Pervious Pavement

1
Pervious Pavement
We can't solve problems by using the same kind
of thinking we used when we created them." Albert
Einstein. Pervious Pavements are a different way
of thinking about roads.
John Harrison, B.Sc. B.Ec. FCPA
2
What Is Pervious Pavement?

• Pervious pavement is a permeable pavement surface
  with a stone reservoir underneath.
• The reservoir temporarily stores surface runoff
  before infiltrating it into the subsoil or
  sub-surface drainage and in the process improves
  the water quality.
• Permeable materials such as ancient lime mortars
  and pervious pavements are made using relatively
  mono graded materials.
• Pervious pavements allow the earth to breathe,
  take in water and be healthy. The stone and soil
  under them acts as a reservoir and cleans the
  water just like the filter on a fish tank.
• Pervious pavements are safer to drive on as they
  do not develop "puddles", have a good surface to
  grip
• Subdivisions made with pervious pavement that
  also have street trees can be several degrees
  cooler than surrounding suburbs without.

3
The Water Cycle
The water or hydrological cycle is powered by the
sun and water changes state and is stored as it
moves through it.
Human intervention is reducing the time it takes
for water to return to the oceans resulting in
less moisture on land, salinity and aridity.
SourceIllustration by John M. Evans USGS,
Colorado District (http//ga.water.usgs.gov/edu/wa
tercyclegraphichi.html)
4
Australia Before Settlement
In years gone by grassland and forest covered the
land
5
Our Legacy

• In years gone by forests and grassland covered
  most of our planet.
• When it rained much of the water naturally
  percolated though soils that performed vital
  functions of
• slowing down the rate of transport to rivers and
  streams,
• purifying the water and
• replenishing natural aquifers.
• Our legacy has been to pave this natural bio
  filter, redirecting the water that fell as rain
  as quickly as possible to the sea.
• Given global water shortages, problems with
  salinity, pollution, volume and rate of flow of
  runoff we need to change our practices so as to
  mimic the way it was for so many millions of
  years before we started making so many changes.
• The key to survival in the future will be
  learning from nature and mimicking her subtle
  processes. Road are the arteries, veins and
  lymphatic system to cities.
• This presentation focuses on where we have gone
  wrong with roads and the radical TecEco
  Permecocrete solution.

6
Australia with a Little Lateral Thinking Effort
TecEco technology provides ways ofsequestering
carbon dioxide and utilising wastes to create our
techno - world
Less paper. Other Cl free processes - no
salinity
Evolution away from using trees paperless office
Vehicles more efficient and using fuel cells
Organic farming Carbon returned to soils.
Pervious pavements prevent immediate and polluted
run-off. Carbon dioxide and other gases absorbed
by TecEco Eco- Cements. Sewerage converted to
fertilizer and returned to soils. Buildings
generate own energy etc.
It is essential we learn to live with nature and
change our ways
7
One Planet, Many People, Many Interconnected
Problems
Global Sustainability Alliance Partners are in
the BIGGEST Business on the Planet Economic
Solutions to our Energy, Global Warming, Water
and Waste Problems.
8
Global Fresh Water

• A finite resource
• Population rising
• Per capita use rising
• Water-stress
• 1/3 world's population
• By 2025, 2/3 due to global warming.
• 1 person in 5 do not have access to safe drinking
  water
• Yet water is the most common substance on the
  planet.
• Water covers 70 of the surface
• Only 1 is potable

9
Australias Water Problems

• Australia is the driest inhabited continent in
  the world - only Antarctica gets less rain.
• Most of Australia has experienced drought under
  El Nino conditions for the past few years.
• Some major cities are seriously short of water.
• Yet giga litres of stormwater go into our coastal
  water ways every year carrying with it
  significant levels of pollution.

10
Stormwater Rainwater Pollution

• Pollution comes from many different sources,
  however the two main sources are Point and
  Non-point sources.
• Stormwater is the major cause of reduction in
  water quality in rivers and the destruction of
  marine environments.
• Stormwater is NOT supposed to include sewerage!
• Pollution is why it is not a good idea to eat too
  many fish from many areas near cities

Why mix rainwater and pollution?
11
Point and Non-Point Source Pollution

• Point Source PollutionPoint source pollution is
  when high levels of pollution enter a water
  system such as a wetland or river from one
  source, such as a factory, mine, sewage plant or
  garbage dump. Point source pollution is easy to
  trace.
• Non-Point Source PollutionNon-point source
  pollution is when levels of pollution enter a
  water system at various points and from various
  sources. This type of pollution is the most
  difficult to monitor and manage. The most common
  non-point source of stormwater pollution comes
  from local residents throughout a catchment.

