Karen Scrivener, EPFL, Switzerland Vanderley John, USP ... · Global cement production Billion tons/year Clinker factor, global average % Global SCM volume Billion tones/year Global

Karen Scrivener, EPFL, Switzerland

Vanderley John, USP, Brazil

Ellis Gartner, Imperial College, UK

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Cement Based Materials:

cannot be replaced by alternatives

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

Cementitious

Wood

Ceramic

Iron

Lime

Asphalt

Glass

Aluminium

Copper

Materials production (Mt/year)

Cementitious materials make up ~50%

of everything we produce.

In the light of this,

CO2 emissions of 5-10%

very good

Concrete is an environmentally friendly material

Material MJ/kg kgCO2/kg

Cement 4.6 0.83

Concrete 0.95 0.13

Masonry 3.0 0.22

Wood 8.5 0.46

Wood: multilayer 15 0.81

Steel: Virgin 35 2.8

Steel: Recycled 9.5 0.43

Aluminium: virgin 218 11.46

Aluminium recycled 28.8 1.69

Glass fibre composites

100 8.1

Glass 15.7 0.85

ICE version 1.6a

Hammond G.P. and Jones C.I

2008 Proc Instn Civil Engineers

www.bath.ac.uk/mech-eng/sert/embodied/

Re

lative

en

erg

y, C

O2

Growth in cement use in last 70 years

0

2000

4000

6000

8000

0

1000

2000

3000

4000

5000

1950 1970 1990 2010

Po

pu

lati

on

(M

)

Mat

eri

als

Pro

du

ctio

n (

Mt)

Cement Crude Steel World Population

3x

34x

population

steel

cement

Cement Business as usual

CO2 Emission

Based on A blueprint for a climate friendly cement industry. WWF-Lafarge 2008

2oC - RPC 2.6 –

450ppm

Forecast growth

We need solutions for people in developing countries

0

2000

4000

6000

8000

2015 2025 2035 2045

Pro

du

ctio

n (

Mt)

OECD

China

India

Other

11 10

54

32

8

22

2637

0%

20%

40%

60%

80%

100%

2015 2050

How to meet this challenge sustainably

Solutions need to be:

◼Practical, usable by unskilled workers

◼Economically viable

Paris

18 March 2015

Beijing

18 October

2015

Sao Paulo

4,5 April

2016

UNEP SBCI Working Group on Low-CO2 Eco-efficient Cement-based Materials

Report Launched November 2016,

also as Special Issue

Cement and Concrete Research

IEA for CSI of WBCSD, 2009 road map

IEA = International Energy Agency

CSI = Cement Sustainability Initiative

WBCSD = World Business Council for

Sustainable Development

Target:

18% reduction

in cement sector

High demandLow demand

Source Martin Schneider 14th ICCC Beijing

0

20

40

60

80

100

120

2020 2025 2030 long term

€/t

CO

2Carbon capture and storage: Cost estimates

oxy-fuel

process

post-

combustion

capture

su

cce

ssfu

l d

em

on

str

atio

n

pro

jects

CCS would

increase

cement costs

substantially

Not viable for

developing

countries

The resources of the earth mean we do not have a lot of options!

11

Only 8 elements constitute >98% or the earth’s crustEven elements we regard as common are more than 1000 times LESS abundant that the elements found in cement – cost and geographical distributionThe composition of the Earth’s Crust limits the possible chemistriesBut the limited range mean we can explore all options

1/1000

How cement works:

Cement grainwater hydrates

reaction with water increases solid volume,

joins grains together

What about the different oxides

Na2O

K2O

Fe2O3

MgO

CaO

SiO2

Al2O3

Too soluble

Too low mobility in alkaline solutions

The most useful

Al2O3CaO

Portland

Cement

14

Hydraulic minerals in the system CaO-SiO2-Al2O3

Calcium aluminate /calcium sulfo aluminate

SiO2

BUT, what sources of

minerals are there

which contain Al2O3 >>

SiO2 ?

Bauxite – localised,

under increasing

demand for Aluminium

production,

EXPENSIVE

Even if all current

bauxite production

diverted would still only

replace 10-15% of

current demand.

Less CaO > less CO2

Portland based cement will continue to be dominant

◼ Incredible economy of scaleClinker very low cost

◼ Raw materials abundant nearly everywhere

◼ Easily to manipulate open time

◼ Robust

Extending use of blended cements

16

Evolution of Clinker substitution

17

2%4%

5% 5% 6% 6% 6% 6% 6% 7% 7% 7%4%

4%

4% 4%5% 5% 5% 5% 5% 5% 5% 5%

1%

2%

3%3%

3%4% 4% 4%

4%4% 4% 4%

1%

2%

2%2%

2%2%

2% 2% 2%2% 2% 2%

4%

2%

1%1%

1%1%

1% 1% 1%1% 1% 1%

0%

5%

10%

15%

20%

25%

1990 2000 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Limestone

Slag

Fly ash

Puzzolana

Others

• Almost no progress in last 5 years

• Only 3 substitutes used in quantity

Clinker substitution most successful strategy to reduce CO2

0 2000 4000 6000

Calcined Clay

Filler

Portland cement

Fly ash

Slag

Natural Pozzolan

Vegetable ashes

waste glass

silica fume

Mt/yr

Used Available

limestone

▪ Blended with SCMs will be best solution for sustainable cements for foreseeable future

▪ Only material really potentially available in viable quantities is calcined clay.

