aggressive marine environments; and in
the repair and renovation of historic buildings.
Ease of handling and shipping: Unlike coated rebar, stainless steel is much easier
to work with during shipment and while on site. Its inherent protective oxide layer is
resistant to damage; it cannot chip, crack or fail. Stainless steel is also easily welded
and can be bent into desired shapes.
Lighter structure (greater strength): When bridge-builders make use of either
duplex stainless steel rebar or austenitic stainless steel that has been cold-worked,
several design changes are possible. For instance, a thinner concrete cover could
potentially be used on the deck of a bridge (reduced to, say, 50 millimeters), and
because its mechanical properties (specifically, yield and tensile strengths) are
superior to those of carbon steel, smaller-diameter stainless rebar can be employed.
DEPARTMENT OF CIVIL ENGINEERING 14 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Also, if carbon steel rebar is replaced with stainless steel of a similar size, the space
between the rebar latticework can be widened. Stainless is being considered in many
expansion joint designs as well.
Economical cost (life cycle cost analysis): Bridges constructed of stainless steel
rebar can be expected to last more than 100 years. So when the total cost of repairing
and maintaining carbon steel rebar in a concrete structure over this length of time is
taken into account, the higher up-front cost of stainless is justified. Stainless rebar is
so durable that new high-strength concrete mixes (containing, for example, bentonite,
plasticisers, superplasticisers or polypropylene) would likely be used in conjunction
with the stainless rebar to utilize its long-life potential. Also, to reduce costs, stainless
steel may be used only in those areas of a structure where carbon steel is judged to be
at high risk of corroding.
Fire and heat resistance: Special high chromium and nickel-alloyed grades resist
scaling and retain strength at high temperatures.
Impact resistance: The austenitic microstructure of the 300 series provides high
toughness, from elevated temperatures to far below freezing, making these steels
particularly suited to cryogenic applications
Environmentally friendly: Once their service is complete, they should be 100%
Recyclable, thereby completing the life cycle to be used once again. Stainless Steel is
such a material. The longevity of stainless is the result of the alloying composition
and, therefore, it has a natural corrosion resistance. Nothing is applied to the surface
that could add additional material to the environment. It does not need additional
systems to protect the base metal; the metal itself will last. Stainless steel products
complete their service life. There is less concern about disposal since this material is
100% recyclable. In fact, over 50% of new stainless steel comes from old remelted
stainless steel scrap, thereby completing the full life cycle.
Durability: In composite structures like RCC bridges, 125 years of trouble-free
service life can be guaranteed if stainless steel rebar is used
DEPARTMENT OF CIVIL ENGINEERING 15 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Available in many different product forms - plates, sheets, strips, bars, rods, wires,
wire products, tubes, angles, sections, fasteners, castings, extrusions etc.
Good strength
Good weldability for common rebar grades
Good ductility for common rebar grades (capable of 3D 180E bends)
No coatings to chip, crack, deteriorate
No coatings to damage and repair
Good mechanical properties for common rebar grades at high and low temperatures
7. APPLICATIONS
Possible applications for corrosion resistant stainless rebar could include
A host of marine structures such as bridge decks, sidewalks, ramps, parapets, pilings,
barriers, retaining walls, anchoring systems, parking garages, sea walls, columns,
piers, jetties and moorings
Supports for reinforced concrete (i.e., bridge decks)
Balconies and frames for front-elevation units
Anchorages and any kind of joints
Offshore platforms
Framers and anchorages for damp environments, tunnels, Underpasses and subways
Bridges, viaducts, overpasses
Cement frameworks with magnetic characteristics
Frameworks which are prone to breaking up due to frost or because of low
temperatures
Concrete slabs for drainage in environments with corrosive agents
Supports/restoration for statues, monuments, cement, stone and marble works
DEPARTMENT OF CIVIL ENGINEERING 16 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Stainless steel rebar applications in various countries is listed below
1) The marine pier in Progresso, Yucatan (Mexico), was built in 1937-1941.
2) A coastal replacement bridge under construction at North Bend, Oregon has used
2205 stainless steel rebar instead of carbon steel rebar for critical structural elements
in a harsh marine environment. Oregon Department of Transportation (ODOT),
which has chosen to use 2205 duplex stainless, expects the new bridge to provide
maintenance-free service for an amazing 120 years. That is 2.5 times the service life
of the bridge it is replacing!
3) New Haynes Inlet Slough Bridge
Completed state of the New Haynes Inlet Slough Bridge from north bank of the inlet,
with retired timber trestle bridge at right and contractor's partially dismantled work
bridge in left background.
DEPARTMENT OF CIVIL ENGINEERING 17 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
4) More than 75 tons of Type 316LN stainless rebar was used for the Brush Creek
highway bridge in Oregon (1998).
5) 165 tons of 2205 (duplex) stainless rebar were supplied for the new ramp of the
Garden State Parkway in New Jersey (1998).
