Presentation on theme: "Presentation downloadable from www.tececo.com 1 Materials – The Key to Sustainability TecEco are in the BIGGEST Business on the Planet - Solving Sustainability."— Presentation transcript:
Presentation downloadable from 1 Materials – The Key to Sustainability TecEco are in the BIGGEST Business on the Planet - Solving Sustainability Problems Economically The Problem - A Planet in Crisis
Presentation downloadable from 2 A Demographic Explosion Developed Countries Undeveloped Countries Global population, consumption per capita and our footprint on the planet is exploding. ? ?
Presentation downloadable from 3 Atmospheric Carbon Dioxide
Presentation downloadable from 4 Global Temperature Anomaly
Presentation downloadable from 5 The Carbon Cycle and Emissions Source: David Schimel and Lisa Dilling, National Centre for Atmospheric Research 2003 Emissions from fossil fuels and cement production are the cause of the global warming problem
Presentation downloadable from 6 The Techno-Process & Earth Systems Our linkages to the bio-geo- sphere are defined by the techno process describing and controlling the flow of matter and energy. It is these flows that have detrimental linkages to earth systems. Detrimental affects on earth systems Earth Systems Atmospheric composition, climate, land cover, marine ecosystems, pollution, coastal zones, freshwater systems, salinity and global biological diversity have all been substantially affected. Move billion tonnes Use some 50 billion tonnes
Presentation downloadable from 7 Ecological Footprint Our footprint is exceeding the capacity of the planet to support it. We are not longer sustainable as a species and must change our ways
Presentation downloadable from 8 Detrimental Linkages that affect earth system flows Takemanipulateand makeimpacts End of lifecycle impacts Greater Utility Less Utility Materials are in the Techno- sphere Utility zone Materials are everything between the take and waste and affect earth system flows. There is no such place as away There are Detrimental Affects Right Through the Techno-process
Presentation downloadable from 9 Materials Affect Underlying Molecular Flows Take Manipulate Make Use Waste [ Materials ] [ Underlying molecular flow ] Damaging to the Environment e.g. heavy metals, cfcs, c=halogen compounds and CO 2 Materials influence: How much and what we have to take to manufacture the materials we use. How long materials remain of utility, whether they are easily recycled and how and what form they are in when we eventually throw them away. What we take from the environment around us, how we manipulate and make materials out of what we take and what we waste result in underlying molecular flows that affect earth systems.
Presentation downloadable from 10 Innovative New Materials - the Key to Sustainability There is no such place as away, only a global commons The choice of materials controls emissions, lifetime and embodied energies, user comfort, use of recycled wastes, durability, recyclability and the properties of wastes returned to the bio-geo-sphere.
Presentation downloadable from 11 Changing the Techno-process Improving the sustainability of materials used to create the built environment will reduce the impact of the take and waste phases of the techno-process Reduce Re-use Recycle Materials Take => manipulate => make => use => waste Driven by fossil fuel energy with detrimental effects on earth systems. Eco-innovate
Presentation downloadable from 12 Materials & Lifetime & Embodied Energies The embodied energy of materials only contributes 1-2% of the total energy consumed by buildings over their lifetime It follows that the properties of materials such as specific heat and conductance are more important to the overall energy consumption and thus emissions New materials and materials composites can introduce physical properties that result in them being more sustainable in use In many instances wastes will provide the physical properties required Currently unheard of paradigms such as materials with high specific heat and low conductance will increase the performance of buildings An opportunity will emerge to introduce such composites with the introduction of robotics
Presentation downloadable from 13 Economically Driven Sustainability The challenge is to harness human behaviours which underlay economic supply and demand phenomena by changing the technical paradigm in favour of making carbon dioxide and other wastes resources for new materials with lower take and waste impacts and more energy efficient performance. Sustainable processes are more efficient and therefore more economic. Natural ecosystems can be 100% efficient. What is needed are new technologies that allow material and energy flows to more closely mimic natural ecosystems. Innovation will deliver these new technical paradigms. $ - ECONOMICS - $ Sustainability will not happen by relying on people to do the right thing
Presentation downloadable from 14 Sustainability = Culture + Technology Increase in demand/price ratio for sustainability due to educationally induced cultural drift. # $ Demand Supply Increase in supply/price ratio for more sustainable products due to innovative paradigm shifts in technology. Equilibrium shift ECONOMICS Greater Value/for impact (Sustainability) and economic growth Sustainability is where Culture and Technology meet. Demand Supply New Technical Paradigms are required that deliver sustainability.
