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Modern cements
Colum McCagueMPA Cement
Concrete and Masonry Roadshow, Manchester, 15th June 2017
Contents
• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
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• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
Contents
What is Portland cement? SiO2
CaO Al2O3,
Fe2O3limestone
calcareous
[1] Lea’s Chemistry of Cement and Concrete, P. Hewlett (ed), 2001.
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What is Portland cement? SiO2
CaO Al2O3,
Fe2O3
shale
limestone
calcareous
argillaceous
[1] Lea’s Chemistry of Cement and Concrete, P. Hewlett (ed), 2001.
PC
C3AC4AF
C2S
C3S
Manufacture
• Limestone and shale in kiln at 1450C
• Significant thermal and electrical energy required for process
• CO2 emitted from decomposition of limestone and burning of kiln fuel
What is Portland cement?
Energy andCarbon intensive!
Image source: Cement Technology Roadmap: Carbon emissions reductions up to 2050, WBCSD and IEA, 2009.
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The UK ‘carbon’ storyAlternative fuels
Fossil fuels
Calcination
[2] http://cement.mineralproducts.org/documents/MPA_Cement_SD_Report_2015.pdf
UK Portland cement industry CO2 emissions 1998-2015 [2]
• CO2 emissions (per tonne of cement production) have significantly reduced over past 30 years
• In 2015, UK emissions per tonne of cement had declined by 23% since 1998 levels
How do we reduce carbon?
Modern plant/processes• e.g. precalciner, milling
technology
Alternative raw materials• e.g. pfa, iron components
Alternative fuels• e.g. biomass/tyre chips
Alternative fuels
Fossil fuels
Calcination
[2] http://cement.mineralproducts.org/documents/MPA_Cement_SD_Report_2015.pdf
UK Portland cement industry CO2 emissions 1998-2015 [2]
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How can we meet our ambitious targets?
1990-2010 emissions
Scenario 1 tCO2e
Scenario 1 tCO2e
MPA Cement 2050 strategy [3]
Improve and develop current approaches
Develop and introduce• Low carbon cements• Carbon capture and storage/use
[3] http://cement.mineralproducts.org/documents/MPA_Cement_2050_Strategy.pdf
• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
Contents
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‘Hierarchy of standards’
EN 197-1 Cement
• European cement standard published in 2000
• Composition, specifications and conformity criteria for common cements• E.g. CEM I, CEM II, CEM III..
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Extract from Table 1 of BS EN 197-1
Up to 95% clinker substitution
Up to 55% clinker substitution
Up to 20% clinker substitution
Up to 35% clinker substitution
EN 197-1 cements for UK concrete
CEM I
CEM II/A
CEM II/B
CEM III/A
CEM III/B
CEM III/C
CEM II/A
LimestoneClinker
FA/Slag
CEM IV/B
EN 197-1 cements for UK concrete
• Narrow range of EN 197-1 cements permitted in BS 8500
• Rely heavily on FA and ggbs!
Can we optimise limestone??
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CEM I
CEM II/A
CEM II/B
CEM III/A
CEM III/B
CEM III/C
CEM II/A
LimestoneClinker
FA/Slag
CEM IV/B
CEM II/B-M
CEM II/A-M
EN 197-1 cements for UK concrete
• Ternary ‘CEM II-M’ cements are available!
• MPA currently working with BSI to have CEM II-M cements approved in BS 8500
CEM I
CEM II/A
CEM II/B
CEM III/A
CEM III/B
CEM III/C
CEM II/A
LimestoneClinker
FA/Slag
CEM IV/B
CEM II/B-M
CEM II/A-M
CEM VI
CEM II/C-M
EN 197-1 cements for UK concrete
• Ternary ‘CEM II-M’ cements are available!
• MPA currently working with BSI to have CEM II-M cements approved in BS 8500
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• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
Contents
• Cementitious materials manufactured from novel, low energy processes with similar performance to that of traditional Portland based cements
• Burning of limestone is usuallyreduced or even totally eliminated in order to reduce CO2
What are novel cements?
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• Burning of limestone is reduced • Partial replacement in kiln with other minerals
e.g. bauxite (calcium aluminate cement)
• Burning of limestone is eliminated• Full replacement in kiln with other minerals
e.g. magnesite (magnesia cements)
• Chemical activation of cementitious materials e.g. alkali activated slag cements
What are novel cements?
Magnesia cement invented in 1866Magnesia cement invented in 1866
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Alkali-activated slag invented in 1895
Alkali-activated slag invented in 1895
Magnesia cement invented in 1866Magnesia cement invented in 1866
Alkali-activated slag invented in 1895
Alkali-activated slag invented in 1895
Magnesia cement invented in 1866Magnesia cement invented in 1866
Calcium aluminate cement invented in 1908
Calcium aluminate cement invented in 1908
Novel cements?
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Lower CO2 than Portland based cements
Good efficiency of plant and processes
Good availability of raw materials
Similar performance and characteristics to Portland cement
What are we looking for?
