municipalika-capex-iipm 201838 reduce net emissions from manufacture • increase manufacturing...
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Municipalika-CAPEx-IIPM 2018
Technical Session-T5
Innovations in the use of Cement, Concrete and Composites. Construction Chemicals and Performance Enhancers
‘Sustainable Concrete– The Road Ahead’
20 September 2018
Jose Kurian Chairman BIS-CED2
Sustainable Development
• The development that meets the need
of the present without compromising
the ability of future generations to meet
their own.
SCOPE
• Resource consumption
• Material Utilization
• Energy demand optimization
• Emission loadings
• Life Cycle Impact
• Disaster risk response
• Commuting and transport
Managing Sustainability
• Technology
• Climate Change
ISO 14001-1996
Reduced raw material/resource use
Reduced energy consumption
Improved process efficiency
Reduced waste generation and disposal
Utilisation of recoverable costs
Environmental Challenges
Aggregate Shortage
Durability
Energy Savings
Health
Leakage
Noise Pollution
Radiation
Safety
Water
Waste
Sustainability-Holistic Approach
Safety
Durability
Serviceability
Economic Feasibility
Environmental Compatibility
Social Responsibility
Sustainability
Economy
Social Development
Environmental Challenges
Sustainability
• Reduce the Life Cycle Cost by – Improving Service Life,
– Reduce Waste,
– Reuse
– Recycle
Life Cycle
Management of Economic Sustainability
• Financial soundness
• Benefit cost analysis
• Adherence to performance standards
• Economic performance
• Service Quality
• Adaptability
Management of Social Sustainability
• Health, hygiene
• Safety and security
• Labor Rights Protection
• Training, Education and Growth
• Equal Opportunity and Non-discrimination
• Stakeholder participation
• Integrity & Ethical behavior
• Privacy and dignity
National Building Code of India Part-11, Approach to Sustainability
• The Need for Sustainable Development
• Elements of Sustainability
• Life Cycle Sustenance
• Technology Options
• Energy Efficient Design and Processes
• Reduced Embodied & Operational Energy
• Integrated Water Management
• Operation and Maintenance of Services
• Monitoring Compliances
• Corporate Governance
• Disaster Preparedness
Need for Sustainable Development
• Building
– construction,
– occupancy and
– additions/alterations including
– preventive and remedial maintenance
• are always energy and material intensive. Large amount of primary form of natural materials, water, air, energy, etc, are consumed.
Project Lifecycle
• Planning and Design Stage
• Sustainable Construction Management
Processes
– Siting, form and design
– External development and landscape
– Envelope optimization materials
– Water and waste management
– Building services optimization
SITING, FORM AND DESIGN
• EXTERNAL DEVELOPMENT AND LANDSCAPE
• ENVELOPE OPTIMIZATION
• MATERIALS
• WATER AND WASTE MANAGEMENT
• BUILDING SERVICES OPTIMIZATION
• CONSTRUCTIONAL PRACTICES
• COMMISSIONING, OPERATION, MAINTENANCE AND
• BUILDING PERFORMANCE TRACKING
Energy
• Embodied energy,
• Recurring operation energy,
• Refurbishment energy, and
• End of life disposal
CONCRETE
• Concrete is the most widely used construction material
• It is said that per capita consumption of Concrete is next only to Water
• Has impact on all economic activities on an average it is 4 % of GDP, for china it is 16 %.
• Resistance to Environment elements
• Easy to produce
• Can be formed in to any shape easily
Concrete
• Each year the world produces a quantity of concrete equivalent to a mountain with a footprint of
1Km. X 1Km. and about the height of Mount Everest!
CONCRETE
• One of the most economical material
• Mostly locally available
• Relatively less skill and equipment required to produce
• This apparent simplicity in producing concrete at times becomes its nemesis
Concrete- Evolution in Focus & Direction
Safety
Durability
Serviceability
Sustainability
Concrete
• Consumption 450 – 475 m m3
• Plant Mixing 90 m m3
• Field Mixing 350 m m3
• Pre-cast Concrete 15 m m3
LCC
• Life Cycle Cost (LCC)
• LCC analysis is a powerful tool to compare different design alternatives and materials on an economical basis.