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Stormwater Rainwater Pollution
Source thesource.melbournewater.com.au/.../river.
htm
13
Sources and Types of Pollution
Adapted from www.cwmb.sa.gov.au/kwc/section1/1-24
.htm
14
Types of Pollution (1)
Modified from EPA stormwater code of practice
from www.cwmb.sa.gov.au/kwc/section1/1-24.htm
15
Types of Pollution (2)
Modified from EPA stormwater code of practice
from www.cwmb.sa.gov.au/kwc/section1/1-24.htm
16
Roads Interrupt Natural Drainage

• We have dissected the landscape with roads and no
  matter what kind, they modify the drainage
  network.
• Roads themselves are impervious and also capture
  water.
• Stormwater from buildings and from properties
  usually goes to the same drainage system.
• Stormwater Rainwater Pollution

Various sources!
Source Keith Stichler, CBF
17
Roads are the Drainage Network
And represent a huge wasted catchment
18
Impervious Watersheds Kill Rivers and Speed up
the Water Cycle

• There is a relationship between the amount of
  impervious surface cover within a watershed and
  the quality of surface water within that
  watershed.
• 10 to 15 of an area is covered by impervious
  surfaces, the increased sediment and chemical
  pollutants in runoff have a measurable effect on
  water quality.
• 15 to 25 of a watershed is paved or impervious
  to drainage, increased runoff leads to reduced
  oxygen levels and harms stream life.
• If more than 25 of surfaces are paved, many
  types of macro and micro organisms in streams die
  from concentrated runoff and sediments

Smith, A. (2001). New Satellite Maps Provide
Planners Improved Urban Sprawl Insight, NASA
Goddard Space Flight Center, GSFC on-line News
Releases.
The more impervious the surface the more speed,
volume and pollution water acquires.
19
Purifying Water

• Pervious pavements filter water falling on them
  releasing it slowly to sub-surface drains or
  aquifers and finally the sea. There is little or
  now surface run-off to carry rubbish into drains
  and streams.
• Water quality is purified by the sub-pavement
  acting as a giant biofiliter allowing bacteria
  and oxygen to do their work and because surface
  rubbish does not contaminate it. 

20
Pervious Pavements Act Like a Giant Biofilter

• Just as fish cannot be kept in an aquarium
  without a filter system they are not healthy in
  our lakes dams creeks and rivers without natural
  or man made filtration of run off water.
• Pervious pavements and their sub structures act
  as a giant biofilters
• Pervious pavement with integral bacteria improves
  water quality entering aquifers, streams and
  rivers.
• The critical "first flush" of pollutants is sent
  rapidly into the cross-section where constantly
  available sources of bacteria and microbes exist
  and have sufficient air exchange capability to
  maintain themselves and perform their cleaning
  functions.

Source Wikipedia. Filtration system in a typical
aquarium (1) Intake. (2) Mechanical filtration.
(3) Chemical filtration. (4) Biological
filtration medium. (5) Outflow to tank.
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Speed, Volume Sediment Load and Pollution
Rainwater does good all the way to the sea.
Polluted and salty water do no good at all
Higher speed, higher volume, more energy, greater
distance covered more pollution and salts
Low speed, low volume low distance covered low
pollution and salts
The Water Dynamic
22
Traps Do Not Stop Micro and Molecular Pollution
Source www.dpiw.tas.gov.au/.../RPIO-4YJ3KA?open
Traps are useless for stopping most pollutants
other than those that are unsightly
www.azstorm.org/public_edu.php
23
The Functions of Roads

• Roads are the veins, arteries and lymphatic
  system of cities.
• They provide
• The network for
• The transport of resources and wastes
• Drainage
• The route for all services
• Water
• Sewerage
• Electricity
• Gas
• Telephone etc.
• Many different people are involved

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Current Road Designs are Not Sustainable
Traffic Engineers
Drainage and Traffic Engineers
Sewerage Engineers
Management
Hydraulic Engineers
Environmental Scientists
Gas Engineers
Ratepayers
Electrical Engineers
Telecommunication Engineers
Geo Technical Engineers
How often do you see the same section of road dug
up repeatedly in quick succession?
The various groups with an interest in roads do
not work together holistically
25
Changing the Road Paradigm

• Roads and associated services as they are today
  have not been thought out. They have evolved.
• In the past the agencies that are responsible for
  these networks and services have more or less
  acted independently of each other resulting in
• Wasted Resources
• Additional Cost
• How often do you see different crews digging up
  the same bit of road?
• This is not sustainable!

You never change things by fighting the existing
reality. To change something, build a new model
that makes the existing model obsolete.
Buckminster Fuller
26
Building a New Model

• The engineering paradigm too prevalent amongst
  the road building fraternity is
• Roads are for vehicles water on roads in
  dangerous collect it and get rid of it as
  quickly as possible
• Given the current water crisis can this limited
  thinking be allowed to continue?
• Only a small of water reticulated through a
  community is used for drinking.
• Most is used for washing, laundry, flushing
  toilets or watering gardens.
• Perhaps the water caught by our road drainage
  systems could be used?

27
Heads First for Action

• Water, CO2, waste and many other issues are
  mostly in our heads.
• We must first think differently then
• Act differently!
• Roads are not just for traffic
• They set drainage patterns
• Carry services under them
• Define wildlife zones
• Prevent natural percolation to aquifers etc.
• Roads in the future will have to be
• Holistically designed
• Take into account previously unintended outcomes
  such as local drainage alteration and pollution.
• Capture desperately needed water
• Our model, measure and mentor for change must be
  nature.

John Harrison with pervious pavement.
Photographer Peter Boyer
28
Our Guide - Biomimicry - Geomimicry

• 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.
• Geomimicry is similar to biomimicry but models
  geological rather than biological processes.

