sustainability of cement and concrete industries · use opm, such as natural pozzolans, coal fly...

Center for By-Products Utilization

Sustainability of

Cement and Concrete Industries

By

Tarun R. Naik, Ph. D., P. E.

Emeritus Professor, UW-Milwaukee

Presented at Dipartimento di Scienze e Ingegneria della Materia, dell'Ambiente ed

Urbanistica (SIMAU), Facoltà di Ingegneria

Università Politecnica delle Marche (UNIVPM)

Ancona, Marche, ITALY. 1 luglio 2015


UWM Center for

By-Products Utilization

For sustainable developments: Reduce,

Reuse, Recycle, Repair, and Restore.

Minimize use of manufactured materials.Maximize environmental benefits: resource conservation,

clean water, and clean air should be the concern of everyone.


Basic Approach

WA$T€ is wasted if you waste it,

otherwise it is a resource. Resource is

wasted if you ignore it and do not

conserve it with holistic best practices

and reduce societal costs. Resource is

for the transformation of people

and the society.

Focus on turning brown fields into green fields – opportunities are here, now!!


Basic Approach

Recycle. Recycle as is.

Whenever possible, recycle without

additional processing

(i. e., without adding any cost to it).

Disposal leads to GHGs.


Solid Waste ManagementLandfills contributes to global climate change

because it releases GHGs (Water Vapor,

Methane, and CO2). “Methane (is) 20 more

powerful than CO2.” Therefore, recycling

“creates a double carbon saving.” (Financial

Times, March 1, 2009).

US-EPA declared in April 2009 that CO2 is a

danger to human health (Financial Times April

18/19, 2009).

Alternatives? Increase recycling rates, as well

as MSW to energy and composting.


Progression to 21st Century

Solid Waste Management

Recycling, sustainable management of

resources (SMR), sustainable

infrastructures, durable construction

materials, improved air quality, global

climate change, reduced GHGs, CO2

reduction & sequestration

and carbon offsets.


Exceeding Expectations

• Imagine . . .

I would like for everyone to close

their eyes for 5 seconds and imagine

our world without concrete.


World Without Concrete


Why Sustainable Concrete?

• Concrete is the backbone of all construction and development activities.

• It has portland cement as the key ingredient.

• Production of portland cement is not eco-friendly:

It consumes enormous quantities of natural resources


Why Sustainable Concrete? (cont’d)

Cement production releases a significant amount of GHGs resulting in adverse environmental impact;

It is responsible for up to about 7% of total anthropogenic GHG emissions; and,

Each construction activity involving portland cement requires new cement as it does not have significant potential for recycling.


Sustainable Concrete

• It should have little impact on the

environment.

• It should use industrial by-products

and other recyclable materials as

substitute for natural or

manufactured ingredients of the

concrete.


Sustainable Concrete (cont’d)

• It should have a low inherent energy

requirement.

• It should be produced with little

waste.

• It should be highly durable.


Durability, and, therefore,

sustainability of properly designed and

constructed concrete structures

depends primarily upon the quality of

the materials of construction and other

simple, but critical, steps.


Concrete construction can last 100

years or more if five simple steps are

followed:

(1) materials selection;

(2) structure design;

(3) construction;

(4) quality management; and,

(5) timely evaluation,

maintenance, repair, and

restoration.


Introduction

Sustainability is important to the well-

being of our planet, continued growth of

a society, and human development.

Concrete is one of the most widely used

construction materials in the world.


Concrete is by far the most important

building material. Worldwide, more than

10 billion cubic yards are produced each

year (2010).

The reasons for the popularity of

concrete are well known. If properly

proportrioned and produced, concrete

has excellent mechanical and durability

properties.


Sustainable Cement

and Concrete

Entire geographical areas are running low of limestone resource to produce cement.

Travel distance to bring limestone to produce cement, therefore, has increased.

This leads to increased GHGs.

Major island-nations and metropolitan areas are running out of sources of aggregates for making

concrete and other cement-based materials.


• A sustainable concrete structure is one that is

constructed so that the total societal impact

during its entire life cycle, including during its

use, is minimum.

• Designing for sustainability means accounting

in the design of short- and long-term

consequences on the societal impact.

Therefore, DURABILITY is the key issue.

• Blended cements (OPC + OCM), liquid

admixtures, and powder additives are needed

to continue to improve durability.


• Over six billion tons of non-hazardous

by-product materials are produced each year in USA (2008). (8+/- billion tons of

industrial solid waste based on 1980s figures.) At an average cost of $30 per ton, it would cost B$180 to throw it all away.

• These by-products are from agricultural sources, domestic/post-consumer sources, industrial sources, and materials processing sources.


Infrastructures are Dependent on Durable Concrete


Energy, Environment, and

Economy Related Issues in the

Production of Portland Cement


Energy Related Issues

After aluminium and steel, themanufacturing of portland cementis the most energy-intensive process.

The manufacturing of one tonne ofportland cement requires about sixmillion BTU of energy (equivalentto about 500 Kg. of coal per tonne ofcement produced).


Environmental Issues

The production of one tonne of

portland cement releases

approximately one tonne of CO2

and other greenhouse gases

(GHGs) into the atmosphere.


Economic Issue

The cost of a new portland

cement plant is in the order of

300+ million Euros per one

million tonne of installed

capacity.


Portland Cement (OPC)

is not environmentally very

friendly material.

As good engineers, we must

reduce its use in concrete.


