pervious pavement

1Presentation downloadable from www.tececo.com

Pervious PavementPervious Pavement

“We can't solve problems by using the same kind of thinking we used when we created them." Pervious pavements are a different way of thinking about roads. Albert Einstein

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


What Is Pervious Pavement?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. Pervious materials such as ancient lime mortars and pervious pavements are made using relatively mono graded materials. In the case of pervious pavement this translates as a lack of "fine" materials. No fines concrete or under asphalted gravel are names for common materials used.

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. They are safer to drive on as they do not develop "puddles", have a good surface to grip and importantly, in Australia, some parts of the US and many other places in the world subdivisions made with pervious pavement that also have street trees can be several degrees cooler than surrounding suburbs without.


The Water CycleThe Water CycleThe 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.Source:Illustration by John M. Evans USGS, Colorado District (http://ga.water.usgs.gov/edu/watercyclegraphichi.html)


Australia Before SettlementAustralia Before Settlement

In years gone by grasslan

d and forest

covered the land


Australia NowAustralia Now

Paper Mill - Soda liquor + Cl

Forestry - Cover removal

Farming - Pesticide, N P K

Cows - methane

Vehicles - carbon dioxide

Immediate and polluted water run-off.Air pollution.Carbon dioxide and other gases.Putrescible wastes. Huge linkages.

Our impacts

on the environme

nt are many and damaging


Our LegacyOur 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 pervious Tec-Pavement solution.


Australia with a Little Lateral Thinking & EffortAustralia with a Little Lateral Thinking & Effort

Less paper. Other Cl free processes - no salinity

Evolution away from using trees – paperless office

Organic farming Carbon returned to soils.

Cows – CSIO anti methane bred

Vehicles – more efficient and using fuel cells

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.

TecEco technology provides ways ofsequestering carbon dioxide and utilising wastes to create our techno - world

It is essential we learn

to live with

nature and

change our ways


One Planet, Many People, Many Interconnected ProblemsOne 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.


Global Fresh WaterGlobal Fresh WaterA 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


Australia’s Water ProblemsAustralia’s 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.


Stormwater = Rainwater + PollutionStormwater = 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?


Point and Non-Point Source PollutionPoint 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.


Stormwater = Rainwater + PollutionStormwater = Rainwater + Pollution

Source: thesource.melbournewater.com.au/.../river.htm


Sources and Types of PollutionSources and Types of Pollution

Land uses Types of pollutionRural/agricultural &market

gardensSilt, pesticides, fertilisers, livestock faeces.

Residential properties & gardensDetergent, pesticides, fertiliser, dog faeces, leaf litter.

Industrial areas Industrial runoff & acidity

Roads & carparksOil, petrol, heavy metals, leaf litter

Shopping centresLitter, shopping bags, junk food containers

Service stations Detergents, oil, petrol

Construction/building sites Silt, paint, packaging, bricks

Sewage treatment plant Bacteria, phosphorus, nitrates

Parks and reservesLitter, dog and cat faeces, grass cuttings, leaves

Adapted from: www.cwmb.sa.gov.au/kwc/section1/1-24.htm


Types of Pollution (1)Types of Pollution (1)

Modified from:EPA stormwater code of practice from www.cwmb.sa.gov.au/kwc/section1/1-24.htm

Litter Pedestrians dropping food wrappers , cigarette butts etc. Motorists tossing litter from their vehicles. Litter from building sites. Industry packaging and other waste materials. Trucks with uncovered loads which blows onto roads.

Macro

Leaves Deciduous trees drop their leaves in Autumn creating a significant pollution problem in the waterways. Excessive leaves enter the stormwater system, choking waterways, reducing sunlight penetration and decomposing, causing nitrate pollution. This can create low oxygen conditions, killing animals.

MacroMicro and Molecular

Sediment Sediment is a major source of pollution in stormwater. Excessive sediment chokes creek beds and reduces flow capacity as well as de- grading natural ecosystems by stifling aquatic plants and animals and blocking sunlight. Sources include construction sites, erosion along streams and rivers, soil erosion from poor management of agricultural activities, and road runoff.