CEM I
SiO2
CaO Al2O3
• Portland cement
• Manufacture • Limestone + shale
in kiln at up to 1450C
To recap..
PC
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SiO2
CaO Al2O3
• Calcium aluminate cement• (e.g. ciment fondu)
• Manufacture • Less limestone + bauxite
in kiln at up to 1600C
• CEM I alternative?x CO2 savings are negligiblex Bauxite availability
Novel cements (in brief)
PC
CAC
SiO2
CaO Al2O3
• Calcium silicate cement• (e.g. Solidia cement)
• Manufacture • Less limestone + quartz in kiln at 1200C• Cured by reaction with CO2
• CEM I alternative? 30% reduction in CO2
up to 70% after sequestration!~ Limited to precast
Novel cements (in brief)
PC
CSC
CAC
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SiO2
CaO Al2O3
• Calcium hydrosilicate cement• (e.g. Celitement)
• Manufacture • Less limestone in kiln at 1000C• Lime + quartz interground and
treated in autoclave
• CEM I alternative? 50% reduction in CO2
~ Slow production rate
Novel cements (in brief)
PC
CHC
CSC
CAC
SiO2
Al2O3
• Calcium sulfoaluminate cements• (e.g. Aether, ALI CEM)
• Manufacture • Less Limestone, bauxite + gypsum
in kiln at 1300C
• CEM I alternative? 25-30% reduction in CO2
Identical plant/processes to PC~ Up to 10% more alumina required
Novel cements (in brief)
PC
CHC
CSAC
CSC
CAC
CaO
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SiO2
CaO Al2O3
• Alkali activated materials• (e.g. Cemfree)
• Manufacture • Calcium and silicon-rich (e.g. ggbs)
or aluminium and silicon-rich (e.g. pfa) materials combined with alkali activator
• CEM I alternative? 9 - 80% reduction in CO2
[4]
~ Raw material availability
Novel cements (in brief)
[4] Handbook of Alkali-Activated Cements, Chindaprasit, P. and Leonelli, C. (eds), 2014.
mk
ggbs
PC
CHC
CSC
CAC
CSAC
SiO2
CaO Al2O3
PC
• Geopolymer cement• (e.g. BanahCEM, E-crete)
• Manufacture • Low-calcium alkali activated
system[4]
• CEM I alternative? 9 - 80% reduction in CO2
[4]
~ Raw material availability
Novel cements (in brief)
CHC
[4] Handbook of Alkali-Activated Cements, Chindaprasit, P. and Leonelli, C. (eds), 2014.
mk
ggbs
‘Geopolymer’ cementCSC
CAC
CSAC
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Contents
• What is Portland cement?• Manufacture• Carbon reduction strategy
• Alternative cements• Calcium aluminate cement• Calcium silicate cement• Calcium hydrosilicate cement• Alkali-activated cement• ‘Geopolymer’ cement
• Current position and outlook• Conclusions
CO2e of EN 197-1 cements
913
762
640
490 504
CEM I CEM II/A-L CEM II/B-V CEM III/A CEM IV/B-V
18%
lim
esto
ne
30%
pfa
50%
sla
g
45%
pfa
Por
tland
cem
ent
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913
762
640
490 504
684.75640
456.5
182.6
CEM I CEM II/A-L CEM II/B-V CEM III/A CEM IV/B-V SABC CSC CHC AACM
CO2e of EN 197-1 cements vs. alternatives
800
18%
lim
esto
ne
30%
pfa
50%
sla
g
45%
pfa
Por
tland
cem
ent
360
After sequestration
Aet
her
Sol
idia
Cel
item
ent
- 46% CO2e
- 30% CO2e- 30% CO2e
AA
M
• In terms of embodied CO2 alternative cements are showing good promise
• But..• Lack of experience/history of use• Lack of Codes and Standards• Concerns about raw material
availability• Concerns about durability
Current position..
Company data/technical reports
Certification/Tech Approval
Publicly Available Specification
National Standard
EN Standard
ISO
‘Standardization process’
Novel cements
Current cements
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• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
Contents
• Drafting of European standards for SABC (e.g. Aether) now underway
• PAS 8820 (UK) for alkali activated and ‘geopolymer’ cement published in April 2016• Sponsored by HS2
Standards development
http://www.ecobinder-project.eu
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• UK cement companies are currently considering uptake/implications of emerging alternative cements
• However until standards are devised the main focus is to further reduce emissions through improvements to current PC production processes
MPA outlook..
• What is Portland cement?
• Manufacture
• Carbon reduction strategy
• Low carbon cements
• EN 197-1 cements
• Novel cements
• Current position and outlook
• Conclusions
Contents
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• Modern Portland cements are becoming more sustainable due to ongoing improvements in plant and processes
• Development of Codes and Standards will encourage UK cement companies to develop alternative/novel cements for their product portfolios
• It is very unlikely that alternative cements will replace common Portland based cements but.. the cement industry is eager to embrace these new innovations where possible
Conclusions
Thank you!
