Sustainability of SteelSustainability of Steel Structures...Sustainability of Steel Structures Helena Gervásio | 6 MAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL

Sustainability of SteelSustainability of Steel Structures

Helena Gervásio(hger@dec uc pt)([email protected])

Aalesund, 18th September 2008

2|Sustainability of Steel Structures Helena Gervásio

TABLE OF CONTENTS

Introduction to Sustainable Construction

Contribution of steel to Sustainable ConstructionContribution of steel to Sustainable Construction

Tools for Sustainable Assessment

Case study: Life cycle assessment of a residential house

Institute for Sustainability and Innovation in Structural Engineering


MAIN FACTORS AFFECTING THE SUSTAINABILITY OFMAIN FACTORS AFFECTING THE SUSTAINABILITY OF

Construction is the largest industrial sector in Europe (10-11% of GDP) and

MAIN FACTORS AFFECTING THE SUSTAINABILITY OF MAIN FACTORS AFFECTING THE SUSTAINABILITY OF THE CONSTRUCTION SECTORTHE CONSTRUCTION SECTOR

Construction is the largest industrial sector in Europe (10-11% of GDP) andin the United States (12%); in developing world it represents 2-3% of GDP

Construction sector provides 7% of world employment (28% of industrialemployment)

Construction sector consumes 50% of all resources taken from earth

Building and construction sector consumes 25-40% of all energy used(OECD countries)

The built environment is the largest source of GHGs in Europe and itaccounts for ≈ 40% of world GHG emissions

Construction and demolition waste accounts for 30-50% of total wasteConstruction and demolition waste accounts for 30-50% of total wastegenerated in higher income countries

Source: UNEP Industry and Environment (2003)



MAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRYIndustrial direct COIndustrial direct CO2 2 emissions (2004)emissions (2004)

Iron and steelOtherIron & steel industry accounts for

27%28%27% of direct CO2 emissions from

the industry sector

3 4% f G GChemicals &

petrochemicals16%

≈ 3-4% of global GHG emissions

(IPCC)

1 7 t f CO i itt d f Non-metallic minerals

27%

1.7 tonnes of CO2 is emitted for every

tonne of steel produced

Non-ferrous metals

2%Source: “Tracking Industrial Energy Efficiency and CO2 Emissions “(IEA, 2007)



MAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRY

Industrial final energy use (2004)Industrial final energy use (2004)Industrial final energy use (2004)Industrial final energy use (2004)

1%Chemicals & petrochemicals

Iron and steel

30%2%1%1%

16%Non-metallic minerals

Paper, pulp and print

Food and tobacco

4%

4%

2% Non-ferrous metals

Machinery

Textile and leather

Mining and quarrying

19%6%

5%

Mining and quarrying

Construction

Wood

Transport equipment

9% Non-specified

Source: “Tracking Industrial Energy Efficiency and CO2 Emissions “(IEA, 2007)



MAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL INDUSTRY

⇒⇒Use of outdated technologies and low quality resourcesUse of outdated technologies and low quality resources

⇒⇒Worldwide variability in energy intensities and COWorldwide variability in energy intensities and CO22emissions emissions

Recycling BAT and higher efficiency of energyRecycling BAT and higher efficiency of energyRecycling, BAT and higher efficiency of energy Recycling, BAT and higher efficiency of energy

⇒⇒ Energy efficiency Energy efficiency ⇒⇒ Saving potential in primary energy Saving potential in primary energy about 2.3 about 2.3 –– 2.9 EJ/year2.9 EJ/year

⇒⇒ Complete recovery of used steelComplete recovery of used steel ⇒⇒ Raise the potential to about 5Raise the potential to about 5⇒⇒ Complete recovery of used steel Complete recovery of used steel ⇒⇒ Raise the potential to about 5Raise the potential to about 5EJ/year EJ/year

⇒⇒ Reduction of COReduction of CO22 emissions emissions –– 220 220 –– 360 Mt CO360 Mt CO22/year/year


Source: “Tracking Industrial Energy Efficiency and CO2 Emissions “(IEA, 2007)


“Sustainable Development meets the needs of the

SUSTAINABLE DEVELOPMENTSUSTAINABLE DEVELOPMENTSustainable Development meets the needs of the

present without compromising the ability of futuregenerations to meet their own needs” In Bruntland report

SUSTAINABLE CONSTRUCTIONSUSTAINABLE CONSTRUCTION

In Bruntland report

Sustainable Construction results from the application ofthe principles of Sustainable Development to the globalcycle of construction, from raw material acquisition,through planning, design, construction and operation, tofi l d liti d t tfinal demolition and waste management.