Micro

Soaps and detergents Detergent and soaps tend to contain high levels of phosphorus. This chemical is a limiting factor in plant growth. Excessive amounts provide the nutrients required to fuel an algal bloom.

Molecular


Types of Pollution (2)Types of Pollution (2)

Source:EPA stormwater code of practice from www.cwmb.sa.gov.au/kwc/section1/1-24.htm

Oil and grease Enter the stormwater system via leaking engines, deliberate dumping and accidental spills. High levels of oil can directly threaten the life of animals in waterways.

Macro and Molecular

Nutrients Enter the stormwater system via runoff from parks and farms that use fertiliser, effluent from sewage treatment plants and septic tanks, chemical and fertiliser spills, and rotting vegetation. Nutrients provide fuel for algal blooms which choke waterways, cut off light and hence kill off aquatic ecosystems. Excessive nitrogen is one of the major factors in the die back of seagrass in our rivers.

Molecular

Faecal coliforms Enter the stormwater system by contamination with human or animal wastes. The main sources are dogs, horses, septic tanks and farm animals.

Macro Micro and Molecular

Heavy Metals Lead, zinc and copper are the major heavy metals entering the stormwater system via roads, and in the case of lead, via exhaust. Elevated levels can cause death and mutation in animal populations.

Molecular


Roads Interrupt Natural DrainageRoads 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

Keith Stichler, CDR

Various sources!


Roads are the Drainage NetworkRoads are the Drainage Network

And represent a huge wasted catchment


Impervious Watersheds Kill Rivers and Speed up the Water Cycle

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.


Purifying WaterPurifying 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.


Pervious Pavements Act Like a Giant Biofilter

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.


Speed, Volume Sediment Load and PollutionSpeed, Volume Sediment Load and Pollution

Low speed, low volume low distance covered = low pollution and salts

Higher speed, higher volume, more energy, greater distance covered = more pollution and salts

Rainwater does good all the way to the sea. Polluted and salty water do no good at all


Traps Do Not Stop Micro and Molecular PollutionTraps Do Not Stop Micro and Molecular Pollution

www.azstorm.org/public_edu.php

Source www.dpiw.tas.gov.au/.../RPIO-4YJ3KA?open

Traps are useless for stopping most pollutants other than those that are unsightly


The Functions of RoadsThe 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


Current Road Designs are Not SustainableCurrent Road Designs are Not SustainableTraffic Engineers

Drainage and Traffic Engineers

Sewerage Engineers

Electrical Engineers

Telecommunication Engineers

Gas Engineers

Hydraulic Engineers

Management

Ratepayers

The various groups with an interest in roads do not work together holistically

Geo Technical Engineers

How often do you see the same section of road dug up repeatedly in quick succession?

Environmental Scientists


Changing the Road ParadigmChanging 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


Building a New ModelBuilding 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 for these purposes.


Heads First for ActionHeads 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


Our Guide - Biomimicry - GeomimicryOur 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


Pervious Concrete Pavement - Addressing the IssuesPervious Concrete Pavement - Addressing the Issues

Image source: http://www.perviouspavement.org/

Pervious pavement is a unique and effective means of addressing environmental issues


TecEco Permecocrete - Thinking About Water and Roads

TecEco Permecocrete - Thinking About Water and Roads

Optional impervious layer, underground drainage and storage. Dual water supply or parks etc. only.

Optional groundwater recharge

The substrate must be properly designed

Moisture retention

Cleansing microbial activity and oxygenation

Cooling Evaporation

Pavements are not just for vehicles. They must do much more

CO2 CO2CO2 CO2 CO2

CO2

Sequestration


Holistic Roads for the FutureHolistic Roads for the Future

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.

Conventional bitumen or concrete footpath pavement

Impermeable layer (concrete or plastic liner) angling for main flow towards collection drains

Pervious Eco-Cement concrete pavement (Permecocrete) surface using recycled aggregates

Pervious gravel under for collection, cleansing and storage of water

Collection drains to transport drain or pipe in service conduit at intervals

Services to either side of the road. All in same trench of conduit

Possible leakage to street trees and underground aquifers

Its time for a road re think!