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 and very little of
energy. Geomimicry is a natural extension of
biomimicry and applies to geological rather than
living processes
We can learn from nature about how we should
construct roads
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Pervious Concrete Pavement - Addressing the Issues
Pervious pavement is a unique and effective means
of addressing environmental issues
Image source http//www.perviouspavement.org/
30
TecEco Permecocrete - Thinking About Water and
Roads
Pavements are not just for vehicles. They must do
much more
Cooling Evaporation
Sequestration
Moisture retention
Cleansing microbial activity and oxygenation
The substrate must be properly designed
Optional groundwater recharge
Optional impervious layer, underground drainage
and storage. Dual water supply or parks etc. only.
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Holistic Roads for the Future
In Australia we run many duplicate services down
each side of a road. Given the high cost of
installing infrastructure it would be smarter to
adopt a system whereby services run down the
middle of a road down what amount to giant box
culverts.
Conventional bitumen or concrete footpath pavement
Pervious Eco-Cement concrete pavement
(Permecocrete) surface using recycled aggregates
Pervious gravel under for collection, cleansing
and storage of water
Services to either side of the road. All in same
trench of conduit
Service conduit down middle of road
Foamed Eco-Cement concrete root redirectors and
pavement protectors. Roots will grow away from
the foamed concrete because of its general
alkalinity. It will also give to some extent
preventing surface pavement cracking.
Collection drains to transport drain or pipe in
service conduit at intervals
Impermeable layer (concrete or plastic liner)
angling for main flow towards collection drains
Possible leakage to street trees and underground
aquifers
Its time for a road re think!
32
TecEco Eco-Cement Permecocrete - Mimicking Nature

• Permecocrete is made with Eco-Cements that set by
  absorbing CO2 and can use recycled aggregates. It
  does not get any greener!
• Freedom from water restrictions forever!
• Pure fresh water from your own block.
• Filtration through Permecocrete and water feature
  in garden will keep water pure and fresh.
• Cooler house and garden (cycle under slab for
  house cooling/heating option).
• Lower infrastructure costs for local council.

Water featurekeeps water clean
All rainwater redirected to pavement filter.
Permecocrete pervious pavement
Pump
Water storage e.g. under drive
33
Placing Pervious Pavement
Source www.percocrete.com
34
Finishing Pervious Pavement
Source www.percocrete.com
35
Laying Pervious Pavement
Source www.percocrete.com
36
Cross Section Pervious Pavement
Source www.percocrete.com
37
TecEco Permecocrete

• TecEco Eco-Cement Permecocrete concrete pavement
  technology
• Is a unique and effective means to address
  important environmental issues and support
  sustainable growth.
• Environmental Advantages
• Slows down the rate of transport to rivers and
  streams
• purifying water
• replenishing natural aquifers.
• Reducing salinity
• Eco-Cement Pervious concrete sequesters carbon
  dioxide
• Non Environmental Advantages
• Safer for traffic
• Improved acoustic properties
• Reduces building maintenance
• Cooler suburbs
• Reduced drainage infrastructure costs
• Reduces the need for culverts, pies drains,
  retention ponds, swales, and other storm water
  management devices.
• Less watering of street trees

38
Environmental Advantages

• Reduced volume and rate of runoff
• Pervious pavement would allow the replenishment
  of aquifers and reduced the cost of
  infrastructure to carry water out to sea as the
  volume and rate of flow would be less. Not as
  many pollutants, rubbish and debris would be
  transported reducing waterway pollution.
• Cleaner water - less pollution
• A pervious pavement with integral bacteria would
  improve water quality entering aquifers, streams
  and rivers. The critical "first flush" of
  pollutants would be sent rapidly into the
  cross-section where constantly available sources
  of bacteria and microbes exist and have
  sufficient air exchange capability to maintain
  themselves and perform their cleaning functions.
  Pervious pavements could act as both pavements
  and bio-filters at the same time.
• Replenish aquifers or provide water
• Reducing salinity by replenishment with fresh
  water.
• Permecocretes are also carbon sinks.

39
Non Environmental Advantages

• Pervious pavements do not collect puddles of
  water making it safer for traffic
• Pervious pavements are quieter as the absorb
  sound
• Pervious pavement prevent the ground drying out
  under building cracking them.
• Pervious pavements made with TecEco Eco-Cements
  are more durable
• Cities with pervious pavement are cooler
• They can transpire naturally (loosing latent heat
  of evaporation)
• Eco-Cement Permecocrete concrete pavement has a
  lighter albido
• Given economies of scale Tec-Eco Permecocrete
  pavement should cost less
• Less infrastructure
• Reduced need for culverts, pipes, retention
  ponds, swales, and other stormwater management
  devices

40
Hot City Syndrome and Pervious Pavement

• Ever walked up a pebble beach on a hot sunny day?
  The heat held by the stones can be unbearable!
  Its the same in large cities. There are so many
  materials with high specific heat that during hot
  sunny weather and with no natural transpiration,
  due to the fact that we have paved all the
  ground, large cities just get hotter and hotter.
• As architects, engineers and designers of cities
  we need to come to grips with the macro impacts
  of the materials we use. Hot city syndrome is one
  of a number of man made phenomena that the use of
  pervious Eco-Cement pavements will reduce. The
  solution is to let the ground breathe and
  pervious pavements do this. Evaporation after all
  is still the principle behind many cooling
  systems so why do we pave the ground and
  prevent moisture entering or exiting?

41
Solving the Water Problem
Collecting Rain Water Using Pervious Pavement

• An unknown but huge quantity of water is drained
  away to sea taking with it polluting substances
  and articles every time it rains on our cities.
• This rapid drainage of rain requires a high cost
  of investment in much larger drains than the
  original natural drainage replaced because water
  no longer percolates through natural vegetation
  and obstacles.
• In urban and some agricultural areas water gets
  to the sea in hours not days!
• This water could be collected by permeable roads
  also acting as giant bio filters, subterranean
  reservoirs (the city of Alexandria had huge
  underground cisterns over 2000 years ago) and
  collection and redistribution network.
• An essential component of this paradigm is
  pervious pavement.

