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Karen Scrivener, EPFL, Switzerland
Vanderley John, USP, Brazil
Ellis Gartner, Imperial College, UK
Can be downloaded free at multiple sites.
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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!