Presentation downloadable from 15 Changing the Technology Paradigm By enabling us to make productive use of particular raw materials, technology determines what constitutes a physical resource 1 1.Pilzer, Paul Zane, Unlimited Wealth, The Theory and Practice of Economic Alchemy, Crown Publishers Inc. New York.1990 We need materials that require less energy to make them, that last much longer and that contribute properties that reduce lifetime energies. The key is to change the technology paradigm
Presentation downloadable from 16 A Post – Carbon & Waste Age? The construction industry can be uniquely responsible for helping achieve this transition We cannot get there without new technical paradigms.
Presentation downloadable from 17 Biomimicry The term biomimicry was popularised by the book of the same name written by Janine Benyus Biomimicry is a method of solving problems that uses natural processes and systems as a source of knowledge and inspiration. It involves nature as model, measure and mentor. The theory behind biomimicry is that natural processes and systems have evolved over several billion years through a process of research and development commonly referred to as evolution. A reoccurring theme in natural systems is the cyclical flow of matter in such a way that there is no waste of matter or energy.
Presentation downloadable from 18 Utilizing Carbon and Wastes (Biomimicry) During earth's geological history large tonnages of carbon were put away as limestone and other carbonates and as coal and petroleum by the activity of plants and animals. Sequestering carbon in magnesium binders and aggregates in the built environment mimics nature in that carbon is used in the homes or skeletal structures of most plants and animals. We all use carbon and wastes to make our homes! Biomimicry In eco-cement blocks and mortars the binder is carbonate and the aggregates are preferably wastes
Presentation downloadable from 19 Re - Engineering Materials To solve environmental problems we need to understand more about materials in relation to the environment. –the way their precursors are derived and their degradation products re assimilated and how we can reduce the impact of these processes –what energies drive the evolution, devolution and flow of materials and how we can reduce these energies –how materials impact on lifetime energies With the knowledge gained re- design materials to not only be more sustainable but more sustainable in use Environmental problems are the result of inherently flawed materials, materials flows and energy systems
Presentation downloadable from 20 Materials in the Built Environment The built environment is made of materials and is our footprint on earth. –It comprises buildings and infrastructure. Building materials comprise –70% of materials flows (buildings, infrastructure etc.) –40-50% of waste that goes to landfill (15 % of new materials going to site are wasted.) At 1.5% of world GDP Annual Australian production of building materials likely to be in the order 300 million tonnes or over 15 tonnes per person. Over 20 billion tonnes of building materials are used annually on a world wide basis. –Mostly using virgin natural resources –Combined in such a manner they cannot easily be separated. –Include many toxic elements.