42
The Clogging Myth - Cleaning Pervious Pavement
Those who remain sceptics please also note that
it is better to have pollution collected from a
pervious pavement by machinery than pollute our
coastal waterways
Frimokar Australia high pressure jet and suction
cleaning in action
The experience of many engineers is that with
relatively minor control and maintenance clogging
will not reduce the infiltration rate below a
design rate within the lifecycle of the pavement.
Like any other kind of surface, pervious
pavements should be cleaned periodically to
remove debris and water under pressure combined
with suction is most effective.
43
Making Pervious Pavement

• Ideally a pervious pavement should be made with
  mono-graded stone aggregates and a binder and be
  similar to asphalt or concrete to handle and
  install.
• In cold areas it is important that the pavement
  should not trap water otherwise in winter the
  water would freeze and cause cracking.
• It is also important to detail a permeable
  structural base and sub base for the pavement
  that has a high void ratio as this acts as a
  reservoir, and provide underground drainage as
  required.

Comparing Concrete Pervious Pavements to Asphalt
44
Salinity

• Increasing salinity is one of the most
  significant environmental problems facing
  Australia.
• While salt is naturally present in many of our
  landscapes, European farming practices which
  replaced native vegetation with shallow-rooted
  crops and pastures have caused a marked increase
  in the expression of salinity in our land and
  water resources.
• Rising groundwater levels, caused by these
  farming practices, are bringing with them
  dissolved salts which were stored in the ground
  for millennia.
• Salt is being transported to the root-zones of
  remnant vegetation, crops, pastures, and directly
  into our wetlands, streams and river systems. The
  rising water tables are also affecting our rural
  infrastructure including buildings, roads, pipes
  and underground cables.
• Salinity and rising water tables incur
  significant and costly impacts.
• According to the Australian National Action plan
  (http//www.napswq.gov.au/publications/salinity.ht
  mlhow) and CSIRO web sites there are two main
  causes of salinity
• irrigation salinity
• dryland salinity
• Caused by clearing
• Caused by evaporation

45
Irrigation Salinity

• According to the Australian National Action plan
  website at http//www.napswq.gov.au/publications/s
  alinity.html how salinity occurs through
  irrigation is because water soaks through the
  soil area where the plant roots grow, adding to
  the existing water. The additional irrigation
  water causes the underground water-table to rise,
  bringing salt to the surface. When the irrigated
  area dries and the underground water-table
  recedes, salt is left on the surface soil. Each
  time the area is irrigated this salinity process
  is repeated.
• The government website quoted above fails to
  state the obvious which is that
• Every time water percolates through rocks and
  soil it picks up more salts. In the Murray
  Darling system a lot of irrigation water returns
  on the surface and underground to the river and
  is used again for irrigation, exacerbating the
  problem
• The sequence forestry-agriculture-irrigation-salin
  ity-aridity has destroyed many civilisations
  will ours be next?

Figure from the Australian National Action plan
website at http//www.napswq.gov.au/publications/s
alinity.htmlhow
46
Dryland Salinity Caused by Clearing

• According to the Australian National Action plan
  website at http//www.napswq.gov.au/publications/s
  alinity.htmlhow Dryland salinity is caused when
  the rising water-table brings natural salts in
  the soil to the surface.
• The salt remains in the soil and becomes
  progressively concentrated as the water
  evaporates or is used by plants.
• One of the main causes for rising water-tables is
  the removal of deep rooted plants, perennial
  trees, shrubs and grasses and their replacement
  by annual crops and pastures that do not use as
  much water.

Figures from the Australian National Action plan
website at http//www.napswq.gov.au/publications/s
alinity.htmlhow
47
Dryland Salinity Caused by Evaporation

• Salinity also also develops as excess water moves
  to and collects in poorly drained discharge
  zones. The buildup of excess water brings
  dissolved salts to the surface where evaporation
  concentrates them.

Figure modified from the Manitoba Agriculture Web
Site www.gov.mb.ca/.../soilwater/soil/fbe01s06.htm
l
48
Salinity, Agricultural Practices and Pervious
Pavement
Native tree belts
Deep rooted salt tolerent species (The PundaZoie
company)
Salinity in untreated areas
TecEco permecocrete roads
Salinity in untreated areas
Contoured swales
Deep drains
Fresh water
Salty water

• Salinity can be rectified by a combination of
• Deep drainage.
• Mulching to increase humidity at ground level and
  reduce evaporative loss.
• Planting deep rooted salt tolerant species and
  leaving native belts that reduce the overall rate
  of evapotranspiration of the fresh water lens on
  top of ground water.
• Pervious rather than sealed surfaces (TecEco
  permecocrete pervious pavement).
• Allowing capture of fresh water rather than run
  off.
• Maximising capture and use of fresh water and
  minimising irrigation water.
• Replenishing aquifers with fresh rain water
  rather than recycled water through irrigation.

