The Properties of Magnesia - Portland Cement - Pozzolan Blends

8/11/2019 The Properties of Magnesia - Portland Cement - Pozzolan Blends

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New Binders Based on the Addition of ReactiveMagnesia to Hydraulic Cements With or Without

Added Pozzolan.

All I ask is that the industry think about what I am saying.

John Harrison B.Sc. B.Ec. FCPA.

Hobart, Tasmania, Australia


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Construction Industry MineralsVitrified and calcined minerals and their derivatives are the main

materials used to construct the built environment which is our footprint on earth. Globally over 3 billion tonnes of calcined minerals (cement, lime and

magnesia) are produced annually. Global Portland cementproduction is in the order of 1.8 billion tonnes. The largest producersof Portland cement are China at over 500 million tonnes followed byIndia at over 109 million tonnes. The figures for vitrified clays are

substantial but unknown.TecEco estimate that buildings and infrastructure account forover 60% of anthropogenic materials flows.The built environment represents a huge opportunity forsustainability. Greater durability Lower embodied and lifetime energies Waste utilisation and recycling Abatement and better still - sequestration

TecEco technologyaddresssustainability issuesin a holistic way


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Sustainability IssuesCalcined mineral materials and their derivatives used inconstruction such as Portland cement, lime and magnesiaare made from carbonates.The process of calcination involves driving off chemicallybound CO 2 with heat.

MCO 3 MO CO 2

Fuel oil, coal, natural gas or other fuels are directly orindirectly burned to produce the energy required forvitrification of clays and producing calcined materialsreleasing CO 2 .

The production of vitrified and calcined mineral materialsaccounts for around 12% -15% of global anthropogenic CO 2 .


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Talked about Rheology

Time for and method of placing and finishing Shrinkage

Cracking, crack control Durability and Performance

Sulphate and chloride resistance Carbonation Corrosion of steel and other reinforcing Bonding to brick and tiles Alkali aggregate reactions Delayed reactions (eg ettringite)

EfflorescenceRarely discussed Sustainability

Emissions and embodied energies

Should thediscussion bemore abouthow we couldfix thematerial,

overcomingrather thantolerating andmitigatingtheseproblems?

Materials Science Issues with OPC Concrete


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Conclusions?Sustainability can be improved with improved performance(eg.durability) and emissions reductions (lower embodiedenergies).Cementitous calcined mineral materials or compositesincluding OPC concretes offer more scope for sustainabilitythan vitrified minerals.Portlandite is the main problem with Portland cement. Better to fundamentally fix the material than continue with what amount to band

aid fixes. The merits of removing and replacing Portlandite with another less soluble, easily

manufactured alkali should be considered.

Technology improvements increase market share and fueleconomic growth Carbon trading and regulations will favour adoption of better technologies.

The TecEco technology is an opportunity to betaken not a threat to be ignored!


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Partially hydrated Portland cement paste [Soroos,1999 ].

The

consequences ofremovingPortlandite (lime)with thepozzolanicreaction and fillingthe voids betweenhydrating cementgrains withbrucite , aninsoluble alkalinemineral, need tobe considered.

The important thing in science is not so much to obtain newfacts as to discover new ways of thinking about them.

-- Sir William Bragg

TecEco Technology - Simple Yet Ingenious?

Glue as well as Velcro?


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TecEco Cements A Blending System

TecEco cements are a system of blending reactivemagnesia, Portland cement and usually a pozzolan

Imagination is moreimportant than

knowledge,knowledge islimited.

Albert Einstein



TecEco Cement SummaryTwo main formulation strategies so far: TecEco modified Portland cements (eg 10% MgO, 90%

OPC.) Contain more Portland cement than reactive magnesia

Reactive magnesia hydrates in the same rate order as Portland cementforming brucite which densifies, maintains a lower long term pH and dueto its low solubility, mobility and reactivity results in greater durability.

Other benefits include improvements in rheology, the use of a widerrange of aggregates and possibly no shrinkage

TecEco eco-cements (eg 50-75% MgO, 50-25% OPC) Contain more reactive magnesia than Portland cement

Brucite in porous materials eventually carbonates Forming stronger fibrous minerals. Resulting in huge opportunities for abatement.