Presentation downloadable from 21 Huge Potential for Sustainable Materials Reducing the impact of the take and waste phases of the techno-process. –including carbon in materials they are potentially carbon sinks. –including wastes for physical properties as well as chemical composition they become resources. –re – engineering materials to reduce the lifetime energy of buildings C C C C C Waste Many wastes can contribute to physical properties reducing lifetime energies
Presentation downloadable from 22 Abatement and Sequestration To solve the greenhouse gas problem our approach should be holistically balanced and involve –Everybody, every day –Be easy –Make money TecEco-cements = Low emissions production, mineral sequestration + waste utilization Geological Seques- tration Emissions reduction through efficiency and conversion to non fossil fuels + + TecEcos Contribution New technical paradigms are required Abatement Sequestration and
Presentation downloadable from 23 The TecEco Dream – A More Sustainable Built Environment MAGNESITE + OTHER INPUTS TECECO CONCRETES MINING SUSTAINABLE CITIES CO 2 PERMANENT SEQUESTRATION & WASTE UTILISATION (Man made carbonate rock incorporating wastes as a building material) CO 2 MgO TECECO KILN RECYCLED BUILDING MATERIALS OTHER WASTES CO 2 FOR GEOLOGICAL SEQUESTRATION We need materials that require less energy to make them, that last much longer and that contribute properties that reduce lifetime energies There is a way to make our city streets as green as the Amazon rainforest. Fred Pearce, New Scientist Magazine
Presentation downloadable from 24 Impact of the Largest Material Flow - Cement and Concrete Concrete made with cement is the most widely used material on Earth accounting for some 30% of all materials flows on the planet and 70% of all materials flows in the built environment. –Global Portland cement production is currently in the order of 2 billion tonnes per annum. –Globally over 14 billion tonnes of concrete are poured per year. –Over 2 tonnes per person per annum –Much more concrete is used than any other building material. TecEco Pty. Ltd. have benchmark technologies for improvement in sustainability and properties
Presentation downloadable from 25 Embodied Energy of Building Materials Downloaded from serv/brochures/embodied/embodied.htm (last accessed 07 March 2000) Concrete is relatively environmentally friendly and has a relatively low embodied energy
Presentation downloadable from 26 Average Embodied Energy in Buildings Downloaded from serv/brochures/embodied/embodied.htm (last accessed 07 March 2000) Because so much concrete is used there is a huge opportunity for sustainability by reducing the embodied energy, reducing the carbon debt (net emissions) and improving properties that reduce lifetime energies. Most of the embodied energy in the built environment is in concrete.
Presentation downloadable from 27 Emissions from Cement Production Chemical Release –The process of calcination involves driving off chemically bound CO 2 with heat. CaCO 3 CaO + CO 2 Process Energy –Most energy is derived from fossil fuels. –Fuel oil, coal and natural gas are directly or indirectly burned to produce the energy required releasing CO 2. The production of cement for concretes accounts for around 10% of global anthropogenic CO 2. –Pearce, F., "The Concrete Jungle Overheats", New Scientist, 19 July, No 2097, 1997 (page 14). Arguments that we should reduce cement production relative to other building materials are nonsense because concrete is the most sustainable building material there is. The challenge is to make it more sustainable. CO 2 CO 2
Presentation downloadable from 28 Cement Production ~= Carbon Dioxide Emissions Between tec, eco and enviro-cements TecEco can provide a viable much more sustainable alternative.