49
How Our Theories Differ on Salinity

• Many websites including the CSIRO and Australian
  government website on salinity when discussing
  salinity that is not clearly related to
  irrigation and the re-use of water seem to think
  that the problem relates to reduced
  evapotranspiration with agriculture and rising
  water tables that bring ancient salts to the
  surface.
• We think this analysis wrong. When land is
  cleared natural mulches and soil humus that
  retain water and reduce evaporation and rate of
  run off at the surface of soils are removed.
• As a consequence what then happens is that fresh
  water does not enter the water table when it
  rains. It runs off into our rivers. According to
  the water dynamic discussed above it also picks
  up salt and pollution. Gradually during dry
  periods the fresh water lens on top of our
  aquifers is used up and the saltier water
  underneath remains.
• Reused irrigation water brings with it the salt
  it has picked up along the way.

50
TecEco Eco-Cement Pervious Pavement
Permecocrete
Allow many mega litres of good fresh water to
become contaminated by the pollutants on our
streets and pollute coastal waterways
Permecocrete
Or
Capture and cleanse the water for our use?
TecEco have now perfected pervious pavements that
can be made out of mono-graded recycled
aggregates and other wastes and that sequester
CO2.
51
Cities as Profitable Carbon Sinks?

• THERE is a way to make our city streets as green
  as the Amazon rainforest. Almost every aspect of
  the built environment, from bridges to factories
  to tower blocks, and from roads to sea walls,
  could be turned into structures that soak up
  carbon dioxide- the main greenhouse gas behind
  global warming. All we need to do is change the
  way we make cement. Pearce, F. (2002). "Green
  Foundations." New Scientist 175(2351) 39-40.

52
We Must Learn to Recycle Everything Including CO2

• 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 calcium and magnesium
  carbonate materials and other wastes in pervious
  pavement mimics nature.

We all use carbon and wastes to make our homes!
In eco-cement blocks and mortars the binder is
carbonate and the aggregates are preferably
wastes Biomimicry - Geomimicry
53
Geomimicry

• There are 1.2-3 grams of magnesium and about .4
  grams of calcium in every litre of seawater.
• There is enough calcium and magnesium in seawater
  with replenishment to last billions of years at
  current needs for sequestration.
• To survive we must build our homes like these
  seashells using CO2 and alkali metal cations.
  This is geomimicry

• Carbonate sediments such as these cliffs
  represent billionsof years of sequestrationand
  cover 7 of the crust.

54
Geomimicry for Planetary Engineers?

• Large tonnages of carbon were put away during
  earths geological history as limestone,
  dolomite, magnesite, coal and oil by the activity
  of plants and animals.
• Shellfish built shells from it and
• Trees turned it into wood.
• These same plants and animals wasted nothing
• The waste from one was the food or home for
  another.
• Because of the colossal size of the flows
  involved the answer to the problems of greenhouse
  gas and waste is to use them both in building
  materials.

Materials are very important
55
Geomimicry for Planetary Engineers?

• Such a paradigm shift in resource usage will not
  occur because it is the right thing to do.
• It can only happen economically.
• We must put an economic value on carbon to solve
  global warming by
• Inventing new technical paradigms such as offered
  by the Global Sustainability Alliance in Gaia
  Engineering.
• Evolving culturally to effectively use these
  technical paradigms
• By using carbon dioxide and other wastes as a
  building materials we could economically reduce
  their concentration in the global commons.

Materials are very important
56
Economically Driven Sustainability
New, more profitable technical paradigms are
required that result in more sustainable and
usually more efficient moleconomic flows that
mimic natural flows or better, reverse our
damaging flows.
- ECONOMICS -
Change is only possible economically. It will not
happen because it is necessary or right.
57
Changing the Technology Paradigm
It is not so much a matter of dematerialisation
as a question of changing the underlying
moleconomic flows. We need materials that require
less energy to make them, do not pollute the
environment with CO2 and other releases, last
much longer and that contribute properties that
reduce lifetime energies. The key is to change
the technology paradigms

• By enabling us to make productive use of
  particular raw materials, technology determines
  what constitutes a physical resource1
• Pilzer, Paul Zane, Unlimited Wealth, The Theory
  and Practice of Economic Alchemy, Crown
  Publishers Inc. New York.1990

58
Cultural Change

• Al Gore (SOS)
• CSIRO reports
• STERN Report
• Lots of Talkfest
• IPCC Report
• Branson Prize
• Live Earth (07/07/07)

The media have a growing role
59
Sustainability is Where Culture and Technology
Meet
Increase in demand/price ratio for greater
sustainability due to cultural change.

Supply
Equilibrium Shift
Greater Value/for impact (Sustainability) and
economic growth
ECONOMICS
We must rapidly move both the supply and demand
curves for sustainability
Demand
Increase in supply/price ratio for more
sustainable products due to technical innovation.

A measure of the degree of sustainability of an
industrial ecology is where the demand for more
sustainable technologies is met by their supply.
60
Making Carbonate Building Materials to Solve the
Global Warming Problem

• How much magnesium carbonate would have to be
  deposited to solve the problem of global warming?
• 12 billion tonnes CO2 22.99 billion tonnes
  magnesite
• The density of magnesite is 3 gm/cm3 or 3
  tonne/metre3
• Thus 22.9/3 billion cubic metres 7.63 cubic
  kilometres of magnesite are required to be
  deposited each year.
• Compared to the over seven cubic kilometres of
  concrete we make every year, the problem of
  global warming looks surmountable.
• If magnesite was our building material of choice
  and we could make it without releases as is the
  case with Gaia Engineering, we have the problem
  as good as solved!

