Green concrete and its demand on
the cement industry
Mette Glavind
Danish Technological Institute
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Introduction
Definition of sustainable concrete structures
The Danish way
Centre for Green concrete
Evaluation of new supplementary cementing
materials
Future outlook and conclusions
1
Status
An independent
independent,, notnot-for
for-- profit institution.
Approved as a technological service institute by
the Danish Minister of Science, Technology and
Innovation
Objective
The objective of the Danish Technological
Institute is to address the needs of the industrial
sector and society as a whole through the
development and dissemination of technological
innovation
Green Concrete activities at DTI
F DK project: Overview of impact and LCI
F DK project: Guidelines in environmental management
F DK project: Environmental assessment of sewer pipes
F EU project TESCOP: LCA of 10 functional units & cleaner
Technology
F Danish Centre for Green Concrete
F Evaluation of the use of green waste glass
F Nordic network Concrete for the environment
F DK project: List of action and selected activities
F EU network ECO-SERVE
F Nordic project: CO2 uptake
2
Definition of an environmentally
sustainable concrete structure
F
Designed, built, operated or reused in a ressourceefficient manner
F Utilising the inherently environmentally beneficial
properties
The right concrete for the
F Tailor-made for the use
right application
F Total environmental impact during the entire life cycle
reduced to a minimum
Source:: Concrete for the environment - a Nordic network
Source
Criteria
F
F
F
F
F
Use aggregate that is extracted in an environmentally
sound manner
Use cement manufactured using modern production
technology, recycled raw materials and alternative
energy sources.
Be produced at concrete plants where environmental
impact is minimised.
Have an optimal clinker content according to the
intended strength and durability.
Not introduce environmental problems such as
Source:: Concrete for the environment
Source
leaching of heavy metals etc.
a Nordic network
3
Cement consumption divided with concrete
production for ready-mixed industry.
500
400
300
200
Average
UK
Switzerland
Sweden
Spain
Portugal
Poland
Norway
Netherlands
Italy
Ireland
Germany
France
Finland
Denmark
Belgium
0
Austrai
100
Source : ERMCO
Source:
2001 statistics
Typical DK mix designs
Kg/m3
Cement, CEM I
Indoor concrete
SCC indoor concrete
148
168
Fly ash
51
107
Silica fume
12
30
Aggregate
1926
1801
138
152
Water
4
The ”Green Concrete”
consortium
Industrial partners
UNICON
AB SYDSTEN
AALBORG PORTLAND
COWI
MT HØJGAARD
DANISH ROAD DIRECTORATE
TECHNICAL UNIVERSITY OF
DENMARK
DANISH TECHNOLOGICAL
INSTITUTE
Technological Service Institute
AALBORG UNIVERSITY
Universities
5
Overview of results
. The Centre has made it possible to document the technical
properties of green types of concrete and to describe the
environmental impacts of choosing green solutions.
The Centre has
developed a number of
solutions that can be
put directly to use by
the industry both for
large civil structure as
well as for housing.
Environmental targets
F
F
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30% CO2 reduction
20% residual products as aggregate
Concrete industry to use own waste
New types of residual products used
Waste as fuel in cement production
+
F
Not introduce new environmental problems
6
Green strategies
Materials:
F”Green” cement
FMinimize clinker content
FOwn residual products
FAlternative ashes
Structural design:
FNo asphalt or moisture barrier
FEasy to substitute part of
construction
Repair and maintenance
strategies:
FStainless steel
FIncreased cover
FPermanent formwork
A green demonstration bridge
Green types of concrete
§
Ref.concrete (CEM I 42.5)
§ Green cement (CEM 1 52.5)
§ 35-38% FA
§ Sewage sludge incineration
ash
Stainless reinforcement
No moisture barrier and
asphalt
7
Mix design
A-REF
A0
A1
A1
3
3
3
3
kg/m i VOT kg/m i VOT kg/m i VOT kg/m i VOT
Low-alkali C (CEM I 42,5)
317
Rapid C (CEM I 52,5)
317
210
238
FA
32
32
142
135
SF
18
18
18
18
Water
153
153
125
133
W/c
0,42
0,42
0,41
0,41
FA in % of powder
9
9
38
35
CO2 –reduction
33
51
45
Application
Foundations Foundations Foundations Bridge deck
Columns
Columns
Columns
Bridge deck Bridge deck
3.500
3.000
2.500
2.000
1.500
1.000
500
-
Asphalt
Concrete
Maintenance
Construction
Asphalt
A3
A1
A0
AR
Reinforcement
Br
idg
e3
4
kg CO2 per year
CO2- emission - 74 years
Concrete
8
Model in evaluation of supplementary
cementing materials
The model is presented in
a Danish publication from the
Green Concrete project, see
www.gronbeton.dk
Model
By-product
1. Initial evaluation of suitability
2. Initial testing
3. Supplementary testing
9
Model – phase 1
By-product
Which constituent does the by-product replace ?
