Concrete is the most used construction material. Find out here the concrete sustainable features, the cement Carbon Footprint. Also get an answer if concrete is actually sustainable? How can concrete go greener? Presented at the Middle East Concrete event in Dubai 2014 by Mamdouh Hamouda, Arkan Architects & Engineers. For more: www.middleeastconcrete.com

1. CONCRETE
SUSTAINABILITY

2. What is
Sustainability?
Sustainability means
meeting the present needs
without compromising the
needs of future generations

3. The three pillars of Sustainable Development
Concrete buildings
must provide a safe,
healthy & comfortable
interior, eg :
Structural integrity
Weather & fire
protection
Acoustic
performance
SOCIAL
Concrete buildings
must be durable, low
maintenance, reusable
and energy efficient
ECONOMIC
Energy consumption &
GHG emission over the
whole lifecycle should
be low
ENVIRONMENT

4. Concrete is the most used
construction material
According to
World Business
Council for
Sustainable
Development
2009
Over 25 billion
tons are placed
each year

5. Concrete Sustainable Features
It is fire resistant
Its acoustic performance is high
It is durable and is characterized by high longevity
Its thermal mass is high
Its adaptability

6. Concrete Sustainable Features (continued)
Its recyclability
Concrete paving reduces tire friction hence fuel
consumption
Well insulated concrete envelop reduces energy
consumption
Concrete is an economical building material

7. What is not green in concrete?
Cement high embodied energy*
Cement production reduces the resources of
good limestone & clay

8. Embodied energy’ is “the sum of the
energy requirements associated,
directly or indirectly, with the
delivery of a good or service”
(Cleveland & Morris, 2009)
Definition (1)

9. What is not green in concrete? (continued)
A large amount of water is consumed in
production process
Energy consumed in crushing aggregate
Energy consumed in transportation

10. Cement Impact:
96% of the carbon
Footprint* of concrete
85% of the
embodied energy
Courtesy:
Schokker, (2010), The Sustainable Concrete Guide – Applications, U.S. Green Concrete Council

11. Carbon Footprint is “the total set of
greenhouse gas emissions caused
directly or indirectly by an individual,
organization, event or product”
(Carbon Trust 2007)
Definition (2)

12. A FOCUS ON THE CEMENT PRODUCTION PROCESS
CO2 EMISSION
Calcination (Releasing CO2 from limestone):
The CO2 generated by calcination (65% of overall CO2 emission)
is fixed by the chemical nature of limestone
Burning fuel to heat the kiln (35% of CO2 emission)
Recent manufacturing improvements have significantly reduced the amount of CO2
generated from heating process
(Portland Cement Association 2008)

13. Bearing such limitations in mind, is concrete sustainable?
Sustainability assessment should be
considered comprehensively over the entire
lifecycle of concrete, and not on production
process only

14. Life Cycle Assessment (LCA)
LCA is a method to evaluate a product (or
system) in terms of impact on the
environment over the full course of its life

15. Wise use of concrete is crucial for
“Sustainable Development” due to:
The huge volume of concrete used
AND
Associated resources & energy
consumed to make it

16. How can concrete go greener - 1
REUSE:
REUSE PREVIOUSLY CONSTRUCTED CONCRETE ELEMENTS
Specify and use Durable Concrete.
This has a paramount significance because DURABILITY
means multiple re-use, longer lifespan and less resources
and energy spent

17. How can concrete go greener - 2
REDUCE
1. REDUCE THE CONTENT OF PORTLAND CEMENT
Part replacement of cement by supplements (Pozzolan), most common of which are:
Fly ash: A by‐product of the combustion of pulverized coal in
power plants. (15 ‐ 30% )
Ground Granulated Blastfurnace Slag - GGBS (30% - 60% )
Microsilicawhich is a byproduct from the production of silicon or ferrosilicon
alloy. (5 -15%)

18. How can concrete go greener - 3
REDUCE
2. USE WATER SPARINGLY
Use treated rainwater and recycled gray water
Reduce the water/ cementitious ratio
Use curing compound where possible/practical
In concrete walls, leave the formwork in place 2 – 3 days longer
Treat and reuse the wash water collected at the sites of batching plants.
Use light weight aggregate for internal curing* (where strength requirements permits)

19. DEFINITION
Internal curing is the
continued curing of
concrete from water
released internally
from porous aggregate
Courtesy:
Schokker, (2010), The Sustainable Concrete Guide, US Green Concrete Council
USE WATER SPARINGLY, cont.

20. How can concrete go greener - 4
RECYCLE
Use recycled concrete debris as course aggregate
Recycle rebar leftovers

21. How can concrete go greener - 5
USE THE RIGHT ADMIXURE(S)

22. How can concrete go greener - 6
USE THE RIGHT AGGREGATE
Give preference to aggregate mined from local or non‐remote queries
Give preference to natural gravel and sand as opposed to crushed aggregate
Avoid coarse aggregate finer than 20 mm
Use light weight aggregate for better insulation & internal curing

23. How can concrete go greener - 7
USE THE RIGHT REINFORCEMENT

24. How can concrete go greener - 8
INTEGRATE CONCRETE IN GREEN BUILDING ELEMENTS

25. How can concrete go greener - 9
USE “AERATED AUTOCLAVED CONCRETE” IN THE BUILDING ENVELOPE

26. How can concrete go greener - 10

27. ENHANCEMENT ACTION SUSTAINABILITY RELATED GAINS
Reducing W/C ratio Enhances
durability
Help conserving water
resources
Cement part replacement by
Pozzolan
Enhances
durability
Substantially reduces
amount of cement
Using light weight, porous
aggregate
Reduces heat
conductivity
Enables internal curing
SUSTAINABILITY ENHANCING ACTIONS WITH DUAL GAINS

28. THANK YOU FOR
ATTENDING
A wealth of presentations and reports are available at
www.middleeastconcrete/presentations
PLEASE DON’T FORGET TO COLLECT YOUR ATTENDANCE CERTIFICATE