• Low investment/initial cost often require higher cost of maintenance and repair during the lifetime of a structure.
• High Performance concrete has thus an advantage in LCC to have lower maintenance cost.
Life Cycle Assessment, Cradle to Grave (ISO 14040:2006)
Raw material acquisition
Production
Use
End-of-life treatment
Recycling
Final disposal
Sustainable Design
Sustainability • Embodied Energy
– Mineral Extraction
– Processing
– Transportation
– Mixing
– Placing
• Generally production of one ton of cement releases about a Ton of CO2 (Green House Gas) to the environment
• Technologies are being developed to bring down this value to as low as 400-450 Kg/Tonne
Typical CO2 Emission from Concrete
• Cement 0.095 62.75 %
• Admixtures 0.002 1.20 %
• Reinforcement 0.012 7.50 %
• Finishes 0.002 1.40 %
• Aggregates 0.003 1.70 %
• Production Process 0.025 16.20 %
• Transport 0.013 8.70 %
Alternate Fuels
• Natural Gas in place of coal
• Waste Tyres
• Biomass
• Used Solvents
• Sewage Sludge
• Municipal Solid Waste
• Petrolium coke
• Other wastes
New Types of Cement Binders
– Alkali activated fly ash and slag CO2 Saved is 80%
– ( In China it is called E-Crete)
– Fly ash based Geo polymer
– Sulphur based binder
– Fal-G
– Slag-gypsum cement
Materials
• Recycled Demolition Waste Aggregate
• Recycled Concrete Aggregate
• Blast furnace Slag
• Manufactured Sand
• Glass Aggregate
• Fly ash
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Scientific Approach to Concrete Design
• Optimization of particle packing will improve – The strength/cost ratio and – Concrete sustainability
• Less cement for the same strength
• Improving packing (other parameters being equal) leads to an increase of: – The compressive and tensile strength – The workability – The durability And a decrease of: – The porosity – The risk of segregation – The yield stresses (easier to compact)
• Could help improve the skill level in the industry
Mix Design
• Optimizes void space between aggregates by optimizing particle proportions and packing of materials. This makes more effective use of the cement binder.
• Aggregates replace excess cement paste to give improved stability, less shrinkage and increase in strength & durability.
• Less cement also generates less heat of hydration.
Mix Design
• The slump of the concrete and its flow are a function of the shape & the quantity of the predominant size of the aggregate in the mix.
• Use of more fine aggregate gives higher slump & flow. So the optimum proportions of coarse & fine aggregate must be critically found to have the best and dense concrete in both fresh & hardened stage of concrete.
Improved Properties
• Mix can result in a reduced paste volume within the concrete structure resulting in a higher level of protection against concrete deterioration.
• Higher strength per kilogram of cement
• Increased durability & lower permeability
• More aggregates typically mean higher Modulus of elasticity.
Advantages • User-friendly
• Optimized mix designs mean easier handling, better consistency and easier finishing
• Reduction in shrinkage & creep
• Green Concrete uses local and recycled materials in concrete.
• The heat of hydration of green concrete is significantly lower than traditional concrete
• This result in a lower temperature rise in large concrete pours which is a distinct advantage for green concrete.
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Increasing the Proportion of Waste Materials that are Pozzolanic
• Advantages
– Lower costs – More durable greener concrete
• Disadvantages
– Rate of strength development retarded
• Resolved by technology
– Potential long term durability issue due to leaching of Ca from CSH.
– Higher water demand due to fineness.
– Finishing is not as easy
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Reduce Net Emissions from Manufacture
• Increase manufacturing efficiency – Has the industry reached the point of diminishing returns?