Service conduit down middle of road

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.


Placing Pervious PavementPlacing Pervious Pavement

Source: www.percocrete.com


Finishing Pervious PavementFinishing Pervious Pavement



Laying Pervious PavementLaying Pervious Pavement



Cross Section Pervious PavementCross Section Pervious Pavement



TecEco PermecocreteTecEco 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 accoustic properties– Reduces building maintenance– Cooler Suberbs– Reduced drainage infrastructure costs

• Reduces the need for culverts, pies drains, retention ponds, swales, and other stormwater management devices.

– Less watering of street trees


Environmental AdvantagesEnvironmental 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.


Non Environmental AdvantagesNon 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


Hot City Syndrome and Pervious PavementHot 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! It’s 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?


Solving the Water ProblemSolving the Water ProblemCollecting Rain Water Using Pervious PavementCollecting 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.


TecEco Eco-Cement Pervious PavementTecEco Eco-Cement Pervious Pavement

Allow many mega litres of good fresh water to become contaminated by the pollutants on our streets and pollute coastal waterways

Capture and cleanse the water for our use?

Or

Permecocrete

TecEco have now perfected pervious pavements that can be made out of mono-graded recycled aggregates and other wastes and that sequester CO2.

Permecocrete


TecEco Eco-Cement Permecocrete - Mimicking Nature

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 storage e.g. under drive

Permecocrete pervious pavement

Water featurekeeps water

clean

Pump

All rainwater redirected to pavement filter.


SalinitySalinity 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.html#how) and CSIRO web sites there are two main causes of salinity– irrigation salinity – dryland salinity

• Caused by clearing• Caused by evaporation


Irrigation SalinityIrrigation Salinity According to the Australian National Action plan website at

http://www.napswq.gov.au/publications/salinity.html#how salinity occurs when irrigation 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-salinity-aridity has destroyed many civilisations – will ours be next?

Figure from the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#how


Dryland Salinity – Caused by ClearingDryland Salinity – Caused by Clearing

According to the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#how 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.

TecEco consider this view substantially incorrect. See our web site at http://www.tececo.com/sustainability.salinity_pollution.php and what follows

Figures from the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#how


Dryland Salinity – Caused by EvaporationDryland 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.html


Salinity, Agricultural Practices and Pervious PavementSalinity, Agricultural Practices and Pervious Pavement

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.

Deep rooted salt tolerent species (The PundaZoie company)

Native tree belts

Salinity in untreated areas

Deep drains

TecEco permecocrete roads

Salinity in untreated areas

Salty water

Fresh water

Contoured swales


How Our Theories Differ on SalinityHow 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.

For more information please see our web site at http://www.tececo.com/sustainability.salinity_pollution.php


The Clogging Myth - Cleaning Pervious PavementThe Clogging Myth - Cleaning Pervious Pavement

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.

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 waterwaysFrimokar Australia

high pressure jet and suction cleaning in action


We Must Learn to Recycle Everything Including CO2We 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.

In eco-cement blocks and mortars the binder is carbonate and the aggregates are preferably wastes “Biomimicry - Geomimicry”

We all use carbon and wastes to make our homes!

CO2

C

CO2

Waste

CO2

CO2

Pervious pavement


GeomimicryGeomimicry 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.


Geomimicry for Planetary Engineers?Geomimicry for Planetary Engineers? Large tonnages of carbon were put away during

earth’s 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


Geomimicry for Planetary Engineers?Geomimicry for Planetary Engineers? The answer to the problems of greenhouse gas

and waste is to use them both in building materials.– 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


Economically Driven SustainabilityEconomically 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.


Changing the Technology ParadigmChanging the Technology Paradigm

“By enabling us to make productive use of particular raw materials, technology determines what constitutes a physical resource1”

1.Pilzer, Paul Zane, Unlimited Wealth, The Theory and Practice of Economic Alchemy, Crown Publishers Inc. New York.1990

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


Cultural ChangeCultural 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


Sustainability is Where Culture and Technology MeetSustainability is Where Culture and Technology Meet

Increase in demand/price ratio for greater sustainability due to cultural change.

