Canada Research Chair in Sustainable ConstructionCanada Research Chair in Sustainable Construction

Sustainable Sustainable ConcreteConcrete Construction in the 21Construction in the 21stst

Century: Century: Challenges & OpportunitiesChallenges & Opportunities

Dr. Mohamed Lachemi, P.Eng.Dr. Mohamed Lachemi, P.Eng.

Department of Civil EngineeringDepartment of Civil Engineering

Ryerson UniversityRyerson University

OutlineOutline

• IntroductionIntroduction

• Current SituationCurrent Situation

• ChallengesChallenges

• OpportunitiesOpportunities

• Research ActivitiesResearch Activities

Canada Research Chair in Sustainable ConstructionCanada Research Chair in Sustainable Construction

Construction Industry TodayConstruction Industry Today

In Canada, the construction industry In Canada, the construction industry

generates annually $110 billions and generates annually $110 billions and

creates almost 1 million jobs. creates almost 1 million jobs.

Worldwide, this sector generates Worldwide, this sector generates

around US$3.5 trillion. around US$3.5 trillion.

Construction Industry TodayConstruction Industry Today

Issues facing the industry:Issues facing the industry:

• Little emphasis on R&D;Little emphasis on R&D;

• Poor image;Poor image;

• Mobile workforce;Mobile workforce;

• Poor productivity.Poor productivity.

United Nations World Commission on Environment and DevelopmentUnited Nations World Commission on Environment and Development

What is Sustainable Development?What is Sustainable Development?

"Sustainable development meets the "Sustainable development meets the

needs of the present without needs of the present without

compromising the ability of future compromising the ability of future

generations to meet their own generations to meet their own

needs."needs."

Sustainability & ConstructionSustainability & Construction

Sustainable development in Sustainable development in construction should translate into:construction should translate into:

Improved quality of life;Improved quality of life;Protection of the environment;Protection of the environment;Energy conservation;Energy conservation;Waste reduction & recycling;Waste reduction & recycling;Efficient use of natural resources;Efficient use of natural resources;Better operational performance.Better operational performance.

Concrete in our livesConcrete in our lives

Concrete is the most widely used Concrete is the most widely used

construction material in the world.construction material in the world.

Worldwide, the yearly production of Worldwide, the yearly production of

concrete is of the order of 13 billion concrete is of the order of 13 billion

tonnes.tonnes.

Humankind consumes only water in larger Humankind consumes only water in larger

quantities.quantities.

Concrete in our livesConcrete in our lives

Concrete Concrete ((concretusconcretus) ) is the key is the key material for material for Mankind to Mankind to create the create the built built environmentenvironment

Concrete in our livesConcrete in our lives

What would What would

modern modern

civilization civilization

be without be without

concrete?concrete?

What is Concrete?What is Concrete?

ConcretConcretee

CementCement

(Additives(Additives))

WaterWater

AggregateAggregate

Properties of ConcreteProperties of Concrete

Concrete is relatively inexpensive, Concrete is relatively inexpensive,

strong, versatile, and resistant to strong, versatile, and resistant to

fire, impact, water, and weather. fire, impact, water, and weather.

It has also a longer service life than It has also a longer service life than

most construction products and most construction products and

requires little maintenance.requires little maintenance.

How Good is Good Enough?How Good is Good Enough?

Concrete Concrete

can be can be

made to made to

last as last as

long as long as

we want it we want it

to.to.

How Good is Good Enough?How Good is Good Enough?

Concrete Concrete

can be can be

made to made to

last as last as

long as long as

we want it we want it

to.to.

How Good is Good Enough?How Good is Good Enough?

Concrete Concrete

can be can be

made to made to

last as last as

long as long as

we want it we want it

to.to.

How Good is Good Enough?How Good is Good Enough?

Why do Why do Modern Modern reinforced reinforced concrete concrete structures structures begin to begin to deteriorate deteriorate in 20 years in 20 years or less?or less?

The ProblemThe Problem

Because we use so much concrete, Because we use so much concrete,

and because concrete has and because concrete has

competing materials for many competing materials for many

applications, the tendency is to applications, the tendency is to

provide the concrete at the lowest provide the concrete at the lowest

possible cost. possible cost.