Chrisna du Plessis – Agenda 21 for Sustainable Construction inDeveloping Countries



CONTRIBUTION OF STEEL AND STEELCONTRIBUTION OF STEEL AND STEELCONTRIBUTION OF STEEL AND STEEL CONTRIBUTION OF STEEL AND STEEL STRUCTURES TO STRUCTURES TO SUSTAINABILITY SUSTAINABILITY



LIFE CYCLE OF STEELLIFE CYCLE OF STEEL

Steelmaking

ConstructionEnd-of-life

St l t tSteel structures



STEELMAKING PROCESSSTEELMAKING PROCESSELECTRIC ARC FURNACEBLAST FURNACE

e.g. Production of 1 kg of steel (sections) (IISI)Total primaryEnergy: 28.97 MJ 9.50 MJ

CO2 emissions: 2 45 kg 0 44 kg

World production of steel (IISI, 2006)

Oxygen – 65.5 %; Electric – 32.0 %; Open hearth – 2.5%

CO2 emissions: 2.45 kg 0.44 kg


yg ; ; p


STEELMAKING PROCESSSTEELMAKING PROCESSSustainable countermeasuresSustainable countermeasures

Energy efficiencyHighly energy efficient facilities (e.g. high efficiency combustion burners,optimization of the reheating of furnaces, etc)

Recycling of products (e.g. waste plastic, waste tires, etc)

PJ/year Integrated steelworks energy intensity (GJ/tonne steel)

NIPPON STEEL CORUS

Recycling of products (e.g. waste plastic, waste tires, etc)

Institute for Sustainability and Innovation in Structural EngineeringSource: Nippon Steel – “Sustainability Report 2007” Source: Corus Corporate Responsability Report 2007/08


STEELMAKING PROCESSSTEELMAKING PROCESSSustainable countermeasuresSustainable countermeasuresReduction of CO2 emissions2

CO2 Million tonnes/year Direct and indirect CO2 emissions from integrated l ki (k )/ li id l

NIPPON STEEL CORUS

steelmaking (kg)/tonne liquid steel

2012 reduction 2012 reduction target (<1.7 t/tls)target (<1.7 t/tls)

2020 reduction 2020 reduction target (<1.5 t/tls)target (<1.5 t/tls)

Source: Nippon Steel – “Sustainability Report 2007” Source: Corus Corporate Responsability Report 2007/08



STEELMAKING PROCESSSTEELMAKING PROCESSSustainable countermeasuresSustainable countermeasuresBy-products 1 tonne of iron generates 600 kg of by-

d t ( l d t d l d )By products

Reutilization of by-product gases (e.g use of coke oven gas and blast furnace gas as fuel gas for heating furnaces or energy sources for power generation plants, etc)

products (slag, dust and sludge)

Use of by-products as raw materials in the steel works or in other industries (e.g. cement production) The use of blast furnace and steel slag as a substitute for

clinker in cement production could contribute 140 – 185 Mt pCO2 reduction (source: IISI)

Example: NIPPON STEEL

InIn-company

use (30%)By-products

Power plant (40%)

By-product gases

Cement industries and others

(68%)Waste (2%)

Fuel gas (60%)


( )(2%) (60%)

Source: Nippon Steel – “Sustainability Report 2007”


STEELMAKING PROCESSSTEELMAKING PROCESSSustainable countermeasuresSustainable countermeasures

Improved research and new technologiesImproved research and new technologies

Research and development (R&D)As a result of systematic technological improvements the best EU steel

e.g. Ultra-Low CO2 Steelmaking (ULCOS) project (http://www.ulcos.org/en/index.php)E j t i l i ll j EU t l i i i t d ti

As a result of systematic technological improvements, the best EU steel plants are operating at the limits of what is presently technically possible

European project, involving all major EU steel companies, aiming at a drasticreduction in CO2 emissions from steel production (50% reduction in comparison with todays’ best routes)

Use of High Strength Steel (HSS)

e g HISTAR® steels (ARCELORMITTAL)e.g. HISTAR® steels (ARCELORMITTAL) The use of HISTAR for common steels achieves reductions of 32% in steel columns and 19% in beams, allowing to save in CO2 emissions

(source: ArcelorMittal: Bold Future 2007 – Annual report)