#

$

Demand

Supply

Increase in supply/price ratio for more sustainable products due to technical innovation.

Equilibrium

ShiftECONOMICSGreater Value/for impact (Sustainability) and economic growth

A measure of the degree of sustainability of an industrial ecology is where the demand for more sustainable technologies is met by their supply.

We must rapidly move both the supply and demand curves for sustainability


Making Pervious PavementMaking 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 pervious 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.

Eco-Cement Permecocrete Pervious PavementSet by absorbing CO2Can use recycled materials as long as they are hard and mono-graded

AsphaltCarcenogenic to workers using it.Becoming more expensive as petroleum supplies dwindle.


Making Carbonate Building Materials to Solve the Global Warming Problem

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


The Gaia Engineering ProcessThe Gaia Engineering Process

Greensols Process

Fossil fuels

Solar or solar derived energy

Oil

MgO

CO2

Coal

CO2

MgCO3

CO2

CO2

Inputs:

Atmospheric or smokestack CO2, brines,waste acid, other wastes

Outputs:

Potable water, gypsum, sodium bicarbonate, salts, building materials, bottled concentrated CO2 (for algal fuel production and other uses).

Carbon or carbon compoundsMagnesium compounds

1.29 gm/l Mg

TecEco MgCO2

Cycle

TecEcoKiln

Carbonate building components

Eco-Cement


TecEco CementsTecEco CementsSUSTAINABILITY

DURABILITY STRENGTHTECECO 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 fo strength, workability, dimensional stability and durability. In Eco-cements carbonation of brucite => nesquehonite, lansfordite and an amorphous phase for sustainability.

PORTLAND

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.


TecEco FormulationsTecEco 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 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 it’s 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 pervious 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 pervious 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.


Tec & Eco-Cement TheoryTec & 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


Tec & Eco-Cement TheoryTec & 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


Why Add Reactive Magnesia?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


Why do Eco-Cements use Magnesium Compounds?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

%5284

44

3

2

MgCO

CO

%43101

44

3

2

CaCO

CO


Strength with Blend & PorosityStrength with Blend & Porosity

0

50

100

150

100-150

50-100

0-50

High OPC High Magnesia

High Porosity

STRENGTH ON ARBITARY SCALE 1-100

Tec-cement concretes

Eco-cement concretes

Enviro-cement concretes


Solving Waste & Logistics ProblemsSolving 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


Eco-CementsEco-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.


Eco-CementsEco-Cements 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 + H2O <=> Mg(OH)2

Mg(OH)2 + CO2 + H2O <=> MgCO3.3H2O

58.31 + 44.01 <=> 138.32 molar mass (at least!)24.29 + gas <=> 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”.


Carbonation is Proportional to PorosityCarbonation is Proportional to Porosity

CarbonationRate

Macro Porosity


Carbonation is Proportional to TimeCarbonation is Proportional to Time

% Carbonation

Time

100 %

180 days


CO2 Abatement in Eco-CementsCO2 Abatement in Eco-Cements

Eco-cements in pervious products absorb carbon dioxide from the atmosphere. Brucite carbonates forming lansfordite, nesquehonite and an amorphous phase, completing the thermodynamic cycle.

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.

.299 > .241 >.140 >.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.

Capture CO211.25% mass% reactive magnesia, 3.75 mass% Portland cement, 85 mass% aggregate.


Capture CO2. Fly and Bottom Ash11.25% mass% reactive magnesia, 3.75 mass% Portland cement, 85 mass% aggregate.


For 85 wt% Aggregates

15 wt% Cement

Greater Sustainability


Eco-Cement Strength DevelopmentEco-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%.

Mg(OH)2 + CO2 MgCO3.5H2O

From air and water


Eco-Cement Strength Gain CurveEco-Cement Strength Gain Curve

Eco – Cement Concrete with 50% reactive magnesia

OPC Concrete

HYPOTHETICAL STRENGTH GAIN CURVE OVER TIME (Pozzolans added)

MPa

Log Days Plastic Stage

?

?

?

?

7 14 28 3

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.


Chemistry of Eco-CementsChemistry 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.