The Current SituationThe Current Situation

In the US, it will cost US$2 to US$3 In the US, it will cost US$2 to US$3

trillion over the next 20 years to trillion over the next 20 years to

repair all the concrete structures repair all the concrete structures

which are now deteriorating from which are now deteriorating from

corrosion and are poorly made and corrosion and are poorly made and

maintained. maintained. National Research Council Report, 1990. National Research Council Report, 1990.

The Current SituationThe Current Situation

In Canada, it is estimated that the In Canada, it is estimated that the

cost of repair all concrete cost of repair all concrete

structures is in the range of $75 structures is in the range of $75

billion. billion.

New PerspectivesNew Perspectives

High-performanceHigh-performance and and durabilitydurability should should

be given high priority in the selection of be given high priority in the selection of

materials and construction practices. materials and construction practices.

High Performance & DurabilityHigh Performance & Durability

The Confederation BridgeThe Confederation Bridge Expected life cycle : 100 yearsExpected life cycle : 100 years

The ice shields are exposed to salt water, The ice shields are exposed to salt water, freezing and thawing and ice abrasion. freezing and thawing and ice abrasion.

7800 t 7200 t

PEI Girder

Eiffel Tower

Is the Confederation Bridge Safe?Is the Confederation Bridge Safe?

Another ChallengeAnother Challenge

We need to learn how to better realize We need to learn how to better realize

the potential of concrete as the potential of concrete as

construction material by producing it construction material by producing it

with the use of with the use of less energyless energy and and smaller smaller

emissions of greenhouse gasesemissions of greenhouse gases. .

COCO22 Gases & Energy Consumption Gases & Energy Consumption

The production of one ton of The production of one ton of

cement releases about one ton of cement releases about one ton of

COCO22 into the atmosphere. This into the atmosphere. This

contributes to what is now contributes to what is now

commonly called commonly called global warmingglobal warming..

Cement ProductionCement Production

Natural Natural ResourcesResources

Life Cycle AnalysisLife Cycle Analysis

Water and Water and AggregatesAggregates

SCM & SCM & AdditivesAdditives

DemolitionDemolitionLandfilLandfilll

ClassifyingClassifying

Re-useRe-use

RecyclinRecyclinggLime PitLime Pit

Cement Cement ProductionProduction

Emissions Emissions & Energy& Energy

Life Life CycleCycle

Adapted from Lambros & AndrousAdapted from Lambros & Androus

Resource Resource extractioextractionn

DesignDesign

Use of Use of waste waste materialsmaterials

OpportunitiesOpportunities

The construction industry is by far The construction industry is by far

the most promising the most promising sinksink for recycling for recycling

industrial, mining, and household industrial, mining, and household

wastes because of the large volume wastes because of the large volume

of materials used and its tolerance of materials used and its tolerance

for variability in their properties. for variability in their properties.

VisionVision

This Canada Research Chair in Sustainable This Canada Research Chair in Sustainable

Construction is driven by a vision that Construction is driven by a vision that

large volumes of waste products can be large volumes of waste products can be

transformed into useful construction transformed into useful construction

materials, providing economic gains, materials, providing economic gains,

health benefits, and environmental relief.health benefits, and environmental relief.

Waste & By-product MaterialsWaste & By-product Materials

•Slag;Slag;•Fly ash;Fly ash;•Silica fume;Silica fume;•Cement kiln dust;Cement kiln dust;•Industrial sludges;Industrial sludges;•Limestone screening & quarry dust;Limestone screening & quarry dust;•Incinerator ash.Incinerator ash.

Fly Ash in the Construction IndustryFly Ash in the Construction Industry

Canada

cement, 39.9%

other, 6.7%

road construction,

0.8%mining

applications, 13.8%

concrete/grout, 38.8%

Fly Ash in the construction IndustryFly Ash in the construction Industry

U.S.A.

mining applications,

5.8%

road construction,

6.0%

structural & flowable fills,

16.5%

waste stabilization,

9.9% other, 3.5%cement raw

materials, 5.7%

concrete/grout, 52.7%

Coal-Ash Production & UtilizationCoal-Ash Production & Utilization

New Generation of ProductsNew Generation of Products

•High performance concrete (HPC);High performance concrete (HPC);

•Self consolidating concrete (SCC);Self consolidating concrete (SCC);

•Reactive powder concrete (RPC);Reactive powder concrete (RPC);

•Flowable fill;Flowable fill;

•Structural fill;Structural fill;

•Roller compacted concrete (RCC).Roller compacted concrete (RCC).