1. Initial evaluation
•
SiO2, Al 2O 3, Fe 2O3 – puzzolanic reaction
§
Harmful substances
§
Heavy metals
§
Other substances (e.g. MgO, P 2O 5)
2. Initial testing
3. Suppl. testing
Model – phase 2
By-product
1. Design recipes
2. Determine the traditional properties
1. Initial evaluation
2. Initial testing
3. Suppl. testing
§
Consistence and changes in the consistence
§
Air content and changes in the air content
§
Strength development
§
Heat development
§
Bleeding, hardening time, etc.
§
Frost resistance
3. Correct recipes, repeat testing
10
Model – phase 3
By-product
1. Initial evaluation
Evaluate initial results, make corrections in mix
design, carry out supplementary tests of:
•
Mechanical properties
•
Durability properties
•
Execution properties
•
Fire resistance properties
2. Initial testing
3. Suppl. testing
Conclusion - Model
By-product
Are there any limitations in the possible
applications ?
1. Initial Evaluation
Is it allowed to use this by-product according to
valid standards (e.g. EN 206-1) ?
2. Initial Testing
What is the environmental impact from this new
type of concrete ?
3. Suppl. testing
Can the concrete be produced and handled the
same way as ordinary concrete ?
11
Waste glass
Crushing
Clear glass
350 m 2/kg
Clear glass
500 m 2/kg
Green glass Green glass
500 m 2/kg
350 m 2/kg
Grinding
Aalborg
White
Example with glass fillers
Glass filler
Blaine 500
SiO 2
A l2O 3
F e 2O 3
C r2 O 3
CaO
MgO
N a2O
K 2O
TiO 2
BaO
66,72
1,48
0,41
0,19
10,87
0,84
13,09
0,48
<0,03
0,03
12
Initial testing - results
Voervadsbro-sand (ikke-reaktivt)
0,3
150
Beton-ref
100
Beton-G350
50
0
ekspansion [%]
afskalning [g/m²]
200
0,2
G350
0,1
K350
0,0
0
0
7
14
21
28
35
42
49
56
4
12
16
20
-0,1
tid [døgn]
tid [uger]
Nymølle-sand (reaktivt)
60
50
0,4
40
Beton-ref
30
Beton-G350
20
10
0
0
7
14
21
28
35
tid [døgn]
42
49
56
ekspansion [%]
trykstyrke [MPa]
8
0,3
ref
FA
0,2
G350
0,1
G500
K350
0,0
-0,1
0
4
8
12
16
20
tid [uger]
Overall evaluation of glass fillers
F
Phase 1 and 2 of the model showed that glass fillers for
concrete (grey and white) is a possibility
F Supplementary testing is needed
F EN 206 allows the use of glass fillers for concrete in all
exposure classes if it is valid in the place of use, or if a
national standard is prepared
F Environmental impacts have only been discussed – no
tests have been carried out
13
Future outlook and conclusions,
1
Reduce environmental impact from concrete
constructions and use concrete to the benefit
of the environment
Increased use of concrete
Future outlook and conclusions,
2
Selected trends:
F
Optimise clinker content - CEM II cements and/or
supplementary cementing materials
F SCC will increase need of supplementary cementing
materials
F Focus on thermal capacities due to new EU directive
14
Primary energy (GJ/m3)
Reinforced concrete office building
16
14
12
10
Power
Heating
Building materials
8
6
4
2
0
0
50
Working life (years)
Future outlook and conclusions,
2
Selected trends:
F Optimise clinker content - CEM II cements and/or
supplementary cementing materials
F SCC will increase need of supplementary cementing
materials
F Focus on thermal capacities due to new EU directive
F Use carbonation in CO2 assessments
15
CO2 emission pr. kg cement
1,2
kg CO2/kg cement
1
0,8
0,6
Carbonisation
0,4
Calcining
0,2
Grinding
0
-0,2
-0,4
Fuel
?
-0,6
Total CO2 emissions for bridge
with a lifetime of 74 years
250
200
Maintenance
150
Construction
Reinforcement
Concrete
100
50
0
Excl. Carbonation
Incl. Carbonation
16
The right
concrete for the
right
application
17