Presentation downloadable from 29 Portland Cement & Global Warming Concrete is the third largest contributor to CO 2 emissions after the energy and transportation sectors. The cement industry is growing at around 5% a year globally. Mainly China, Thialand and India. On current trends world production of Portland cement will reach 3.5 billion tonnes by a three fold increase on 1990 levels. To achieve Kyoto targets the industry will have to emit less than 1/3 of current emissions per tonne of concrete. Carbon taxes and other legislative changes will provide legislative incentive to change. There is already strong evidence of market incentive to change
Presentation downloadable from 30 Concrete Industry Objectives PCA (USA) –Improved energy efficiency of fuels and raw materials –Formulation improvements that: Reduce the energy of production and minimize the use of natural resources. Use of crushed limestone and industrial by- products such as fly ash and blast furnace slag. WBCSD –Fuels and raw materials efficiencies –Emissions reduction during manufacture
Presentation downloadable from 31 TecEco Technologies Take Concrete into the Future More rapid strength gain even with added pozzolans –More supplementary materials can be used reducing costs and take and waste impacts. Higher strength/binder ratio Less cement can be used reducing costs and take and waste impacts More durable concretes –Reducing costs and take and waste impacts. Use of wastes Utilizing carbon dioxide Magnesia component can be made using non fossil fuel energy and CO 2 captured during production. Eco-Cements Tec - Cements Tec & Eco- Cements
Presentation downloadable from 32 Greening the Largest Material Flow - Concrete 1.Scale down Production. –Untenable nonsense, especially to developing nations 2.Use waste for fuels –Not my area of expertise but questioned by many. 3.Reduce net emissions from manufacture –Increase manufacturing efficiency –Increase fuel efficiency –Waste stream sequestration using MgO and CaO E.g. Carbonating the Portlandite in waste concrete –Given the current price of carbon in Europe this could be viable TecEco have a mineral sequestration process that is non fossil fuel driven using MgO and the TecEco kiln Not discussed
Presentation downloadable from 33 Greening Concrete 4.Increase the proportion of waste materials that are pozzolanic –Using waste pozzolanic materials such as fly ash and slags has the advantage of not only extending cement reducing the embodied energy and net emissions but also of utilizing waste. We could run out of fly ash as coal is phasing out. (e.g. Canada) TecEco technology will allow the use of marginal pozzolans Slow rate of strength development can be increased using TecEco tec-cement technology. Potential long term (50 year plus) durability issues overcome using tec-cement technology. 5.Replace Portland cement with viable alternatives –There are a number of products with similar properties to Portland cement Carbonating Binders Non-carbonating binders –The research and development of these binders needs to be accelerated
Presentation downloadable from 34 Greening Concrete 6.Use aggregates that extend cement –Use air as an aggregate making cement go further Aluminium use questionable Foamed Concretes work well with TecEco eco-cement Use for slabs to improve insulation 7.Use aggregates with lower embodied energy and that result in less emissions or are themselves carbon sinks –Other materials that be used to make concrete have lower embodied energies. Local aggregates Recycled aggregates from building rubble Glass cullet –Materials that non fossil carbon are carbon sinks in concrete Plastics, wood etc. 8.Improve the performance of concrete by including aggregates that improve or introduce new properties reducing lifetime energies –Wood fibre reduces weight and conductance.
Presentation downloadable from 35 Waste Stream Sequestration is Part of the TecEco Total Process Fe, Ni, Co. Silicate Reactor Process e.g. Mg 2 SiO 4 +2CO 2 =>2MgCO 3 + SiO 2 Silicic Acids or Silica Solar or Wind Electricity Powered Tec-Kiln CO 2 for Geological Sequestration Oxide Reactor Process CO 2 from Power Generation, Industry or CO 2 Directly From the Air Magnesite MgCO 3 ) Crushing Grinding Screening Magnetic Sep. Heat Treatment Serpentine Mg 3 Si 2 O 5 (OH) 4 Crushing Grinding Screening Gravity Concentration Olivine Mg 2 S i O 4 Magnesia (MgO) MgO for TecEco Cements and Sequestration by Eco-Cements in the Built Environment Other Wastes after Processing Tonnes CO2 Sequestered per Tonne Silicate with Various Cycles through the TecEco Process (assuming no leakage MgO to built environment i.e complete cycles) Chrysotile (Serpentinite) Billion Tonnes Forsterite (Mg Olivine) Billion Tonnes Tonnes CO2 sequestered by 1 billion tonnes of mineral mined directly Tonnes CO2 captured during calcining Tonnes CO2 captured by eco-cement Total tonnes CO2 sequestered or abated per tonne mineral mined (Single calcination cycle) Total tonnes CO2 sequestered or abated (Five calcination cycles.) Total tonnes CO2 sequestered or abated (Ten calcination cycles) Total tonnes CO2 sequestered or abated (Twenty calcination cycles) Simplified TecEco Reactions Tec-Kiln MgCO3 MgO + CO kJ/mole Reactor Process MgO + CO 2 MgCO kJ/mole (usually more complex hydrates) Magnesite (MgCO 3 ) CO 2 from Power Generation or Industry Magnesium Thermodynamic Cycle Waste Sulfuric Acid or Alkali? This reaction is how most MgCO3 came to be formed anyway so why are we not using it to also sequester carbon?