Extinct Homo Sapiens

2500 BC - 2100 AD ?

Cause of death :

Friendly fire; by excessive GHG

emissions and excessive use of

natural resources, including

cement and water.


SOLUTIONAs good engineers, we must use more environmentally friendly other cementitious/pozzolanic materials (OCM/OPM) in concrete. ..use blended cements.

Use OPM, such as natural pozzolans, coal fly ash, g. g. b. f. slag, silica fume, rice-husk ash, wood/bio-mass ash, agricultural products ash, limestone/quarry fines (OCM), etc.

Use more application specific high-quality & durable aggregates, and organic admixtures.

Use less water.


Concrete

is environmentally very

friendly material.

As good engineers, we

must use more of it in

construction.


As good engineers, we

must reduce the use of

water; and, we must use

more organic, liquid,

admixtures or inorganic

powder additives, or both.


Blended “ROMAN” Cement

• Blended cement is one of the most

common efforts to make the concrete

more sustainable and less expensive.

• It involves reducing and replacing a

portion of the portland cement clinker

with suitable industrial by-products or

other recyclable (“secondary”) materials.


Roma Coliseum, AD 72 - 81

Arena di Verona: AD 30

Cement and Concrete Roots


Old Concrete: cement, water, sand, and

stone.

New Concrete: PLUS Liquid

admixtures…PLUS Mineral

admixtures/additives.

Modern-day Green Concrete: PLUS

recyclable materials as a replacement

of cement, water, sand, or stone; or,

all of these materials


Blended Cement (cont’d)

• Can be used for all concrete construction

activities.

• Reduce the use of natural or

manufactured materials, and reduce

emission of greenhouse gases, by using

recycled materials.

• The worldwide potential for GHG

reduction through blended cement is

between 5 – 20 %.


Blended Cement (cont’d)

• More environmental friendly than

portland cement because it provides

energy and ecological savings, as well

as technical benefits such as increased

strength, improved impermeability,

increase resistance to chemical attacks,

and reduced heat of hydration.


Volcanic Ash


Bio-Mass/Wood Ash,

including rice husk ash

(RHA), and other

agricultural products ash


Other Useful Materials

• Powdered glass along with other pozzolanic

materials (e.g., volcanic ash, coal ash, bio-

mass/wood ash, etc.) can be used as a partial

replacement of cement.

• Pulp and paper mill residual solids can be

used as an additive in concrete for

enhancing durability properties.


Scanning electron micrograph of Residuals


Residual Fiber Reinforcing a Micro-crack in

Concrete


Gypsum-based wallboard;

limestone quarry dust;

marble and stone cutting

fines; and,

lime from water

purification plants.


Waste Washed-water

• Waste wash-water from ready–mixedconcrete plants could be used in themanufacture of sustainable concrete withoutadverse effects on concrete properties.

• Studies have suggested waste washed-watercan be used for a partial replacement ofpotable water in concrete manufacture andfor the curing of concrete.


Geopolymer Concrete (GPC)

• GPC is a “new” technology for

manufacturing of sustainable concrete.

• It is portland cement free concrete.

• This concrete does not require cement,

or water for curing, and utilizes by-

product materials (GGBFS and/or fly

ash, with alkalis). Therefore, it is more

eco-friendly and sustainable.


• Eliminate waste and take life-cycle

responsibility.

• Think Energy, Ecology, Economy,

and Equity.

• Acknowledge and balance these

four-Es.


“The issue is not environment vs.

development or ecology vs. economy; the

two can be (and must be) integrated.”

“We have the human and material

resources needed to achieve sustainable

developments, not as an abstract concept

but as concrete reality”.

Kofi Annan, U. N. Secretary-General, Johannesburg, South Africa, August 2002.


Conclusions

Recycling not only helps in reducing disposal costs, but also helps to conserve natural resources, providing technical and economic benefits, as well as helps in reducing GHGs.

This is sustainability.


Conclusions (Cont’d)

• A sustainable concrete should have a very

low inherent energy requirement, should be

produced with little waste and with recycled

materials, be highly durable, and have

small impact on the environment.


Conclusions (cont’d)

• The cement industry is held responsible for

global climate change to some extent. It

contributes about 7 % of total global GHGs

emissions from fuel use and calcinations

process.

• Use of the blended cement in place of

ordinary portland cement in concrete is one

of the most common efforts to make the

concrete more sustainable.


Sustainable/Durable Concrete

• Use less cement

• Use less water

• Use project specific durable aggregates

• Use powder additives and liquid

admixture


RESOURCE

CONSERVATION

“The earth, the sea (water), and the air

are the concern of every nation.”

President John F. Kennedy, autumn 1963,

in a speech to the U.N. General Assembly.


La bella terra


The Beautiful Earth – La Bella Terra


http://cbu-uwm.info/

<http://www4.uwm.edu/ceas/faculty_profiles/TNaik.html>


Fourth International

Conference on Sustainable

Construction Materials &

Technologies,

Las Vegas, Nevada, USA

August 7-11, 2016


Ringrazio molto

per il vostro

interesse.

Thank you very much

for your interest.


Foundry By-Products


Recycled-Concrete Used for

Aggregates


Post-consumer Glass,

Plastics, and tires


Recycling of Construction &

Demolition Debris in Concrete

• Recycling of C & D debris conserves:

Raw materials, Energy, Water; and,

Reduces the emission of greenhouse gases.

• Most common way of using CD debris is as

aggregates.

sustainability of cement and concrete industries · use opm, such as natural pozzolans, coal fly...

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