Performance based specifications for concrete –an approach to design climate friendly concrete structures?
Christoph Müller
Green Transition of Cement and Concrete Production
in Denmark
DTI Taastrup, 28 February 2019
Performance characteristics of concrete
2
▪ Site relevant (robust) fresh concrete
properties
▪ Mechanical properties
(Compressive strength etc.)
▪ Durability performance
Validation of durability performance for concrete
Experience Testing (laboratory)
Description/
deemed-to-satisfy (DTS) rules
Assessment background/
limit values
Calculation
Limit state
Performance based on
▪ EN 206 + NAR
▪ Exposure classes
▪ min c, max w/c
▪ cmin etc.
▪ Test procedures
▪ CEN/TR 16563
▪ European technical
assessment (EAD/ETA)
▪ Models
▪ fib Model Code „Service Life
Design“
▪ ISO 16204
3
Validation of durability performance for concrete
Experience Testing (laboratory)
Description/
deemed-to-satisfy (DTS) rules
Assessment background/
limit values
Calculation
Limit state
Performance based on
▪ EN 206 + NAR
▪ Exposure classes
▪ min c, max w/c
▪ cmin etc.
▪ Test procedures
▪ CEN/TR 16563
▪ European technical
assessment (EAD/ETA)
▪ Models
▪ fib Model Code „Service Life
Design“
▪ ISO 16204
4
Recommended limiting values for concrete in EN 206
Exposure classes
Maximum w/c
Miniumum
strength class
Minimum
cement content kg/m³
XC1 XC2 XC3 XC4XS1
XD1
XS2
XD2
XS3
XD3
Carbonation-induced corrosion
Chloride-induced corrosion
XS = Sea water
XD = Chloride from other
than from sea water
0.65 0.60 0.55 0.500.50
0.55
0.45
0.550.45
C20/25 C25/30 C30/37 C30/37 C30/37C35/45
C30/37C35/45
260 280 280 300 300320
300
340
320
Minimum
air content %- - - - - - -
5
Recommended limiting values for concrete in EN 206
Exposure classes
Maximum w/c
Miniumum
strength class
Minimum
cement content kg/m³
XC1 XC2 XC3 XC4XS1
XD1
XS2
XD2
XS3
XD3
Carbonation-induced corrosion
Chloride-induced corrosion
XS = Sea water
XD = Chloride from other
than from sea water
0.65 0.60 0.55 0.500.50
0.55
0.45
0.550.45
C20/25 C25/30 C30/37 C30/37 C30/37C35/45
C30/37C35/45
260 280 280 300 300320
300
340
320
Minimum
air content %- - - - - - -
6
National Application Rules
Cement application in the EU: Examples for XF1
Statemax.
w/ceq
min.
c CEM
I
CEM IICEM III CEM IV CEM V
S L/LL M
kg/m³ A B A B A B A B A B A B
Austria 0.55 300 x x x x (x) x (x) x (x)
Belgium 0.55 300 x x x x x x x x x (x)
Denmark 0.55 150 (x) (x)
France 0.60 280 x x x x x x x x x x x x x
Germany 0.60 280 x x x x ● (x) (x) x x ● (x) (x) (x)
Italy 0.50 320 x x x x x x x x x x x x x
Netherlands 0.55 300 x x x (x) (x) (x) (x) x x (x) (x) (x) (x)
United Kingdom 0.60 280 x x x x x x x (x) (x)
x (x) ●not mentioned use allowed with limitations * use not allowed
* an (x) Indicates that there are qualifications, e.g. types of main constituents
7
Cement application in the EU: Examples for XF1
Statemax.
w/ceq
min.
c CEM
I
CEM IICEM III CEM IV CEM V
S L/LL M
kg/m³ A B A B A B A B A B A B
Austria 0.55 300 x x x x (x) x (x) x (x)
Belgium 0.55 300 x x x x x x x x x (x)
Denmark 0.55 150 (x) (x)
France 0.60 280 x x x x x x x x x x x x x
Germany 0.60 280 x x x x ● (x) (x) x x ● (x) (x) (x)
Italy 0.50 320 x x x x x x x x x x x x x
Netherlands 0.55 300 x x x (x) (x) (x) (x) x x (x) (x) (x) (x)
United Kingdom 0.60 280 x x x x x x x (x) (x)
x (x) ●not mentioned use allowed with limitations * use not allowed
* an (x) Indicates that there are qualifications, e.g. types of main constituents
8
Cement application in the EU: Examples for XF1
Statemax.