Presentation downloadable from 36 TecEco Technologies Provide a Profitable Solution Silicate Carbonate Mineral Sequestration –Using either peridotite, forsterite or serpentine as inputs to a silicate reactor process CO 2 is sequestered and magnesite produced. –Proven by others (NETL,MIT,TNO, Finnish govt. etc.) Tec-Kiln Technology –Combined calcining and grinding in a closed system allowing the capture of CO2. Powered by waste heat, solar or solar derived energy. –To be proved but simple and should work! Direct Scrubbing of CO 2 using MgO –Being proven by others (NETL,MIT,TNO, Finnish govt. etc.) Tec and Eco-Cement Concretes in the Built Environment. –TecEco eco-cements set by absorbing CO2 and are as good as proven. TecEco More Economic under Kyoto? TecEco
Presentation downloadable from 37 TecEco Kiln Technology Can run at low temperatures. Can be powered by variable non fossil fuel energy. Runs 25% to 30% more efficiency. Theoretically capable of producing much more reactive MgO –Even with ores of high Fe content. Captures CO 2 for bottling and sale to the oil industry (geological sequestration). Grinds and calcines at the same time. Part of a major process to solve global CO2 problems. Will result in new markets for ultra reactive low lattice energy MgO (e.g. cement, paper and environment industries) TecEco need your backing to develop the kiln
Presentation downloadable from 38 Increasing the Proportion of Waste Materials that are Pozzolanic Advantages –Lower costs –More durable greener concrete Disadvantages –Rate of strength development retarded –Potential long term durability issue due to leaching of Ca from CSH. Glasser and others have observed leaching of Ca from CSH and this will eventually cause long term unpredictable behavior of CSH. Resolved by presence of brucite in tec-cements –Higher water demand due to fineness. –Finishing is not as easy Supported by WBCSD and virtually all industry associations Driven by legislation and sentiment
Presentation downloadable from 39 Impact of TecEco Tec-Cement Technology on the use of Pozzolans In TecEco tec-cements Portlandite is generally consumed by the pozzolanic reaction and replaced with brucite –Increase in rate of strength development particularly in the first 3-4 days. Internal consumption of water by MgO as it hydrates reducing impact of fineness demand More pozzolanic reactions Mg Al hydrates? –Improved durability as brucite is much less soluble or reactive Potential long term durability issue due to leaching of Ca from CSH resolved. –Improved finishing as Mg++ contributes a strong shear thinning property
Presentation downloadable from 40 Portlandite Compared to Brucite PropertyPortlandite (Lime)Brucite Density Hardness2.5 – 3 Solubility (cold)1.85 g L -1 in H 2 O at 0 o C0.009 g L -1 in H 2 O at 18 o C. Solubility (hot).77 g L -1 in H 2 O at 100 o C.004 g L -1 H 2 O at 100 o C Solubility (moles, cold) M L M L -1 Solubility (moles, hot) M L M L -1 Solubility Product (K sp )5.5 X X ReactivityHighLow FormMassive, sometime fibrous Usually fibrous Free Energy of Formation of Carbonate G o f kJ.mol kJ.mol kJ.mol -1 (via hydrate) Cement chemists in the industry should be getting their heads around the differences
Presentation downloadable from 41 Tec-Cement Concrete Strength Gain Curve The possibility of high early strength gain with added pozzolans is of great economic and environmental importance. We have observed this kind of curve with over 300 cubic meters of concrete
Presentation downloadable from 42 Replacement of PC by Carbonating Binders Lime –The most used material next to Portland cement in binders. –Generally used on a 1:3 paste basis since Roman times –Non-hydraulic limes set by carbonation and are therefore close to carbon neutral once set. CaO + H 2 O => Ca(OH) 2 Ca(OH) 2 + CO 2 => CaCO gas molar volumes –Very slight expansion, but shrinkage from loss of water.