Reactivity Overcomes Delayed Hydration Problems.

Delayed hydration leads to dimensional distress. Magnesium was banned in Portland cements because when it goes through

the high temperature process of making Portland cement it becomes periclase.It is dead burned, hydrates slowly and causes dimensional distress.

Dead burned lime is much more expansive than dead burned magnesia(1), aproblem largely forgotten about by cement chemists.

The reactivity of magnesia is a function of the state of disorder,

specific surface area and glass forming impurities. The state of disorder is dependent on the temperature of calcining and probably

the most important, followed by the level of impurities such as iron. Make a particle small enough and it will react with just about anything

A new patented TecEco kiln technology which combines calciningand grinding should make it possible to calcine at lower

temperatures and produce more reactive magnesia with reducedproblems due to impurities as well as capture CO 2 .

(1) Ramachandran V. S., Concrete Science, Heydon & Son Ltd. 1981, p 358-360.



Why Replace Portlandite with Brucite?

Portlandite is reactive, carbonates readily and being solublecan act as an electrolyte. TecEco remove Portlandite inreactions with Pozzolans.TecEco replace Portlandite with brucite which is much lesssoluble, mobile and reactive, does not act as an electrolyte orcarbonate as readily. Improving the rheology Using up bleed water as it hydrates Filling in the pores, increasing the density Sealing off the atmosphere

Providing long term pH control with many consequencesincluding greater durability.


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Ramifications of Adding Reactive Magnesia (1)

A low er more S tab le Long Term pH?: As Portlandite isremoved the pH becomes governed by the solubility of bruciteand is much lower at around 10.5 -11, allowing a wider rangeof aggregates to be used without AAR problems. Carbonationis slower and the pH remains high enough to keep Fe FeO andFe

3O

4 stable for much longer.

Durabi l i ty : TecEco modified Portland cements are denser,protected by brucite, are not attacked by salts, do notcarbonate readily and last indefinitely.Easy to Us e: With improved homogeneity and rheology. Fine

magnesia acts as a lubricant for Portland cement.


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Greater Densi ty , redu ced perm eabi l i ty? : Brucite fills porespaces taking up mix and bleed water as it hydrates reducingvoids and shrinkage. (brucite is 58.3 mass% water!)Greater St reng th? Less sh r ink age?: A lower water cementratio could mean greater strength and in the right propotion,no shrinkage.More Su sta inable: TecEco cements and eco-cements use ahigh proportion of recycled materials, immobilise toxic andhazardous wastes, can use a wider range of aggregates

reducing transport emissions and have superior durability.Eco-cements reabsorb chemically released CO 2.


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Ins ula t ing Pro per t ies / High Therm al Mass / Lo wEmbo died Energy: Eco-cement products will be favoured forenergy conserving buildings.Recyclable: Eco-cement products can be reprocessed andreused, making them more attractive to many users.

A Fire Retardan t: Brucite and magnesite are both fireretardants. TecEco cement products put fires out by releasingCO 2 at relatively low temperaturesLo w Capi ta l Cost : No new plant and equipment is required.

Lo w er Mater ia ls Cost : With economies of scale TecEcocements should be cheaper.


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Durability - A Lower More Stable Long Term pH

Eh pH orPourbaixDiagram Thestabilityfields ofiron in thepresenceof oxygenand carbondioxide. Source:Krauskopf K. B.,Introduction toGeochemistry,McGraw HillBook Company,1967, page 168,after Garrels &Christ (1965),

page 224.

TecEcoCementzone.

Long term pH is governed

by the solubility of bruciteand is much lower at around10.5 -11, allowing a widerrange of aggregates to beused, reducing problemssuch as AAR and etching,

but still high enough to keepFe and Fe 3O 4 stable. As thehydroxides of most heavymetals are also least solubleat around pH 10.5 11,TecEco cements aresuitable for toxic andhazardous wasteimmobilisation.