We must build with carbonate and waste
Gaia Engineering offers technical paradigms
allowing us to do so economically
61
Huge Potential for Sequestration and Waste
Utilisation in the Built Environment

• Reducing the impact of the take and waste phases
  of the techno-process by.
• including carbon in materialsthey are
  potentially carbon sinks.
• including wastes forphysical properties aswell
  as chemical compositionthey become resources.
• re engineering materials toreduce the lifetime
  energyof buildings
• A durable low pH high bondingbinder system is
  requiredfor effective waste utilisationsuch as
  TecEco Tec andEco-Cements

Many wastes including CO2 can contribute to
physical properties reducing lifetime energies
CO2
CO2
CO2
C
CO2
Waste
Pervious pavement
62
Gaia Engineering Flowchart
Portland CementManufacture
CaO
TecEcoTec-Kiln
Industrial CO2
MgO
Clays
Fresh Water
TecEcoCementManufacture
MgCO3 and CaCO3Stone
Brine or Seawater
Extraction
Eco-Cements
WasteAcid or Bitterns
Tec-Cements
Valuable Commodity Salts or hydrochloric acid.
Buildingcomponents aggregates
Extraction inputs and outputs depending on method
chosen
Other waste
Built Environment
Building waste
63
The Gaia Engineering Tececology
The Gaia Engineering tececology could be thought
of as an open technical ecology designed to
reverse major damaging moleconomic and other
system flows outside the tececology
Industrial Ecologies are generally thought of as
closed loop systems with minimal or low impacts
outside the ecology
The Gaia Engineering tececology is not closed and
is designed to reverse damaging moleconomic flows
outside the ecology - LIKE A GIANT ECOLOGICAL PUMP
64
The Gaia Engineering Process
Gaia Engineering delivers profitable outcomes
whilst reversing underlying undesirable
moleconomic flows from other less sustainable
techno-processes outside the tececology.
Inputs Atmospheric or industrial CO2,brines,
waste acid or bitterns, other wastes Outputs Carb
onate building materials, potable water, valuable
commodity salts.
Carbonate building components
Solar or solar derived energy
TecEcoKiln
TecEco MgCO2 Cycle
MgO
Eco-Cement
MgCO3
Extraction Process
1.29 gm/l Mg.412 gm/l Ca
Coal
Fossil fuels
Carbon or carbon compoundsMagnesium compounds
Oil
65
TecEco Cements
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.
66
TecEco Formulations

• Tec-cements (5-15 MgO, 85-95 OPC)
• 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 voidspaste
  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 (15-95 MgO, 85-5 OPC)
• contain more reactive magnesia than in
  tec-cements. Brucite in permeable materials
  carbonates forming stronger fibrous mineral
  carbonates and therefore presenting huge
  opportunities for waste utilisation and
  sequestration.
• Enviro-cements (5-15 MgO, 85-95 OPC)
• contain similar ratios of MgO and OPC to
  eco-cements but in non permeable 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.

67
Tec Eco-Cement Theory

• Many Engineering Issues are Actually
  Mineralogical Issues
• Problems with Portland cement concretes are
  usually resolved by the band aid engineering
  fixes. e.g.
• Use of calcium nitrite, silanes, cathodic
  protection or stainless steel to prevent
  corrosion.
• Use of coatings to prevent carbonation.
• Crack control joins to mitigate the affects of
  shrinkage cracking.
• Plasticisers to improve workability.
• Portlandite and water are the weakness of
  concrete
• TecEco remove Portlandite it and replacing it
  with magnesia which hydrates to Brucite.
• The hydration of magnesia consumes significant
  water

68
Tec Eco-Cement Theory

• Portlandite (Ca(OH)2) is too soluble, mobile and
  reactive.
• It carbonates, reacts with Cl- and SO4- 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 significant water and
  concentrating alkalis forming Brucite which is
  another alkali, but much less soluble, mobile or
  reactive than Portlandite.
• In Eco-Cements brucite carbonates forming
  hydrated compounds with greater volume

69
Why Add Reactive Magnesia?

• To maintain the long term stability of CSH.
• Maintains alkalinity preventing the reduction in
  Ca/Si ratio.
• To remove water.
• Reactive magnesia consumes water as it hydrates
  to possibly hydrated forms of Brucite.
• To raise the early Ph.
• Increasing non hydraulic strength giving
  reactions
• To reduce shrinkage.
• The consequences of putting brucite through the
  matrix of a concrete in the first place need to
  be considered.
• To make concretes more durable
• Because significant quantities of carbonates are
  produced in permeable substrates which are
  affective binders.

Reactive MgO is a new tool to be understood with
profound affects on most properties
70
Why do Eco-Cements use Magnesium Compounds?

• At 2.09 of the crust magnesium is the 8th most
  abundant element.
• Magnesium oxide is easy to make using non fossil
  fuel energy and efficiently absorbs CO2
• Because magnesium has a low molecular weight,
  proportionally a much greater amount of CO2 is
  released or captured.
• A high proportion of water in the binder means
  that a little binder goes a long way

71
Strength with Blend Porosity
Tec-cement concretes
Eco-cement concretes
High Porosity
Enviro-cement concretes
High OPC
High Magnesia
STRENGTH ON ARBITARY SCALE 1-100
72
Solving Waste Logistics Problems

• TecEco cementitious composites represent a cost
  affective option for
• using non traditional aggregates from on site
  reducing transports costs and emissions
• use and immobilisation of waste.
• Because they have
• lower reactivity
• less water
• lower pH
• Reduced solubility of heavy metals
• less mobile salts
• greater durability.
• denser.
• impermeable (tec-cements).
• dimensionally more stable with less shrinkage and
  cracking.
• homogenous.
• no bleed water.