▪ Blend containing combination of calcined clay and limestone are particularly interesting: EPFL led LC3 project supported by SDC. Started 2013

There is no magic solution

19

What is LC3

LC3 is a family of cements,

the figure refers to

the clinker content

0

10

20

30

40

50

60

70

PC LC3-50

Co

mp

ress

ive

str

en

gth

(M

Pa)

1 day

7 days

28 days

90 days

• 50% less clinker

• 30% less CO2

• Similar strength

• Better chloride resistance

• ASR resistant

0

20

40

60

80

100

PC PPC30 LC3-50 LC3-65

Mas

s p

rop

ort

ion

(%

)

Gypsum

Limestone

Calcined clay

Clinker

Why are such high levels of substitution possible

21

◼ Calcination of kaolinite at 700-850°C gives metakaolin: much more reactive than glassy SCMs

» Synergetic reaction of

Alumina in metakaolin

with limestone to give

space filling hydrates

OPC

205 10 15 25Position [ 2Q ]

CHMs

Strät .Strät . C4AF AFtAFtAFt AFtHcMc

MsHc

1d

28d

LC3-50

205 10 15 25

Position [ ]

CHMs

Strät.Strät. C4AF AFtAFtAFt AFtHcMc

MsHc

2Q

1d

28d

silicon

aluminium

Comparison of calcined kaolinitic clay, slag and fly ash

Binary systems 70% clinker

Ternary systems, with limestone 50% clinker

Availability of suitable clays, yellow and pink regions, and others

23

Suitable clays presently stockpiled as waste

LC3 has been produced and used in full scale trials in Cuba and India

A company in Latin America will start full scale production in March/April

Uses existing technologyRotary kiln Flash calcineretc

Cuba: Industrial block manufacture plant

Prefabrication plant Cuba

House built at Santa Clara, Cuba with LC3

India: Evaluation in building materials

India: Industrial production

KJS Concrete Pvt. Ltd., Dadri

India: Demonstration structure

Around 15 tonnes of CO2 saved

Compared to existing solutions

Key Advantages

• Chloride resistance• ASR mitigation

Chloride ingress ASTM

Apparent diffusion coeffs.

Porosity characterization by MIP

◼ Significant refinement of porosity already at 3 days of hydration

LC3-50 (95%) 3d

Very dense

microstructure

Strong pore refinement

Alkali silica reaction

Chappex 2012

Impact of alumina on aggregates

No alumina

Alumina in solution

Global cement production

Billion tons/year

Clinker factor, global

average

%

Global SCM volume

Billion tones/year

Global CO2

reduction

Million tones/year

2006 2.6 79 0.5

2050 (CSI study)

4.4 73 1.2 200

2050 (with LCC)

4.4 60 1.8 600

Global potential of LC3

∆ = 400 million

tonnes per yr

Can replace

whole of need for CCS

in low demand scenario

> whole of CO2

emissions

of France

Potential impact of LC3 technology

IEA study for

CSI of WBCSD

One part of the chain

Reduce CO2

from clinker production

• Efficient plants

• Waste fuels

• Alternate raw

materials

Reduce clinker in cement

Reduce cement

in concrete

Reduce concrete

in building

More efficient (re)use of buildings

• SCMs• Aggregate grading

• Good admixtures

• Use filler

By working throughout the

value chain CO2 emissions

can be reduced by 80%

compared to 1990, without

huge extra costs and using

existing knowledge and

codes

Efficiency of binder use in concrete(29 countries)

0

5

10

15

20

0 20 40 60 80 100

Bin

de

r In

ten

sity

(kg

/m³.

MP

a)

Compressive Strength (MPa)

250kg/m³

DAMINELI, et al . Measuring the eco-efficiency of cement use.

Cement and Concrete Composites, 32, p. 555-562, 2010

Site mixing

Ready-mixed

industrial

Materials wastage

Materials wastage

Materials wastage

Industrialization as mitigation tool

◼ Promote industrialized use of cement

◼ Dry-mix mortar

◼ Industrialized concrete

◼ Concrete components

◼ Ban commercialization of bagged cement in large cities (ex. China)

◼ Mitigation potential: 15% reduction?

High filler, advanced performancewater & binder minimization technology

Good rheology min water

ParticleDispersion

MinimumBinder

Particle packing

Filler without dispersion:agglomeration may increase water demand

Filler + Dispersion: Low water demand for given rheology

Typical cementLEAP cement + filler

Low-Binder concrete formulations(29 countries)

0

5

10

15

20

0 20 40 60 80 100

Bin

de

r In

ten

sity

(kg

/m³.

MP

a)

Compressive Strength (MPa)

250kg/m³

CBI/KTH - Sweden; USP – Brazil; U Darmastad, U Karlsrhue, VDZ - Germany

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itig

atio

nP

ote

nti

al(M

t)

Market Share at 2050 (%)

Efficient concrete

Extending use of SCMs:Calcined Clayand limestone

2 solutions have large potential to reduce CO2

-200

0

200

400

600

800

1000

0 10 20 30 40 50 60 70

CO

2M

itig

atio

nP

ote

nti

al(M

t)

Market Share at 2050 (%)

Geopolymer + Calcined clay

BYF

CCSC

Calcined Clayand limestone

Efficient concrete

CO2 mitigation potential of different technologies

Concluding remarks

◼ Future cements will be based on Portland cement clinker with increasing levels of incorporation of SCMs

◼ Calcined clays are the only realistic option for extending the use SCMs

◼ Possible to obtain similar mechanical properties to OPC / CEM I with 50% clinker and clays with >40% kaolinite

◼ Calcined clays have very positive impact on:

◼ Chloride ingress

◼ ASR

◼ If we are serious about more sustainable concrete we need to use cements with lower CO2 emissions, e.g LC3 clinker/ calcined clay / limestone blends

◼ To go further we need to work through the whole value chain.

◼ Europe has an important role to play in facilitating uptake worldwide:standards and research

THANK YOU!