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Durability Reduced Delayed Reactions

A wide range of delayed reactions can occur in Portlandcement based concretes such as delayed alkali silicaand alkali carbonate reactions, the delayed formation ofettringite and thaumasite, delayed hydration of minerals

such as dead burned lime and magnesia.Delayed reactions are reduced in TecEco modifiedPortland cement concretes because: The hydration of magnesia consumes water drying concrete

from the inside out. Reactions occur very slowly by diffusion. A lower long term pH results in reduced reactivity. Potentially reactive ions are trapped in the structure of brucite.


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Durability Rapidly Reduced Pore Water

Ordinary Portland cement concretes can take years todry out. The presence of water allows reactions to occur much more

rapidly than by diffusion.

Reactive magnesia consumes water on hydration

resulting in more rapid onset of a water deficit.Delayed reactions such as: Hydration of dead or hard burned magnesia. The formation of alkali aggregate reaction products. Chlorides, sulphates and carbonates Ettringite and thaumasite.

Are therefore likely to be minimised.


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Durabiliy - Reduced Steel CorrosionA pH of over 8.9 is maintained formuch longer and steel remainspassive.Brucite does not react readilyresulting in reduced carbonationrates and reactions with salts.

Concrete with brucite is denser andcarbonation is expansive, sealingthe surface preventing furtheraccess by moisture, CO 2 and salts.Brucite is less soluble and trapssalts as it forms resulting in lessionic transport to complete acircuit for electrolysis and lesscorrosion.

Anode

Cathode

Ionic transport


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Brucite has always played a protective roleduring salt attack. Putting it in the matrix ofconcretes in the first place makes sense.Brucite does not react with salts becauseof its low solubility (reactivity, mobility) andlower pH (reactivity) Ksp brucite = 1.8 X 10 -11 Ksp Portlandite = 5.5 X 10 -6 Carbonation of brucite is slow G or Brucite = -19.55 G or Portlandite = -64.62

Durability - Reduced Salt Attack and Carbonation

5 orders of magnitude

3 orders of magnitude


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Durability - Increased DensityOn hydration magnesiaexpands 116.9 % fillingvoids and surroundinghydrating cement grains.Brucite is 58.3 % water.Lower water cement ratiosresult in greater density.Greater density results ingreater strength, moredurable concrete with ahigher salt resistance andless corrosion of steel etc.

Picture Courtesy Applied Petrographic Services NSW Aust.


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Durability Reduced Permeability

As bleed water exits ordinary Portland cementconcretes it creates an interconnected pore stucturethat remains in concrete allowing the entry of aggressiveagents such as SO 4--, Cl - and CO 2TecEco modified Portland cement concretes do not

bleed they tend to dry from within.In TecEco modified Portland cement concretes mixwater is used up in the hydration of reactive magnesia

forming brucite

TecEco modified Portland cement concretes are denserand less permeable even to vapours


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Strength - Enhanced Pozzolanic Reactions?With small substitutions by reactive magnesia for OPC it

is likely that the early stage pH during the plastic stageof concrete setting is actually higher due tosupersaturation cause by the additional removal ofwater by magnesia as it hydrates.If there is an early high pH then the pozzolanic and othersilicification reactions should ensue more readily.

13.7

pH

Time

10.4 TecEco Modifified OPC Concretewith 10% reactive ma nesia

OPC Concrete

HYPOTHETICAL PH CURVESOVER TIME


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Strength A lower Water Cement Ratio?

TecEco modified Portland cement concretes haveexcellent rheology resulting in a lower water cementratio.There is a linear correlation between the water cement

ratio and strength.Lower water cement ratios result in greater strength.Water is also removed by brucite as it hydratesincreasing the density.


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Safety Reduced Fire Damage

The main phase in TecEco modified ordinary Portlandcement concretes is brucite.The main phases in TecEco eco-cements are magnesiteand hydromagnesite.Brucite, magnesite and hydromagnesite are excellent

fire retardants and extinquishers.At relatively low temperatures Brucite releases water and reverts to magnesium oxide. Magnesite releases CO2 and converts to magnesium oxide. Hydromagnesite releases CO2 and water and converts to

magnesium oxide.Fires are therefore not nearly as aggressive resulting inless damage to structures.