TecEco Technology - Converting Waste to Resource
73
Eco-Cements

• Eco-cements are similar but potentially superior
  to lime mortars because
• The calcination phase of the magnesium
  thermodynamic cycle takes place at a much lower
  temperature and is therefore more efficient.
• Magnesium minerals are generally more fibrous and
  acicular than calcium minerals and hence add
  microstructural strength.
• Water forms part of the binder minerals that
  forming making the cement component go further.
  In terms of binder produced for starting material
  in cement, eco-cements are much more efficient.
• Magnesium hydroxide in particular and to some
  extent the carbonates are less reactive and
  mobile and thus much more durable.

74
Eco-Cements

• Have high proportions of reactive magnesium oxide
• Carbonate like lime
• Generally used in a 15-112 paste basis because
  much more carbonate binder is produced than
  with lime
• MgO H2O ltgt Mg(OH)2
• Mg(OH)2 CO2 H2O ltgt MgCO3.3H2O
• 58.31 44.01 ltgt 138.32 molar mass (at least!)
• 24.29 gas ltgt 74.77 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 CO2 and water
As Fred Pearce reported in New Scientist Magazine
(Pearce, F., 2002), There is a way to make our
city streets as green as the Amazon rainforest.
75
Carbonation is Proportional to Porosity
CarbonationRate
Macro Porosity
76
Carbonation is Proportional to Time
100
Carbonation
Time
180 days
77
CO2 Abatement in Eco-Cements
No Capture11.25 mass reactive magnesia, 3.75
mass Portland cement, 85 mass
aggregate. Emissions.37 tonnes to the tonne.
After carbonation. approximately .241 tonne to
the tonne.
Portland Cements15 mass Portland cement, 85
mass aggregate Emissions.32 tonnes to the
tonne. After carbonation. Approximately .299
tonne to the tonne.
Capture CO211.25 mass reactive magnesia, 3.75
mass Portland cement, 85 mass
aggregate. Emissions.25 tonnes to the tonne.
After carbonation. approximately .140 tonne to
the tonne.
Capture CO2. Fly and Bottom Ash11.25 mass
reactive magnesia, 3.75 mass Portland cement, 85
mass aggregate. Emissions.126 tonnes to the
tonne. After carbonation. Approximately .113
tonne to the tonne.
For 85 wt Aggregates 15 wt Cement
Eco-cements in permeable products absorb carbon
dioxide from the atmosphere. Brucite carbonates
forming lansfordite, nesquehonite and an
amorphous phase, completing the thermodynamic
cycle.
Greater Sustainability
.299 gt .241 gt.140 gt.113Bricks, blocks, pavers,
mortars and pavement made using eco-cement, fly
and bottom ash (with capture of CO2 during
manufacture of reactive magnesia) have 2.65 times
less emissions than if they were made with
Portland cement.
78
Eco-Cement Strength Development

• Eco-cements gain early strength from the
  hydration of PC.
• Later strength comes from the carbonation of
  brucite forming an amorphous phase, lansfordite
  and nesquehonite.
• Strength gain in eco-cements is mainly
  microstructural because of
• More ideal particle packing (Brucite particles at
  4-5 micron are under half the size of cement
  grains.)
• The natural fibrous and acicular shape of
  magnesium carbonate minerals which tend to lock
  together.
• More binder is formed than with calcium
• Total volumetric expansion from magnesium oxide
  to lansfordite is for example volume 811.

79
Eco-Cement Strength Gain Curve
Eco-cement bricks, blocks, pavers and mortars
etc. take a while to come to the same or greater
strength than OPC formulations but are stronger
than lime based formulations.
80
Chemistry of Eco-Cements

• There are a number of carbonates of magnesium.
  The main ones appear to be an amorphous phase,
  lansfordite and nesquehonite.
• The carbonation of magnesium hydroxide does not
  proceed as readily as that of calcium hydroxide.
• ?Gor Brucite to nesquehonite - 38.73 kJ.mol-1
• Compare to ?Gor Portlandite to calcite -64.62
  kJ.mol-1
• The dehydration of nesquehonite to form magnesite
  is not favoured by simple thermodynamics but may
  occur in the long term under the right
  conditions.
• ?Gor nesquehonite to magnesite 8.56 kJ.mol-1
• But kinetically driven by desiccation during
  drying.
• Reactive magnesia can carbonate in dry conditions
  so keep bags sealed!
• For a full discussion of the thermodynamics see
  our technical documents.

TecEco technical documents on the web cover the
important aspects of carbonation.
81
Eco-Cement Reactions
82
Eco-Cement Micro-Structural Strength
83
Carbonation

• Eco-cement is based on blending reactive
  magnesium oxide with other hydraulic cements and
  then allowing the Brucite and Portlandite
  components to carbonate in permeable materials
  such as concretes blocks and mortars.
• Magnesium is a small lightweight atom and the
  carbonates that form contain proportionally a lot
  of CO2 and water and are stronger because of
  superior microstructure.
• The use of eco-cements for block manufacture,
  particularly in conjunction with the kiln also
  invented by TecEco (The Tec-Kiln) would result in
  sequestration on a massive scale.
• As Fred Pearce reported in New Scientist Magazine
  (Pearce, F., 2002), There is a way to make our
  city streets as green as the Amazon rainforest.