Our FocusOur Focus

Self Compacting/Consolidating Concrete Self Compacting/Consolidating Concrete

(SCC) is among the new materials that (SCC) is among the new materials that

can be used for some of our pressing can be used for some of our pressing

needs for high performance and more needs for high performance and more

durable materials, and innovative durable materials, and innovative

construction methods in the 21construction methods in the 21stst century. century.

New Generation of ConcreteNew Generation of Concrete

The problem of the durability of concrete The problem of the durability of concrete

structures due, among other things, to a structures due, among other things, to a

significant reduction in the number of significant reduction in the number of

skilled workers in Japan's construction skilled workers in Japan's construction

industry has led to the development of industry has led to the development of

SCC in the beginning of 1990s. SCC in the beginning of 1990s.

What is SCC?What is SCC?

SCC must:SCC must:– Have a fluidity that Have a fluidity that allows self-consolidation allows self-consolidation without vibration,without vibration,

– Remain homogeneous Remain homogeneous during and after the during and after the placing process, andplacing process, and

– Flow easily through Flow easily through reinforcement.reinforcement.

How to Achieve Self-Consolidation?How to Achieve Self-Consolidation?

– Limiting the coarse aggregate Limiting the coarse aggregate

content;content;

– Increasing the paste content;Increasing the paste content;

– Using a superplasticizer and Using a superplasticizer and

lowering the water-to-powder ratio lowering the water-to-powder ratio

(W/P).(W/P).Okamura and Ouchi, RILEM Symposium on SCC, Stockholm 1999Okamura and Ouchi, RILEM Symposium on SCC, Stockholm 1999

Benefits of SCCBenefits of SCC

Substantial reduction in construction Substantial reduction in construction time and labour costtime and labour cost;;

Substantial reduction in the exposure Substantial reduction in the exposure to compaction and vibration noise;to compaction and vibration noise;

Proper filling of restricted access Proper filling of restricted access areas and heavily reinforced areas and heavily reinforced members;members;

Facilitating constructibility with Facilitating constructibility with superior surface quality and finishing.superior surface quality and finishing.

Benefits of SCC (Our Approach)Benefits of SCC (Our Approach)

Optimization of cement useOptimization of cement use;;

Safe disposal of waste products;Safe disposal of waste products;

Increased life-span of structures;Increased life-span of structures;

Reduction in Greenhouse Gas Reduction in Greenhouse Gas

Emissions.Emissions.

Use of SCCUse of SCC

SCC has already been used in several SCC has already been used in several

countries. In Japan, major countries. In Japan, major

construction projects included the use construction projects included the use

of SCC in the late ’90s. Today, in of SCC in the late ’90s. Today, in

Japan, efforts are being made to free Japan, efforts are being made to free

SCC of the “special concrete” label SCC of the “special concrete” label

and integrate it into day-to-day and integrate it into day-to-day

concrete industry production. concrete industry production.

Use of SCC in JapanUse of SCC in Japan

The Akashi-Kaikyo Bridge: The Akashi-Kaikyo Bridge: the world’s longest suspension bridgethe world’s longest suspension bridge

Use of SCC in JapanUse of SCC in Japan

The use of SCC shortened the anchorage The use of SCC shortened the anchorage construction period by 20%, from 2.5 to 2 construction period by 20%, from 2.5 to 2

years.years.