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Improved RheologySuitable reactive magnesia is much finer than most other

cements such as Portland cement and carries what wesuspect is a high positive surface charge.Finely ground reactive magnesia therefore acts as aplasticiser. Improving rheology

Lower water cement ratio results in greater strength and reducedporosity.

The proportion and cost of binders and plasticisers can bereduced.

Second layer low slump TecEcomodified Portland cement concreteTech Tendons

First layer low slump TecEcomodified Portland cement concrete


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Reasons for Improved Rheology

There are also surface charge affects andwater reducing agents are not required.Reactive Magnesia is a plasticiser as well.

Reactive Magnesiagrains Mean size 6 -10 micron

Portland cement grainsMean size 20 - 60micron

The magnesiagrains act as ball

bearings to thePortland cementgrains and also fillthe voids densifyingthe whole

Smaller grains (egmicrosilica) for evenbetter rheology.


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Potential for Neutral Cure Modified Portland Cement Concretes

90 days28

??

? ?

?

??

?

-.05%

+.05%

Portland Cement

Reactive Magnesia

Composite Curve

+- Fly Ash?

HYDRATION THEN CARBONATION OF REACTIVE MAGNESIA AND OPC


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Volume Changes with TecEco Modified PortlandCements on Carbonation

Consider what happens when Portlandite carbonates:Ca(OH) 2 + CO 2 CaCO 374.08 + 44.01 100 molar mass 33.22 + gas 28.10 molar volumes

18.22% shrinkage

Surface shrinkage causing cracks to appear.Compared to brucite forming magnesite as it carbonates:

Mg(OH) 2 + CO 2 MgCO 358.31 + 44.01 84.32 molar mass 24.29 + gas 28.10 molar volumes

15.68% expansion Slight expansion and densification of the surface preventing further

ingress of CO 2 and carbonation.


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TecEco Eco-Cements - Solving Waste ProblemsThe best thing to do with wastes is if at all possible

to use them. If they cannot directly be usedthen they have to be immobilised.TecEco cements are ideal for immobilising /utilising toxic and hazardous wastes such as flyand bottom ash, iron slags, red mud etc.:

They are more durable. Brucite results in an ideal long term equilibrium pH of 10.5

11 at which most heavy metal hydroxides are relativelyinsoluble.

The OPC in TecEco cements takes up lead.

Homogenous and do not bleed water Not attacked by salts in ground or sea water. Dimensionally more stable with less cracking.


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Toxic and Hazardous Waste Immobilisation

The brucite in TecEcocements has astructure comprisingelectronically neutrallayers and is able toaccommodate a wide

variety of extraneoussubstances betweenthe layers and cationsof similar sizesubstituting formagnesium within the

layers and is known tobe very suitable fortoxic and hazardouswaste immobilisation.

Layers of

electronicallyneutral brucitesuitable fortrappingbalancedcations andanions as well

as othersubstances Salts andother toxicandhazardoussubstancesbetweenlayers


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Sustainability=Abatement=Lower Cost

TecEco cements generally A high proportion of brucite compared to Portlandite is water and of

magnesite compared to calcite is CO 2. Every mass unit of TecEco cements therefore produces a greater volume of

built environment than Portland and other calcium based cements. Lessneed therefore be used reducing costs/energy/emissions.

Improved durability and other properties results in lower long run

costs/energies/emissions due to less frequent replacement. Brucite is less soluble, mobile or reactive than Portlandite and not attacked

by salts. The pH is lower but more stable resulting in less AAR, etching and other

problems but still high enough for longer, maintaining the passivity of steelfor longer.

TecEco eco-cements Carbon dioxide is also reabsorbed by brucite from the atmosphere. Afree resource resulting in carbon sequestration and carbon credits.


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Sustainability=Abatement=Lower Cost (2)Energy costs money and results in emissions and is the largest cost

factor in the production of mineral binders. Whether more or less energy is required for the manufacture of reactive

magnesia compared to Portland cement or lime depends on the stage in theutility adding process.