Presentation downloadable from 43 Replacement of PC Carbonating Binders Eco-Cement (TecEco) –Have high proportions of reactive magnesium oxide –Carbonate like lime –Generally used in a 1:5-1:12 paste basis because much more carbonate binder is produced than with lime MgO + H 2 O Mg(OH) 2 Mg(OH) 2 + CO 2 + H 2 O MgCO 3. 3H 2 O molar mass (at least!) gas molar volumes (at least!) –307 % expansion (less water volume reduction) producing much more binder per mole of MgO than lime (around 8 times) –Carbonates tend to be fibrous adding significant micro structural strength compared to lime Mostly CO 2 and water
Presentation downloadable from 44 Replacement with Non Carbonating Binders There are a number of other novel cements with intrinsically lower energy requirements and CO 2 emissions than conventional Portland cements that have been developed –High belite cements Being research by Aberdeen and other universities –Calcium sulfoaluminate cements Used by the Chinese for some time –Magnesium phosphate cements Proponents argue that a lot stronger than Portland cement therefore much less is required. Main disadvantage is that phosphate is a limited resource –Geopolymers
Presentation downloadable from 45 Geopolymers Geopolymers consists of SiO 4 and AlO 4 tetrahedra linked alternately by sharing all the oxygens. –Positive ions (Na +, K +, Li +, Ca ++, Ba ++, NH 4 +, H 3 O + ) must be present in the framework cavities to balance the negative charge of Al 3+ in IV fold coordination. Theoretically very sustainable Unlikely to be used for pre-mix concrete or waste in the near future because of. –process problems Requiring a degree of skill for implementation –nano porosity Causing problems with aggregates in aggressive environments –no pH control strategy for heavy metals in waste streams
Presentation downloadable from 46 TecEco Cements SUSTAINABILITY DURABILITYSTRENGTH TECECO CEMENTS Hydration of the various components of Portland cement for strength. Reaction of alkali with pozzolans (e.g. lime with fly ash.) for sustainability, durability and strength. Hydration of magnesia => brucite for strength, workability, dimensional stability and durability. In Eco-cements carbonation of brucite => nesquehonite, lansfordite and an amorphous phase for sustainability. PORTLAND + or - POZZOLAN MAGNESIA TecEco concretes are a system of blending reactive magnesia, Portland cement and usually a pozzolan with other materials and are a key factor for sustainability.
Presentation downloadable from 47 The Magnesium Thermodynamic Cycle CO 2 Capture Non fossil fuel energy Calcination We think this cycle is relatively independent of other constituents
Presentation downloadable from 48 TecEco Cement Technology Theory Portlandite (Ca(OH) 2 ) is too soluble, mobile and reactive. –It carbonates, reacts with Cl - and SO 4 - and being soluble can act as an electrolyte. TecEco generally (but not always) remove Portlandite using the pozzolanic reaction and TecEco add reactive magnesia –which hydrates, consuming water and concentrating alkalis forming brucite which is another alkali, but much less soluble, mobile or reactive than Portlandite. In Eco-cements brucite carbonates
Presentation downloadable from 49 TecEco Formulations Tec-cements (Low MgO) –contain more Portland cement than reactive magnesia. Reactive magnesia hydrates in the same rate order as Portland cement forming Brucite which uses up water reducing the voids:paste ratio, increasing density and possibly raising the short term pH. –Reactions with pozzolans are more affective. After all the Portlandite has been consumed Brucite controls the long term pH which is lower and due to its low solubility, mobility and reactivity results in greater durability. –Other benefits include improvements in density, strength and rheology, reduced permeability and shrinkage and the use of a wider range of aggregates many of which are potentially wastes without reaction problems. Eco-cements (High MgO) –contain more reactive magnesia than in tec-cements. Brucite in porous materials carbonates forming stronger fibrous mineral carbonates and therefore presenting huge opportunities for waste utilisation and sequestration. Enviro-cements (High MgO) –contain similar ratios of MgO and OPC to eco-cements but in non porous concretes brucite does not carbonate readily. –Higher proportions of magnesia are most suited to toxic and hazardous waste immobilisation and when durability is required. Strength is not developed quickly nor to the same extent.