• Wet to dry process, heat exchangers etc
– Combining calcination with size reduction using a new type of kiln may reduce energy consumption by 20-30%
• Reason - about 98% of the energy of grinding actually goes into cleaving minerals
• Around 30% of the energy used to make cement is used for grinding
• CO2 capture – Calcination in an oxygen atmosphere to capture pure CO2
• Would make capture of CO2 more worthwhile but cost money
– Use of CO2 for carbonation of concrete seems pointless
• Better to use new technologies e.g. algal bioreactor on site
Other Solutions
• Improvements & more efficient Cement production
• Use of alternative fuels
• Carbon capture and storage
– Industrial use of CO2 & Storage
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Technologies that Introduce New Properties
• Introduce new components that improve performance.
– Reducing lifetime energies in use e.g. • That reduce conductance
• That increase specific heat capacity
– Reduce weight/strength ratio • Organic fibres and fillers
– Many of the above components can be wastes
– Improve durability • Remove lime by adding pozzolans
Declaration & Labelling
• Environment product declaration
–Type I : Product meets certain Defined criteria like ISO 14021
–Type II: Self Declaration System declaration without third party evaluation (provision is available in ISO 14021
–Type III: System based on birth to grave evaluation by a third party as per ISO 14040-43
Aggregates
• Both Coarse Aggregates and Fine Aggregates are in short supply today due to ban on mining in a number of states enforced on account of environment protection laws.
• There is an urgent need to overcome these shortages through manufactured aggregates.
• Several technologies are available like sintered flyash already in vogue elsewhere.
• Recycling of construction waste is another option.
• A pilot plant is already in operation in Delhi.
Aggregates from Wastes
• Fly Ash as fine aggregates • Sintered fly Ash • Manufactured Sand • Copper Slag as Fine Aggregates • L D Slag as fine Aggregates • Blast Furnace Slag as Fine Aggregates • Iron and Steel Slag as Fine Aggregates • C &D Waste as
– Recycled Aggregates RC – Recycled Concrete Aggregates RCA
Definitions
In the present discussion, the following definitions will be adopted;
• RCA: Recycled concrete aggregate. (Predominantly from demolition waste concrete).
• RA: Recycled aggregate. (Predominantly demolition waste including concrete, masonry and asphalt).
• LCAgg: Left-over concrete aggregate.
(Aggregate processed from hardened left-over concrete of known composition that has not been in use and has not been contaminated in storage; typically from RMC plants, and precast concrete plants).
Areas of application
After proper processing involving removal of contaminants through selective demolition, screening, and /or air separation and size reduction to aggregate sizes, crushed concrete can be used as:
• Structural grade concrete,
• New concrete for pavements, shoulders, median barriers, sidewalks, curbs and gutters, and bridge foundations,
• Lean-concrete bases,
• Bituminous concrete, and
• Soil-cement pavement bases.
Use of Recycled Aggregates
• Aggregates form bulk volume of concrete. • IS:383 provides for aggregates specifications. • Mostly aggregates are derived from natural resources. • As a result, construction is becoming costlier and lot of time is
wastes. • Recycled concrete Aggregates, (RCA) generally pass the crushing
strength requirements as for conventional aggregates. • However, RCA also contain hydrated cement paste. This causes
reduction in specific gravity and increase in porosity in comparison to virgin aggregates.
• Thus, the paste-aggregate bond is weaker causing reduction in strength and workability.
• BS-8500 allows 30% replacement of natural course aggregate by recycled aggregates
Mineral Admixtures
Used to enhance the properties of Concrete
Fly ash
Silica Fume
Finely Ground Slag
Ground Granulated Blast Furnace Slag (GGBS)
Rice Husk Ash
Metakaoline
Lime Stone Powder
Construction Chemicals
• Chemical Admixture to Concrete – Retarders
– Water reducing agents
– Superplasticizers
– Shrinkage reducing admixtures
• Repair and Rehabilitation Material
• Corrosion Inhibitors
• Waterproofing chemicals
• Curing Compounds
• Shotcrete Admixtures
• Floor Finishes, Sealants, Adhesives
Fibres in Concrete
• Asbestos
• Carbon
• Aramid
• Glass
• Polypropylene
• Polyamide
• Polyester
• Nylon
• Rayon
• Polyvinyl alcohol
• Polyacrylonitrile
• Polyethylene
• Polyethylene pulp (oriented)
• Highly oriented polyethylene
• Rockwool
• Carbon steel
• Stainless steel
• Alkali-resistant glass
Concrete Containing Polymers
• Polymer Concrete
– Polymerising a mixture of monomer and aggregates.