Volume of built material has greater utility and is more validly compared. The new TecEco kiln technology will result in around 25% less energy being

required and the capture of CO 2 during production resulting in lower costs and

carbon credits.A wider range of aggregates can be utilised without problemsreducing transport and other costs/energies/emissions.The manufacture of reactive magnesia is a benign process that canbe achieved with waste or intermittently available energy.Because reactive magnesia is also an excellent plasticiser, other

costly additives are not required for this purpose.Eco-cement products absorb CO 2 , utilise wastes and can to a certainextent be recycled.


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Basic Chemical Reactions

Notice thelowsolubility ofbrucitecomparedtoPortlandite

and thatmagnesiteis strongerand adoptsa moreideal habitthan calcite& aragonite

Magnesia Brucite

MgO + H 2O Mg(OH) 2

Hardness: 2.5 - 3.0 4.0 3.5

Form: Massive-Sometimes Fibrous Often Fibrous Acicular - Needle-like crystals

Solubility (mol.L -1): .00015 .0013 .0011

Silicates and aluminosilicates

Magnesia Brucite Magnesite Hydromagnesite

MgO + H 2O Mg(OH) 2 + CO 2 MgCO 3 + Mg(OH) 2.4MgO.4CO 2.4H 2O

In Eco - Cements

In TecEco Modified Portland Cements

Hardness: 2.5-3.00 3.0

Form: Massive Massive or crystalline More acicular

Solubility (mol.L -1): .024 .00014

Portlandite Calcite

Ca(OH) 2 + CO 2 CaCO 3

Compare to Portlandite

Aragonite


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The Magnesium Thermodynamic Cycle


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Manufacture of Portland Cement


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Specific Comments Regarding Problems in India

The lower long term pH of TecEco cements means that a widerrange of aggregates can be tolerated without problems. Many problems appear to be due to the failure of contractors to adhere

to reasonable standards, compromising particularly with aggregates.

TecEco cements result in better renders, gunnites and othermortars. Good rheology, white colour, less efflorescence and a better bond to

concrete and tiles (Tile de-bonding appears common)

Greater durability A lower pore water ionic concentration should result in less corrosion of

steel reinforcement and pipes.

Lower pollution, greater sustainability Replacement of topsoil clay bricks etc. with less polluting, excellent

quality bricks, blocks and pavers made substantially with wastes.


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The TecEco Challenge

Although the technology is new and not yet fullycharacterised, TecEco challenge universities andconstruction authorities to come to grips with the newcement technology and quantify performance incomparison to ordinary Portland cement and othercompeting materials.TecEco will do its best to assist. Negotiations are underway in many countries toorganise supplies to allow such scientific endeavour toproceed.TecEco technologies are an opportunity not a threat.


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TecEco Technology SummarySimple, smart and sustainable? TecEco cement technology has resulted in potential solutions to a

number of problems with Portland and other cements includingdurability and corrosion, the alkali aggregate reaction problem andthe immobilisation of many problem wastes and will provides arange of more sustainable building materials.

The right technology at the right time? TecEco cement technology addresses important triple bottom line

issues solving major global problems with positive economic andsocial outcomes.

Climate Change Pollution

Durability Corrosion

ASR Rheology

Shrinkage Placement , Finishing


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Addressing Issues in Concrete ScienceAddressing the research objectives of concrete science.

Durability salt resistance and steel corrosion may become problemsof the past. Lower use of materials and energy

over time saving money and the environment. Lower more stable long term alkalinity.

Reduced AAR and steel corrosion etc. Better rheology.

Lower water cement ratio, less shrinkage, and easier placement.

Other improved properties: Greater density, adjustable placing and finishing times. Fire retarding properties

Lower Costs Making reactive magnesia is a benign process with potential for using waste

energy and capture of CO 2. A wider range of aggregates including wastes will be available

reducing cartage costs and emissions. Water or CO

2 from the air comprise a high mass % and volume % of the

magnesium minerals in TecEco cements. Water and CO 2 are free or attractcarbon credits

Expensive plasticisers are not required


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TecEcos Immediate Focus Form strategic alliances with major companies.Raise money for Research Around 1 millions dollars worth in thepipeline.Concentrate on defined markets for low technical risk products thatrequire minimal research and development and for whichperformance based standards apply. Carbonated products such as bricks, blocks, stabilised earth blocks,

pavers, roof tiles pavement and mortars that utilise large quantities ofwaste and products where sustainability, rheology or fire retardationare an issue. (Mainly eco-cement technology using fly ash).