Ancient and modern carbonating lime mortars are
based on this principle
84
Aggregate Requirements for Carbonation

• The requirements for totally hydraulic limes and
  all hydraulic concretes is to minimise the amount
  of water for hydraulic strength and maximise
  compaction and for this purpose aggregates that
  require grading and relatively fine rounded sands
  to minimise voids are required
• For carbonating eco-cements and lime mortars on
  the on the hand the matrix must breathe i.e.
  they must be permeable
• requiring a coarse fraction to cause physical air
  voids and some vapour permeability.
• Coarse fractions are required in the aggregates
  used!

85
CO2 Abatement in Eco-Cements
No Capture11.25 mass reactive magnesia, 3.75
mass Portland cement, 85 mass
aggregate. Emissions.37 tonnes to the tonne.
After carbonation. approximately .241 tonne to
the tonne.
Portland Cements15 mass Portland cement, 85
mass aggregate Emissions.32 tonnes to the
tonne. After carbonation. Approximately .299
tonne to the tonne.
Capture CO211.25 mass reactive magnesia, 3.75
mass Portland cement, 85 mass
aggregate. Emissions.25 tonnes to the tonne.
After carbonation. approximately .140 tonne to
the tonne.
Capture CO2. Fly and Bottom Ash11.25 mass
reactive magnesia, 3.75 mass Portland cement, 85
mass aggregate. Emissions.126 tonnes to the
tonne. After carbonation. Approximately .113
tonne to the tonne.
For 85 wt Aggregates 15 wt Cement
Eco-cements in permeable products absorb carbon
dioxide from the atmosphere. Brucite carbonates
forming lansfordite, nesquehonite and an
amorphous phase, completing the thermodynamic
cycle.
Greater Sustainability
.299 gt .241 gt.140 gt.113Bricks, blocks, pavers,
mortars and pavement made using eco-cement, fly
and bottom ash (with capture of CO2 during
manufacture of reactive magnesia) have 2.65 times
less emissions than if they were made with
Portland cement.
86
TecEco Cement LCA
TecEco Concretes will have a big role post Kyoto
as they offer potential sequestration as well as
waste utilisation
The TecEco LCA model is available for download
under tools on the web site
87
Net Emissions/Sequestration Compared
(Gaia Engineering Assumed)
88
Rosendale Concretes Proof of Durability

• Rosendale cements contained 14 30 MgO
• A major structure built with Rosendale cements
  commenced in 1846 was Fort Jefferson near key
  west in Florida.
• Rosendale cements were recognized for their
  exceptional durability, even under severe
  exposure. At Fort Jefferson much of the 150
  year-old Rosendale cement mortar remains in
  excellent condition, in spite of the severe ocean
  exposure and over 100 years of neglect. Fort
  Jefferson is nearly a half mile in circumference
  and has a total lack of expansion joints, yet
  shows no signs of cracking or stress. The first
  phase of a major restoration is currently in
  progress.

More information from http//www.rosendalecement.n
et/rosendale_natural_cement_.html
89
A Post Carbon Age
We all use carbon and wastes!
90
Eco-Cement compared to Carbonating Lime Mortar.

• The underlying chemistry is very similar however
  eco-cements are potentially superior to lime
  mortars because
• The calcination phase of the magnesium
  thermodynamic cycle takes place at a much lower
  temperature
• Magnesium minerals are generally more fibrous and
  acicular than calcium minerals and hence a lot
  stronger.
• Water forms part of the binder minerals that
  forming making the cement component go further.
• Magnesium hydroxide in particular and to some
  extent the carbonates are less reactive and
  mobile and thus much more durable.
• A less reactive environment with a lower long
  term pH. (around 10.5 instead of 12.35)
• Because magnesium has a low molecular weight,
  proportionally a much greater amount of CO2 is
  captured.
• Carbonation in the built environment would result
  in significant sequestration because of the shear
  volumes involved.
• Carbonation adds considerable strength and some
  steel reinforced structural concrete could be
  replaced with fibre reinforced permeable
  carbonated concrete.

91
A More Sustainable Built Environment
CO2 H2O gtHydrocarbons compounds using bacteria
CO2
OTHERWASTES
PERMANENT SEQUESTRATION WASTE UTILISATION (Man
made carbonate rock incorporating wastes as a
building material) Paretos principle -80 of the
build environment in non structural and could be
carbonate from Greensols held together by
Eco-Cements
GREENSOLS
ECO-CEMENTCONCRETES
MgO
TECECO KILN
MAGNESIUM CARBONATE
RECYCLED BUILDING MATERIALS
There is a way to make our city streets as green
as the Amazon rainforest. Fred Pearce, New
Scientist Magazine
SUSTAINABLE CITIES
92
Conclusion

• Pervious pavements made with TecEco Eco-Cements
  would utilise a considerable proportion of wastes
  such as fly ash and as they would carbonate,
  provide substantial abatement. Water entering
  aquifers, streams and rivers would be of higher
  quality and carry less macro pollutants.
• Cities with pervious pavements would be safer for
  traffic, be cleaner and have less pollution
• Fresh water replenishment of aquifers would
  reduce salinity and reverse falling water tables.
• Pervious pavements could provide a means for
  water capture with in situ cleansing thereby
  solving the water crisis in our cities