CONSTRUCTIONSteel structures are installed rapidly – the time of construction

b d d t h lf th ti d d f th t f

CONSTRUCTION

can be reduced to half the time needed for other type of

construction;

Frame elements are delivered in time for installation minimizing

the area needed for storage and contributing to an efficient

construction site;

The prefabrication of frames provides a safer and cleaner

working environment;

Prefabrication ensures accurate and quality workmanship;

Waste during construction is reduced to a minimum and most

waste is recyclable.


y


STEEL STRUCTURES

Steel has a high strength-to-weight ratio making of it a very

STEEL STRUCTURES

Steel has a high strength to weight ratio making of it a very

efficient material;

Steel is 100% recyclable leading to the minimization of natural

resource depletion and environmental impacts;

Steel has a long life span allowing to amortize the

i t l i t d t it d ti tenvironmental impacts due to its production stage;

Thermal and acoustic insulation may be adapted to any localy p y

or functional requirement.



STEEL STRUCTURESSTEEL STRUCTURES

Steel frames can easily be adapted to new functional

requirements over the building life cycle;

Rehabilitation of existing buildings is easier with steel frames

and leads to the preservation of cultural and historical value;and leads to the preservation of cultural and historical value;

A steel structure has exceptional durability, with little or no

maintenance, contributing to the safeguard of natural resources.



END OF LIFEEND-OF-LIFE

Steel is 100% recyclable and it can be infinitely recycledy y ywithout loss of quality

Creating new steel from recycled steel reduces COCreating new steel from recycled steel reduces CO2emissions (in 2006, about 894 million metric tons of CO2were saved))

By improving design, the need for new steel productioncan be reduced as steel components can be reusedcan be reduced as steel components can be reused without reprocessing

In most sectors steel reycling rates are between 80 and

Source: “Steel and you – The life of steel” (IISI)

In most sectors, steel reycling rates are between 80 and100%



HOW TO MEASURE THE SUSTAINABILITYHOW TO MEASURE THE SUSTAINABILITYHOW TO MEASURE THE SUSTAINABILITY HOW TO MEASURE THE SUSTAINABILITY OF STEEL STRUCTURES ?OF STEEL STRUCTURES ?



RATING SYSTEMSe.g. LEED - voluntary labelling system aiming to assess the global environmental performance of a building through its life cycle

RATING SYSTEMS

Process based in a system of 64 credits divided by 5 areas of environmental impacts:

. Sustainable Sites (SS)

. Water Efficiency (WE)

. Energy and Atmosphere (EA)M t i l d R (MR). Materials and Resources (MR)

. Indoor Environmental Quality (IEQ)

. Innovation and Design Process (ID)

> 26 credits Classification:

LEED certification> 33 e < 38 credits Sil> 33 e < 38 credits Silver > 39 e < 51 credits Gold> 52 e < 69 credits Platinum



RATING SYSTEMSAssessment of steel structures according to LEED system

RATING SYSTEMS

Materials and Resources (MR)Building reuse – steel buildings are flexible and adaptable

Construction waste management – steel is consistently recycled

Resource reuse – structural steel can be refabricated and reused

Recycled content – steel has close to 100% recycled content from scrap

Innovation and Design Process (ID)Use of composite members

Design for deconstruction

Design for adaptability



LIFE CYCLE ANALYSISThe environmental impacts of buildings occur throughout alllife cycle stages of a building or other construction;

LIFE CYCLE ANALYSIS

life cycle stages of a building or other construction;

To overcome the shifting of burdens from one life cycle stageto another when deciding between options the life cycleto another when deciding between options, the life cycleperspective needs to be taken into account

N i t ti l t d d f t i bilit t fNew international standards for sustainability assessment ofbuildings under development follow a life cycle approach

e.g.: prEN 15643-1 Sustainability of construction works - Integrated assessment of building performance - Part 1: General framework. ISO/TS 21931-1 Sustainability in building construction - Framework for

th d f t f i t l f f t timethods of assessment for environmental performance of construction works - Part 1: Buildings.