The immobilisation of wastes including toxic hazardous and otherwastes because of the superior performance of the technology andthe rapid growth of markets. (Eco-cements and modified Portlandcements).

Products such as renders and mortars where excellent rheology andbond strength are required.

Products where extreme durability is required. Products for which weight is an issue.

Continue our awareness campaign regarding TecEco cements, thenew TecEco kiln design and the Tech Tendon method ofprestressing, partial prestressing and reinforcing.


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TecEco Minding the FutureTecEco are aware of the enormous weight of

opinion necessary before standards can bechanged globally for TecEco modified cementconcretes for general use. TecEco already have a number of institutions and universities

around the world doing research.

TecEco have received huge global publicity not all ofwhich is correct and have therefore publicly released thetechnology. TecEco research documents are available from TecEco by request.

Soon they will be able to be purchased from the web site.

Other documents by other researchers will be made available in asimilar manner as they become available.Technology standing on its own is not inherently good. It stillmatters whether it is operating from the right value system andwhether it is properly available to all people.

-- William Jefferson Clinton


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TecEco Eco - Cements for Sustainable Cities


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Manufacture of Eco-Cement Products

CausticMagnesiaCalcinedusing wasteheat and/orsustainableenergy

Flyash

Other ingredientsEco-MasonryProductse.g. Bricks& blocks

Hydration using fluecooling &/orscrubbing water &flue steam.Carbonation usingwarm CO 2 richgases

Coal

Combustion

TecEco - Cements

MagnesiteCoal

Bottom ash &other wastesas aggregates

Eco-Cement One of ManyPossible Manufacturing Scenarios

PortlandCement

CO2


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TecEco Kiln TechnologyRemember:The reactivity of most calcined materials including magnesiais a function of the state of disorder, specific surface areaand glass forming impurities.

What if calcining and grinding occurred at the

same time? Heat would literally be squashed into the material to be

calcined, reducing the risk of overburning. The clastic conditions should increase the state of disorder and

reduce the formation of glasses resulting in greater reactivity. CO 2 could be captured at source. The heat lost through grinding could be used for calcining

resulting in around 25% greater efficiency.


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Energy On a Mass Basis

Relative toRaw MaterialUsed tomakeCement

FromManufactur ingProcessEnergyRelease100%Efficient(Mj.tonne -1)

FromManufacturing ProcessEnergyRelease withInefficiencies (Mj.tonne -1)

RelativeProductUsed inCement

FromManufacturing ProcessEnergyRelease100%Efficient(Mj.tonne -1)

FromManufacturing ProcessEnergyRelease withInefficiencies(Mj.tonne -1)

Relative toMineralResultingin Cement

FromManufacturing ProcessEnergyRelease100%Efficient(Mj.tonne -1)

FromManufacturing ProcessEnergyReleasewithInefficiencies(Mj.tonne -1)

CaCO 3 +Clay 1545.73 2828.69

PortlandCement 1807 3306.81

HydratedOPC 1264.90 2314.77

CaCO 3 1786.09 2679.14 Ca(OH) 2 2413.20 3619.80

MgCO 3 1402.75 1753.44 MgO 2934.26 3667.82 Mg(OH) 2 2028.47 2535.59


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Energy On a Volume Basis

Relativeto RawMaterialUsed tomakeCement

FromManufacturing ProcessEnergyRelease100%Efficient(Mj.metre -3)

FromManufacturing ProcessEnergyRelease withInefficiencies(Mj.metre -3)

RelativeProductUsed inCement

FromManufactur ingProcessEnergyRelease100%Efficient(Mj.metre -3)

FromManufacturing ProcessEnergyRelease withInefficiencies(Mj.metre -3)