• Latex Modified concrete
– Replacing a part of mixing water with latex
• Polymer Impregnated concrete
– Impregnating hardened concrete with a monomer and Polymerising the same in situ.
Ready Mixed Concrete
• The best way to improve the quality of concrete
• Currently only 15% of concrete is through Batching Plants &RMC
• In advanced countries this figure is around 85%
• Certification of the plants is an immediate need to sustain quality of the RMC industry
Pier ready for concreting
A panoramic view of Piers
General View
Advances in Concrete Technology Structural lightweight concrete
Heavy Weight concrete
High Strength Concrete
High Performance Concrete
Fibre Reinforced Concrete
Self Compacting concrete
Roller Compacted concrete
Concrete Containing Polymer
Decorative Concrete
Porous Concrete
High Performance Concrete
• ACI Definition
– Concrete meeting special combinations of performance and uniformity requirements that cannot always be achieved routinely using conventional constituents and normal mixing placing and curing practices
High Performance Concrete
High Impermeability
• Coefficient of permeability:
• less than 1x10-14 m/sec
High Strength
• Greater than 60 Mpa.
High Elastic Modulus
Low thermal Strain
Low drying shrinkage
Low Creep
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Self Compacting Concrete
Normal Concrete and High Performance Concrete Require Vibration for
Placement and Compaction
Where as
Self Compacting Concrete(SCC) Requires
No Vibration
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Mock-up Pier for
“Signature Bridge Project”
Pier Reinforcement
Heavy Congestion of Steel
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SCC : The Definition
A Concrete which flows : – Under Self Weight
– Without Segregation,
– Maintain Homogeneity
– Require No Vibration for Compaction
– Flow through Angular or Curved and Congested sections.
– A
– B
Benefits Faster construction
Reduction in site manpower
Better surface finish
Easier placing
Improved durability
Greater freedom in design
Thinner concrete sections
Reduced noise levels
absence of vibration
Safer working environment 65
Basic Ingredients :
• Cement
• Fine Aggregates (Sand)
• Coarse Aggregates
• Mineral Admixture : • Flyash,
• Silica Fume
• Chemical Admixtures : • Super Plasticizer,
• VMA
• Water
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High Volume Fly Ash Concrete
• Typical values
• Minimum 50% to 60% Fly Ash
• Low water content say less than 130 Kg/m3
• Very low dosage of dosage of Super plasticiser
Typical Examples of HVFAC
• Kauai Temple, Hawai 21MPa
• BAPS Temple, Houston Texas 28 Mpa
• C. Barker Hall, Berkeley, California, USA 39 MPa
• Note: These are 28 days values which will increase further with age.
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Concrete Porous Pavements? • Perhaps the greenest concrete product in the world is a new
porous low fines concrete that is being made using recycled aggregate and with Eco-Cements that set by absorbing CO2
Decorate concrete
• Decorative concrete is the use of concrete as not simply a utilitarian medium for construction but as an aesthetic enhancement to a structure, while still serving its function as an integral part of the structure itself such as floors, walls, driveways and patios
TYPES Stamped Concrete
Concrete Dyes
Acid Staining
Water based Staining
Overlaying
• Polymer Cement Overlays
• Stamped Overlays
Epoxy Coating
Polishing
Engraving
Form Liner
Decorative Concrete
Future The centre of development was:
• 10,000 years ago somewhere east and south of Mediterranean
• 2000 years ago was in Rome
• 1000 years ago information is hidden in religious texts
• 200 years ago was in England
• 100 years ago among Europe and the US
• The future is expected to be in Asia among Japan, China and India
– China is currently number 1 in Cement production and
– India is number 2 in the game.
Conclusions
• Concrete is very ‘old’ and a ‘new’ material.
• The developments will continue to make the concrete as useful as it always have been.
• Concrete will play a major role in improving the quality of life of the people in the years to come.
• Its contribution will continue to be significant in the social development of the humankind.
Thank You!!!