LIFE CYCLE ANALYSISLIFE CYCLE ANALYSISSystem BoundarySystem Boundary

LIFE CYCLE ANALYSISLIFE CYCLE ANALYSIS

Construction Operation End of lifeMaterial ProductionProduction

Raw Materials

EnergyAir Emissions

Raw Materials

Unit Process

EnergyWater

Water EffluentsReleases to LandOther releases

Intermediate Material or Final Product



CASE STUDYCASE STUDY



SINGLE FAMILY DWELLINGSINGLE FAMILY DWELLING



Comparative analysis between two alternative structural

INTRODUCTION

solutions of a dwelling in the context of sustainableconstruction;

Both solutions were designed for a service life of 50 yearsaccording to their respective Structural Eurocodes;

Lif l i t l l i t k i t t th b lLife cycle environmental analysis takes into account the balancebetween the operational energy and the embodied energy of thebuilding;

A sustainability analysis is carried out in order to evaluate which structural system has a better environmental performance,

id i lif l hconsidering a life cycle approach.



LIFE CYCLE ANALYSISLIFE CYCLE ANALYSISLIFE CYCLE ANALYSISLIFE CYCLE ANALYSIS

Production of materials

TransportRecycling

ConstructionTransport

Operational energyUseDemolition

Embodied energy

Operational energyUseDemolition



PROJECT OVERVIEW



APPROACH

The functional unitA residential house, for a family of 5 persons,designed to fulfil the requirements of nationalregulations about safety, comfort and energydemand for a service life of 50 yearsdemand, for a service life of 50 years



CASE STUDY1st Floor – 183 m2 2nd Floor – 183 m2 3rd Floor – 68 m2



Case ACase A Lightweight steel solutionLightweight steel solution

EXTERIOR WALL AND SLABCase A Case A –– Lightweight steel solutionLightweight steel solution

1. C 150 profile (walls), C 250 profile (slabs)2. Gypsum plaster board BA153. Rock wool (140mm)4. OSB 11 (walls), OSB 18 (slabs)( ), ( )5. Exterior Insulation and Finish System (EIFS)




INTERIOR WALLS

Case A Case A –– Lightweight steel solutionLightweight steel solution

1. C90 profile 2. Gypsum plaster board BA15 3. Rock wool (70mm) 4. Gypsum plaster board WA13 5. Ceramic




Bill of materialsMaterial Quantities Unit

Case A Case A –– Lightweight steel solutionLightweight steel solution

Material Quantities UnitConcrete 70680 kgCold formed steel 19494 kgRock wool 12335 kgGypsum plaster board 13208 kgOriented strand board 7016 kgReinforcement steel 1307 kgExterior Insulation and Finish System (EIFS): Insulation board (Polystyrene) 330 m2

Finish Coat (acrylic) 330 m2

Thermal transmittance (W/m2.oC)Element U

Exterior wall 0.240

Roof 0.292

Terrace 0.289



Case BCase B Concrete solutionConcrete solution

EXTERIOR WALL AND SLAB

Case B Case B –– Concrete solutionConcrete solution

1. Internal clay brick wall (11 cm)2. External clay brick wall (15 cm)2. External clay brick wall (15 cm)3. Mortar (2 cm) + Paint4. Air space (6 cm)5. Mineral wool (6 cm)




INTERIOR WALL


1. Concrete frame2. Clay brick wall (11cm)3 Mortar3. Mortar4. Mineral Wool (6cm)5. Stucco6. Paint7. Nesting mortar




Bill of materials


Material Quantities UnitConcrete C25/30 517482 kgReinforcement steel 15877 kgBrick walls (int. + ext.) 120852 kgBrick walls (int. ext.) 120852 kgCement mortar 38508 kgInsulation board (polystyrene) 1327 kgAlkyd paint 139 kg

Thermal transmittance (W/m2.oC)Element U

Exterior wall 0.483

Roof 0.610

Terrace 0.500



INVENTORY ANALYSIS

PRODUCTION OF CONCRETE PRODUCTION OF CONCRETE (PCA)(PCA)Portland (PCA)(PCA)Cement

Production

Fine Aggregate Production

Material Transportation

Ready-Mix Plant Operations

Coarse Functional Unit of Coarse Aggregate Production

Functional Unit of Concrete



PRODUCTION OF STEEL (IISI)PRODUCTION OF STEEL (IISI)

INVENTORY ANALYSIS( )( )

System

Raw material and energy

d ti Site boundariesproduction (including

extraction) Transportation Steelworks

Natural reso rces

Site boundariesSteel products

Non allocated

Emissions By-products

minus

Consumables production

Recovery processes

resources from earth

By-products

to earthminus

Merchant scrap,

Save external

operations

Scrap

Equivalent By-product functions

p,other

steelwork, etc

p



OPERATION STAGEOPERATION STAGEOperational energy quantificationEuropean Directive on the Energy Performance of Buildings [2002/91/CE]