Relative toMineralResultingin Cement

FromManufactur ingProcessEnergyRelease100%Efficient(Mj.metre -3)

FromManufacturingProcessEnergyRelease withInefficiencies(Mj.metre -3)

CaCO 3 + Clay 4188.93 7665.75

PortlandCement 5692.05 10416.45

HydratedOPC 3389.93 6203.58

CaCO 3 6286.62 8429.93 Ca(OH) 2 5381.44 8072.16

MgCO 3 4278.39 5347.99 MgO 9389.63 11734.04 Mg(OH) 2 4838.32 6085.41


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Abatement TecEco Eco-Cements

Eco-cements inporous productsabsorb carbondioxide from theatmosphere.Brucitecarbonatesforminghydromagnesiteand magnesite,completing thethermodynamiccycle.

No Capture11.25% mass%reactive magnesia,3.75 mass%Portland cement, 85mass% aggregate.

Emissions

.37 tonnes to thetonne. Aftercarbonation.approximately .241tonne to the tonne.

PortlandCements15 mass% Portlandcement, 85 mass%aggregate

Emissions

.32 tonnes to thetonne. Aftercarbonation.

Approximately .299tonne to the tonne.

Greater Sustainability.299 > .241 >.140 >.113Bricks, blocks, pavers, mortars and pavement made using eco-cement, fly and bottom ash (with capture of CO 2 duringmanufacture of reactive magnesia) have 2.65 times less emissionsthan if they were made with Portland cement.

Capture CO 2 11.25% mass%reactive magnesia,3.75 mass% Portlandcement, 85 mass%aggregate.

Emissions

.25 tonnes to thetonne. Aftercarbonation.approximately .140tonne to the tonne.

Capture CO 2.Fly and Bottom

Ash11.25% mass% reactivemagnesia, 3.75 mass%Portland cement, 85

mass% aggregate.

Emissions

.126 tonnes to the tonne. After carbonation. Approximately .113 tonneto the tonne.

On the basis of the volume of building materials

produced the figures are even better!

85 wt% Aggregates

15 wt%Cement


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Global AbatementWithout CO2

Capture duringmanufacture(billion tonnes)

With CO2

Capture duringmanufacture(billion tonnes)

Total Portland Cement Produced Globally 1.80 1.80

Global mass of Concrete (assuming aproportion of 15 mass% cement)

12.00 12.00

Global CO 2 Emissions from Portland Cement 3.60 3.60

Mass of Eco-Cement assuming an 80%Substitution in global concrete use

9.60 9.60

Resulting Abatement of Portland Cement CO 2 Emissions

2.88 2.88

CO 2 Emissions released by Eco-Cement 2.59 1.34Resulting Abatement of CO 2 emissions bySubstituting Eco-Cement

0.29 1.53


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Abatement from Substitution

Figures are in millions of Tonnes

BuildingMaterial to be

substituted

Realistic %

Subst-itutionbyTecEcotechnology

Size ofWorld

Market(milliontonnes

Substituted

Mass(milliontonnes)

CO2Fact

ors(1)

EmissionFrom

MaterialBeforeSubstitution

Emission/Sequestration from Substituted

Eco-Cement (Tonnefor TonneSubstitutionAssumed)

Net Abatement

Emissions - NoCapture

Emissions - CO2Capture

Abatement - NoCapture

AbatementCO2Capture

Bricks 85% 250 212.5 0.28 59.5 57.2 29.7 2.3 29.8

Steel 25% 840 210 2.38 499.8 56.6 29.4 443.2 470.4

Aluminium 20% 20.5 4.1 18.0 73.8 1.1 0.6 72.7 73.2

TOTAL 426.6 20.7 633.1 114.9 59.7 518.2 573.4

Concretes already have low lifetime energies.

If embodied energies are improved couldsubstitution mean greater market share?


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TecEco Movie Theatre

Discovery Channel Movieon Eco-Cements

Shown courtesy Discovery Channel Canada


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Autogenous healingCoatings a good or a bad thing?

Documents

The Properties of Magnesia - Portland Cement - Pozzolan Blends