Presentation downloadable from 50 TecEco Cements – Impact on Sustainability The CO 2 released by calcined carbonates used to make binders can be captured using TecEco kiln technology. Tec-Cements Develop Significant Early Strength even with Added Supplementary Materials. –Around % less total binder is required for the same strength. Eco-cements carbonate sequestering CO 2 requiring 25-75% less binder in some mixes Both tec and eco=cements provide a benign low pH environment for hosting large quantities of waste overcoming problems of: –Using acids to etch plastics so they bond with concretes. –sulphates from plasterboard etc. ending up in recycled construction materials. –heavy metals and other contaminants. –delayed reactivity e.g. ASR with glass cullet –Resolving durability issues
Presentation downloadable from 51 Benefits to the Concrete Industry of Adopting TecEco Technology Utilizing wastes to make concretes. –Tec-cements have more rapid strength development with fly ash, bottom ash, industrial slags etc. (Tec-Cements.) Reducing energy and emissions during the production of cements. –MgO can be made using non fossil fuel energy Concretes containing MgO –are demonstrably more durable. –can incorporate wastes that contribute to physical properties reducing lifetime energies It makes sense to sequester carbon by allowing MgO to re-carbonate and thereby gain strength. The biggest business on the planet is going to be the sustainability business
Presentation downloadable from 52 More rapid strength gain even with added pozzolans –More supplementary materials can be used reducing costs and take and waste impacts. Higher strength/binder ratio Less cement can be used reducing costs and take and waste impacts More durable concretes –Reducing costs and take and waste impacts. Use of wastes Utilizing carbon dioxide Magnesia component can be made using non fossil fuel energy and CO 2 captured during production. Eco-Cements Tec - Cements Tec & Eco- Cements TecEco Technologies Take Concrete into the Future
Presentation downloadable from 53 Using Aggregates that Extend Cement Air used in foamed concrete is a cheap low embodied energy aggregate and has the advantage of reducing the conductance of concrete. –Concrete, depending on aggregates weighs in the order of 2350 Kg/m 3 –Concretes of over 10 mp as light as 1000 Kg/m 3 can be achieved. –At 1500 Kg/m3 25 mpa easily achieved. From our experiments so far with Buildlite Cellular Concrete PL tec-cement formulations increase strength performance by around 5-10% for the same mass. Claimed use of aluminium and autoclaving to make more sustainable blocks questionable
Presentation downloadable from 54 Use Aggregates with Lower Embodied Energy and that Result in less Emissions or that are Themselves Carbon Sinks Use of aggregates that lower embodied energies –wastes such as recycled building rubble tec and eco-cements do not have problems associated with high gypsum content Use of other aggregates that include non fossil carbon –sawdust and other carbon based aggregates can make eco-cement concretes a net carbon sink. Reduce transport embodied energies by using local materials such as earth –mud bricks and adobe. –our research in the UK and with mud bricks in Australia indicate that eco-cement formulations seem to work much better than PC for this
Presentation downloadable from 55 Improve the Performance of Concrete by Including Aggregates that Improve or Introduce New Properties Reducing Lifetime Energies Rather than be taken to landfill many wastes can be used to improve properties of concrete that reduce lifetime energies. –For example paper and plastic have in common reasonable tensile strength, low mass and low conductance and can be used to make cementitious composites that assume these properties