Eco-Cement ReactionsEco-Cement Reactions

Hardness: 2.5 - 3.0 2.5

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

Solubility (mol.L-1): .00015 .01 .013 (but less in acids)

Magnesia Brucite Amorphous Lansfordite

MgO + nH2O Mg(OH)2.nH2O + CO2 MgCO3.nH2O + MgCO3.5H2O + MgCO3.3H2O

In Eco - Cements

Hardness: 2.5 3.5

Form: Massive Massive or crystalline More acicular

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

Portlandite Calcite

Ca(OH)2 + CO2 CaCO3

Compare to the Carbonation of Portlandite

Aragonite

Nesquehonite


Eco-Cement Micro-Structural StrengthEco-Cement Micro-Structural Strength

Elongated growths of lansfordite and nesquehonite near the surface, growing inwards over time and providing microstructural strength.

Portland clinker minerals (black). Hydration providing Imperfect structural framework.

Micro spaces filled with hydrating magnesia (→brucite) – acting as a “waterproof glue”

Flyash grains (red) reacting with lime producing more CSH and if alkaline enough conditions bonding through surface hydrolysis. Also acting as micro aggregates.

Mysterious amorphous phase?


CarbonationCarbonation

Eco-cement is based on blending reactive magnesium oxide with other hydraulic cements and then allowing the Brucite and Portlandite components to carbonate in pervious 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


Aggregate Requirements for CarbonationAggregate 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 pervious– requiring a coarse fraction to cause physical air voids and some vapour

permeability. Coarse fractions are required in the aggregates used!


CO2 Abatement in Eco-CementsCO2 Abatement in Eco-Cements

Eco-cements in pervious products absorb carbon dioxide from the atmosphere. Brucite carbonates forming lansfordite, nesquehonite and an amorphous phase, completing the thermodynamic cycle.

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


Portland Cements15 mass% Portland cement, 85 mass% aggregate


.299 > .241 >.140 >.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.

Capture CO211.25% mass% reactive magnesia, 3.75 mass% Portland cement, 85 mass% aggregate.


Capture CO2. Fly and Bottom Ash11.25% mass% reactive magnesia, 3.75 mass% Portland cement, 85 mass% aggregate.


For 85 wt% Aggregates

15 wt% Cement

Greater Sustainability


TecEco Cement LCATecEco 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


Net Emissions/Sequestration ComparedNet Emissions/Sequestration Compared

Net Emissions (Sequestration) per kg Cement

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

Por

tland

Cem

ent

Mag

nesi

a

Lim

e

Tec

-Cem

ent

Eco

-Cem

ent

Lim

e M

orta

r

Env

iro-C

emen

t

Net Emissions(Sequestration) per kgCement

(Gaia Engineering Assumed)


Rosendale Concretes – Proof of DurabilityRosendale 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.net/rosendale_natural_cement_.html


A Post – Carbon AgeA Post – Carbon Age

Prehistoric Classic Renaissance Industrial Revolution Contemporary Post Carbon Age

Recyclable Recyclable

CO2

Wattle & daub Stone Mud brick Etc.

Stone

Stone Brick

Concrete Concrete Steel Aluminium

Eco-cements

We all use carbon and wastes!


Eco-Cement compared to Carbonating Lime Mortar. 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 pervious carbonated concrete.


A More Sustainable Built EnvironmentA More Sustainable Built Environment

MAGNESIUM CARBONATE

ECO-CEMENTCONCRETES

SUSTAINABLE CITIES

CO2

PERMANENT SEQUESTRATION & WASTE UTILISATION (Man made carbonate rock incorporating wastes as a building material)

Pareto’s principle -80% of the build environment in non structural and could be carbonate from Greensols held together by Eco-Cements

CO2

MgOTECECO KILN

RECYCLED BUILDING MATERIALS

OTHERWASTES

“There is a way to make our city streets as green as the Amazon rainforest”. Fred Pearce, New Scientist Magazine

CO2 + H2O =>Hydrocarbons compounds using bacteria

GREENSOLS

CO2


ConclusionConclusion 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

pervious pavement

Documents