6) Nuclear Plant in France: Stainless steel has been used to build ferroconcrete drums
for disposal of radioactive nuclear wastes. In this application, for safety reasons, is
mandatory the use stainless steel in order to avoid cracks in the concrete (caused by
reinforcing bars corrosion) and subsequent waste leaking
7) Stainless steel reinforcement has been used in order to minimize future maintenance
work of the buildings. The Guildhall Yard East project in London, England (1996),
one of the most famous historic buildings in the center of the City of London utilized
DEPARTMENT OF CIVIL ENGINEERING 18 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
over 140 tons of Type 304 rebar. Although the new structures will not be exposed to de-
icing salts or a marine environment, the design engineers were looking for a very long
design life, in keeping with the famous historic buildings on the site
8) 240 tons of Type 316 stainless steel rebar used in the road slab of an underpass at
Cradlewell, UK (1995).
9) 46 tons of austenitic stainless rebar were used in a new laboratory building of the
National Physical Laboratory in Teddington, United Kingdom. The austenitic grade
reportedly used was 316S33 ribbed bar, in accordance with BS 6744. Sizes ranged from 8
to 40 mm diameter, with a dominant size range of 10 to 12 mm diameter.
DEPARTMENT OF CIVIL ENGINEERING 19 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
Stainless steel is also used in restoration works
10) Colosseo, Roma - Italy
The work involved the partial restoration of the arena floor. The foundations in roman
concrete were reinforced by stainless steel ribbed bars type AISI 304L in diameters 6, 8,
10, and 14 mm. The Archeological Superintendence of Rome supervised the works.
11) Rocco Church, Dolo, Venezia - Italy
The work of restoration was realized employing stainless steel as the wall tie for the
supporting structure.
12) San Benedetto Po bridge, Mantova - Road 43, Romana, Anas Milano Italy
Maintenance work in the foundation decks and piers of the reinforced concrete bridge.
The Stainless steel reinforcing was joined with existing mild steel reinforcing.
DEPARTMENT OF CIVIL ENGINEERING 20 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
13) Glandstone Bridge, Queenslans, Australia
The Gladstone Bridge was built in 1960 and showed corrosion of the reinforcing mild steel
on the deck. The maintenance works have seen the use of 12 mm diameter stainless steel
ribbed bars type 316L joined with the original carbon steel
14) Stainless steel rebars were used in a Sea-front building restoration in Scarborough,
UK (early 1980's). They were selected for stabilization of the sea wall, in-situ concrete
on the promenade, and pre-cast units around the main entrance. Type 316 stainless steel
DEPARTMENT OF CIVIL ENGINEERING 21 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
rebar was utilized immediately adjacent to the sea, while Type 304 stainless reinforcing
was applied further inshore. Conventional rebar was used well back from the sea front.
8. CONCLUSIONS
The primary intention of this paper is to create awareness on the substantial advantage
one can get by using stainless steel as reinforcement in concrete structures.
The following are the conclusions drawn from the study,
Despite the initial cost, there is considerable potential in savings of life cycle cost,
especially infrastructures, which are exposed to corrosive environment.
Best suited material at all temperatures. Also stainless steel are suited for
cryogenic applications.
Available in different grades and hence significant savings can be done.
Also the material is available in different forms, which is more advantageous.
Material is new generation and environmental friendly hence can be very rightly
utilized as a new generation material for all applications.
DEPARTMENT OF CIVIL ENGINEERING 22 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
9. REFERENCES
1. K Mani and P Srinivasan-“Service life of RC structures in Corrosive Environment: A comparison of carbon steel And Stainless steel Bars”- Indian Concrete Journal, Volume 75,1-12,2001.
2. Y Sakumoto, T Nakazato and A Matsuzaki- “Properties of Stainless Steel For Building Structures”- ASCE Journal Of Structural Engineering, Volume 122,1-6,199
3. Web Site References:
a. Use of Stainless Steel Reinforcement Bars for Concrete Structures-By Dr. N.C Mathur (President), Ramesh R Gopal (General Manager), Nickel Development Institute & Secretary Indian Stainless Steel Development Association, 55-A, Uday Park (ff) Khel Gaon Marg, New Delhi - 49(Published in New Building Materials & Construction World - September 2000)
DEPARTMENT OF CIVIL ENGINEERING 23 M.C.E Hassan.
NEW GENARATION STAINLESS STEEL REINFORCEMENT BAR FOR CONCRETE STRUCTURE
b. www.ISSDA.com-Stainless Steel Assures Durability And Enhances Aesthetics Of Structures-By Ramesh R Gopal, Secretary, ISSDA and General Manager of NiDi.
c. www.SSINA.com- Stainless Steel Bridge-New Bridge Uses Stainless Steel Rebar To Last 120 Years, CNC West Feature Article, August • September 2002 • Vol. XX No. 6 • An Arnold Publication
d. www.Outokumpu.com
e. www.sustainable-development.gov.uk
f.www.Key-to-Steel.com
DEPARTMENT OF CIVIL ENGINEERING 24 M.C.E Hassan.