Use of SCC in JapanUse of SCC in Japan

Osaka Gas Osaka Gas

Terminal: Terminal:

the the

World’s World’s

Largest PC Largest PC

LNG LNG

Storage Storage

TanksTanks

Use of SCC in JapanUse of SCC in Japan

In addition to enlarging the In addition to enlarging the

capacity of the new tanks, the use capacity of the new tanks, the use

of SCC technology resulted in:of SCC technology resulted in:

• A decrease in the number of A decrease in the number of

concrete workers from 150 to 50; concrete workers from 150 to 50;

and and

• A decrease of construction time A decrease of construction time

from 22 to 18 months. from 22 to 18 months. Osaka Gas TerminalOsaka Gas Terminal

Use of SCC in JapanUse of SCC in Japan

Osaka Gas has conducted a number of studies over Osaka Gas has conducted a number of studies over the years that eventually led to the development the years that eventually led to the development of a safe and reliable world-record capacity of a safe and reliable world-record capacity 180,000-m180,000-m33 PC LNG storage tank. In addition to the PC LNG storage tank. In addition to the advantage of the scale brought about by advantage of the scale brought about by increasing the tank capacity, construction costs increasing the tank capacity, construction costs were significantly reduced by more than 10% by were significantly reduced by more than 10% by aggressively introducing various new technologies aggressively introducing various new technologies that reduced construction cost and period. In that reduced construction cost and period. In terms of the land use, the 180,000-mterms of the land use, the 180,000-m33 PC LNG PC LNG storage tank can be installed in the same space storage tank can be installed in the same space used for a 75,000-mused for a 75,000-m33 double-walled metal tank, double-walled metal tank, which is an improvement in land use efficiency of which is an improvement in land use efficiency of 2.5 times.2.5 times. Osaka Gas Co. WebsiteOsaka Gas Co. Website

Our Research ActivitiesOur Research Activities

Structural performance models

Long-term behaviour & durability models

Sensors & NDE(actual structures)

Lab studies

Field studies

Novel concrete

mix design

Durability evaluation

Structural evaluation

Smart monitori

ng & testing

Environmental & other benefits

Material characterization

Will SCC Become the Will SCC Become the Standard for Designing Standard for Designing Concrete Structures?Concrete Structures?

““One cannot design and work One cannot design and work

with a material which one does with a material which one does

not know and understand not know and understand

thoroughly. Therefore, design thoroughly. Therefore, design

quality starts with education.”quality starts with education.”

Prof. Jorg SchlaichProf. Jorg Schlaich

Our MissionOur Mission

Our mission is to educate the future Our mission is to educate the future

leaders of the profession and to leaders of the profession and to

provide skills and foundations for provide skills and foundations for

life-long learning and growth.life-long learning and growth.

Attracting the Best and BrightestAttracting the Best and Brightest

Research Associates and PDFsResearch Associates and PDFs

Dr. K.M.A. Hossain, Dr. H. Kada (Faculty, France), Dr. H. Dr. K.M.A. Hossain, Dr. H. Kada (Faculty, France), Dr. H. Mesbah (Faculty, France), Dr. H. Farhat (Lecturer, Amer. Uni. Mesbah (Faculty, France), Dr. H. Farhat (Lecturer, Amer. Uni. Beirut) Beirut)

PhD StudentsPhD Students

R. Elimov (ExxonMobil), M. BenzerzourR. Elimov (ExxonMobil), M. Benzerzour

Masters StudentsMasters Students

B. Lambros, R. Patel, C. Anagnostopoulos, M. Ramcharitar, G. B. Lambros, R. Patel, C. Anagnostopoulos, M. Ramcharitar, G. Walters, M. Itashi, S.A. Kashif, P. MacAteer (Yolles), M. Walters, M. Itashi, S.A. Kashif, P. MacAteer (Yolles), M. Lemieux (St-Lawrence Cement)Lemieux (St-Lawrence Cement)

Undergraduate StudentsUndergraduate Students

L. Wagner, S. Sutherland, A. Hassen, W. Thaha, B. MajokL. Wagner, S. Sutherland, A. Hassen, W. Thaha, B. Majok

Team of Truly Outstanding HQPTeam of Truly Outstanding HQP

““History would have it that the chiefs History would have it that the chiefs

win the battles when, in actually, the win the battles when, in actually, the

bravesbraves do the fighting. do the fighting.””

Paraphrase of an American Indian sayingParaphrase of an American Indian saying

Why Sustainable development?Why Sustainable development?

““We do not inherit the earth We do not inherit the earth

(environment) from our parents, (environment) from our parents,

we borrow it from our children.we borrow it from our children.””

Let’s honor our debt!Let’s honor our debt!

Old African sayingOld African saying

Thank youThank you