OPERATION STAGEOPERATION STAGE

ISO 13790A fully prescribed monthly quasi-steady state calculation method;A fully prescribed simple hourly dynamic calculation method;Calculation procedures for detailed dynamic simulation methods.y

RCCTE (Dec.Lei 80) - Quasi-steady approach, in which dynamiceffects are taking into account by means of a gain and/or losseffects are taking into account by means of a gain and/or lossutilization factor

annual energy need for heating (Nic) < Ni annual energy need for cooling (Nvc) < Nannual energy need for cooling (Nvc) < Nv

ENERGY CERTIFICATION OF BUILDINGS



Climate data of PortugalClimate data of PortugalWinter climatic zones Summer climatic zones

Coimbra Coimbra



OPERATION STAGEOPERATION STAGEOperational energy quantification

Heating season


Heating seasonSet point temperature: 20oC

C i b li ti i t ICoimbra: climatic winter zone I1Length of heating season: 6 months

Degree-days: 1 460 oC.days

Cooling seasonCooling seasonSet point temperature: 25oC

Coimbra: climatic summer zone V2Coimbra: climatic summer zone V2

Length of cooling season: 4 months (June-September)



Operational energy quantificationEnergy need for space heating (per year):Energy need for space heating (per year):

Case A – LW. steel frame:

Operational energy quantification

NiC = 27.92 kWh/m2 (= 8835.67 kWh) < Ni = 81.08 kWh/m2

Note: From the simulation analysis Ni = 4216.60 kWh (-52%)

NiC = 34.17 kWh/m2 (= 10813.32 kWh) < Ni = 81.08 kWh/m2

Case B – Concrete frame:

y i ( )

iC ( ) i

Case A – LW. steel frame:Energy need for space cooling (per year):Energy need for space cooling (per year):

Nvc = 13.98 kWh/m2 (= 4424.50 kWh) < Nv = 18.00 kWh/m2

Note: From the simulation analysis Nv = 6517.08 kWh (+47%)

Nvc = 11.26 kWh/m2 (= 3563.82 kWh) < Nv = 18.00 kWh/m2

Case B – Concrete frame:

y v ( )


vc ( ) v



OPERATIONAL ENERGY vs. EMBODIED ENERGY




ENDEND OFOF LIFE STAGELIFE STAGE

END-OF-LIFE SCENARIOS

ENDEND--OFOF--LIFE STAGELIFE STAGE



ENDEND OFOF LIFE STAGELIFE STAGE

ALLOCATION OF SCRAPALLOCATION OF SCRAP Closed material loop recycling Closed material loop recycling

ENDEND--OFOF--LIFE STAGELIFE STAGE

OC O O SCOC O O SC C osed ate a oop ecyc gC osed ate a oop ecyc gmethodology (IISI)methodology (IISI)

S (kg)S (kg) Net scrap = RR - S

Steel product (1kg)

LCI credit/debit = (RR – S) x Y (Xpr – Xre)

RR (kg)

LCI product = X’ – [(RR – S) x Y (Xpr – Xre)]

RR (kg)



RESULTS OF LIFE CYCLE ANALYSIS



RESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISLIFE CYCLE ENVIRONMENTAL ANALYSIS – LIGHTWEIGHT

STEEL FRAME



RESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISLIFE CYCLE ENVIRONMENTAL ANALYSIS – CONCRETE FRAME



RESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISLIFE CYCLE ENVIRONMENTAL ANALYSIS



RESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISRESULTS OF LIFE CYCLE ANALYSISLIFE CYCLE ENVIRONMENTAL ANALYSIS



FINAL REMARKSFINAL REMARKSFINAL REMARKSFINAL REMARKS

Steel structures have a positive contribution towards the

sustainability of the construction sector;

Steel industry needs to be recognize by the role played in the

sector;

It is necessary to demonstrate the benefits of steel structures

based in credible data and appropriate methodologies;

Life cycle analysis allow to highlight the advantages of steel

structures, namely, recycling and reuse of structures;

Further initiatives leading to more eficient life cycle performance of

steel structures (e.g. deconstruction, modular construction, design

for adaptability, improvements in the energy efficient, etc).


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Sustainability of SteelSustainability of Steel Structures...Sustainability of Steel Structures Helena Gervásio | 6 MAIN FACTORS AFFECTING STEEL INDUSTRYMAIN FACTORS AFFECTING STEEL