High Strength Steel Reinforcement – A New Beginning in Smart ...

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High Strength Steel Reinforcement – A

new beginning in Smart Construction

N. Saravanan

Synopsis

About NatSteel

High Strength Steel Reinforcement (HSR)

Benefits

Trial Designs

HSR Adoption in Other Countries

HSR Adoption in Singapore

Synopsis

About NatSteel


Benefits

Trial Designs



NatSteel is a fully integrated steel mill providing steel reinforcement

solutions in Asia

Mesh Solutions

Prefabricated Cage Solutions

Carpet Reinforcement Solutions

Cut & Bend and Coupler Products

Synopsis

About NatSteel


Benefits

Trial Designs



High Strength Steel Reinforcement (HSR): Grade 600

• High Strength Steel – Grade 600B

Yield Strength: ≥ 600MPa

Tensile / Yield – Ratio : ≥ 1.08

Agt : ≥ 5%

6

Design Stress – Strain diagram for Grade 600 steel


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Use of Grade 600 steel is permitted under Singapore National

Annex to Eurocode 2 (Clause: 3.2.2 (3))

Design governed by EC2 (SS EN 1992-1-1)


Normal strength concrete can be used with HSR

Pure Compression members: It’s beneficial to use HSR with High

Strength Concrete

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Synopsis

About NatSteel


Benefits

Trial Designs



Grade 600 Steel – A Potential Productivity Driver

Steel reinforcement forms the basis of any reinforced

concrete building and Singapore uses about 1.7Million

tonnes / year

Grade 600 steel can be used in all sectors of construction

such as, Residential, Commercial, Industrial, Infrastructure &

Institutional projects

Use of Grade 600 steel is expected to bring higher

construction productivity in the many aspects of construction,

as detailed in the following slides

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Benefits of using Grade 600 Steel…

11 *Values in the tables are estimated values

Item Description

Steel Savings Potential to reduce steel reinforcement – up to 20% to 30%

compared to current grade 460 steel

Concrete Savings Reduction in structural element size is possible when used

with appropriate grade of concrete and results in overall

dead load being reduced

Steel fabrication About 20% less workers are needed

Logistics Less trucks carrying steel reinforcement on the roads –

about 20% less

Site Crane Handles about 20% less steel and frees up crane time for

other construction activities thereby speeding up constr.

Manpower - Steel

fixing / Installation

About 20% less onsite workers are required to install / fix

steel reinforcement onsite

Lighter foundations Due to reduction in member size resulting in lighter super

structure, foundation loads can be reduced

Benefits of using Grade 600 Steel…

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Item Description

Less formwork Possible to reduce formwork needed for Columns and

Beams due to member size reduction

More usable space More floor space is usable due to column size reduction

Improved Safety Site safety will be improved due to less material handling,

fixing etc

Storage space Space required for site storage of steel reinforcement can

be reduced by about 20%

Time reduction Overall time savings can be accomplished by factoring in

the above items

Cost reduction Overall cost reduction can be achieved from reduced

Material, Manpower, Construction Time etc

Others Reduced – Construction noise, Fuel consumption etc

*Values in the tables are estimated values

Synopsis

About NatSteel


Benefits

Trial Designs



Case Study-1: Typical HDB Unit

14 Typical 4Room Unit

Case Study-1: Typical HDB Unit

• EC2, Steel - Gr.600, Concrete – Gr.40

• 20 Storey high

• Typical 4Room Unit

• Slab : 125mm thk

• Beam : 250 x 500mm

• Column: 300 x 1500mm

• Possible Steel Savings*:

15

Element % Savings Vs Gr.500 % Savings Vs Gr.460

Slab 19.9% 30.4%

Beam 10% (W/Nominal links) 15% (W/Nominal links)

Column# 10% (W/Nominal links) 15% (W/Nominal links)

Overall Average Savings / Unit: 13.96% 21.16%

* Approximate Design and Estimation *Distribution of Steel: Slab (40%), Beam (30%), Column (30%)

#Potential for savings

Case Study-2: NTU Learning Hub

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Case Study-2: NTU Learning Hub

Element % Steel Savings

Column 12%

Flat Slab 26%

Overall Average Savings = 20.4%

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• EC2, Steel - Gr.600, Concrete – Gr.40 (Cube)

• 8 Storey high

• Flat Slab : 300mm thk

• Column: 400 to 600mm dia.

• Possible Steel Savings*:

*Distribution of Steel: Slab (60%), Column (40%)

Synopsis

About NatSteel


Benefits

Trial Designs




The following countries have adopted Grade 600 or higher strength

steel,

Austria

Japan

South Korea

USA

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HSR Adoption in Other Countries - Austria

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Austrian Reinforcing Steel Standard B 4707:2010 for use with

Eurocode 2

HSR Adoption in Other Countries - Japan

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Japan is using Grade 600 for over a decade for Residential,

Commercial projects etc

In South Korea, Grade 600 rebar is being used for over 4 years in the construction of high-rise

buildings and is mainly driven by Korea Land and Housing Corporation (LH) due to the High

Strength, Productivity and Green benefits.

Project References from South Korea:

Public Housing Project

• Kyungnam/Kimchun Condominium (Around 1,500 Units)

• Osan Sekyo Condominium (Around 500 Units)

• JoenJu Condominium (Around 700 Units)

• Wonju Hyucksin Condominium (Atound 1,200 Units)

Private Project

• R&D Center (CHA Hospital)

• The Federation of Korean Industries Center

• DAISO Distribution center

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HSR Adoption in Other Countries – South Korea

HSR Adoption in Other Countries - USA

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690 and higher strength reinforcement steel are being used in USA for

over 8 years

Specification ASTM A 1035/A 1035M - 11

Description Deformed and Plain, Low-carbon,

Chromium, Steel Bars for Concrete

reinforcement

Yield Strength 690 MPa and 830 MPa

The Escala Condo, 31Sty + 8B, Seattle

Synopsis

About NatSteel


Benefits

Trial Designs




Current Singapore Product Standard SS560 : 2010 does not

incorporate Grade 600 steel

NatSteel initiated a NWI with SPRING to formulate the Grade 600

Product standard in Apr 2013

SPRING formed a Task Force (TF) to gather information on Grade 600

and the TF submitted it’s report to TC (Technical Committee) in June

2014

A WG (Work Group) was formed under TC to draft the Grade 600

Product Standard in Nov 2014

Currently the WG is drafting the SS560 : 2015 incorporating Grade 600

The SS560 : 2015 is expected to be published this year!

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Thank you

High Strength Steel Reinforcement – A New Beginning in Smart ...

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