w/ceq
min.
c CEM
I
CEM IICEM III CEM IV CEM V
S L/LL M
kg/m³ A B A B A B A B A B A B
Austria 0.55 300 x x x x (x) x (x) x (x)
Belgium 0.55 300 x x x x x x x x x (x)
Denmark 0.55 150 * (x) (x)
France 0.60 280 x x x x x x x x x x x x x
Germany 0.60 280 x x x x ● (x) (x) x x ● (x) (x) (x)
Italy 0.50 320 x x x x x x x x x x x x x
Netherlands 0.55 300 x x x (x) (x) (x) (x) x x (x) (x) (x) (x)
United Kingdom 0.60 280 x x x x x x x (x) (x)
x (x) ●not mentioned use allowed with limitations use not allowed
9
* under severe and very severe conditions (e. g. XF3/XF4) minimum fines content ≥ 375 kg/m3
Well-tried and proven in practice
10
Well-tried and proven in practice
Experience
▪ locally available materials
▪ ambient conditions
▪ local design/building tradition
11
Well-tried and proven in practice
Experience
▪ locally available materials
▪ ambient conditions
▪ local design/building tradition
Performance criteria
▪ Fresh concrete properties
▪ Compressive strength
12
Well-tried and proven in practice
Experience
▪ locally available materials
▪ ambient conditions
▪ local design/building tradition
Performance criteria
▪ Fresh concrete properties
▪ Compressive strength
Status-quo (CEN/TC104/SC1 N1040)
▪ No CEN Member Country operates a system where the specification of
carbonation resistance, chloride resistance and freeze-thaw resistance
is only based on tests.
▪ Switzerland has both performance requirements and limiting values.
13
Validation of durability performance for concrete
Experience Testing (laboratory)
Description/
deemed-to-satisfy (DTS) rules
Assessment background/
limit values
Calculation
Limit state
Performance based on
▪ EN 206 + NAR
▪ Exposure classes
▪ min c, max w/c
▪ cmin etc.
▪ Test procedures
▪ CEN/TR 16563
▪ European technical
assessment (EAD/ETA)
▪ Models
▪ fib Model Code „Service Life
Design“
▪ ISO 16204
14
Validation of durability performance for concrete
Experience Testing (laboratory)
Description/
deemed-to-satisfy (DTS) rules
Assessment background/
limit values
Calculation
Limit state
Performance based on
▪ EN 206 + NAR
▪ Exposure classes
▪ min c, max w/c
▪ cmin etc.
- New materials without
long term experience
- Special conditions (e.g.
ASR)
▪ Models
▪ fib Model Code „Service Life
Design“
▪ ISO 16204
15
Which properties must be proven?
Application Properties to be checked
Interior components in exposure class XC1 (dry)▪ Suitable (robust) fresh concrete properties
▪ Mechanical properties (Compressive strength etc.)
Exposure class Risk of corrosion/cracking due to carbonation during
the service life
XC1
(indoor air)
Concrete will carbonate rapidly, but the rate of corrosion is
too slow to cause cracking
16
Which properties must be proven?
Application Properties to be checked
Interior components in exposure class XC1 (dry)▪ Suitable (robust) fresh concrete properties
▪ Mechanical properties (Compressive strength etc.)
Components in exposure class XC3 or exterior
components in exposure class XC4/XF1
▪ Suitable (robust) fresh concrete properties
▪ Mechanical properties (Compressive strength etc.)
▪ if proven: „Strength is a proxy for durability“
Exposure class Risk of corrosion/cracking due to carbonation during
the service life
XC1
(indoor air)
Concrete will carbonate rapidly, but the rate of corrosion is
too slow to cause cracking
XC3 More rapid carbonation than in XC4 but a slower rate of
corrosion
XC4 Slower rate of carbonation than in XC3 but a more rapid
rate of corrosion
17
Passive / moderate conditions
Compressive strength „as a proxy“ for carbonation
Source:
Tilo Proske, Moien Rezvani, Sebastian Palm,
Christoph Müller, Carl-Alexander Graubner:
Concretes made of efficient multi-composite
cements with slag and limestone
Cement and Concrete Composites 89 (2018) pp
107-119
Carbonation test acc. to EAD 15001-00-0301
No 15, Method 1:
7d pre-storage
140d 20 °C/65 % r. H.
0.04 % CO2 concentration
0/8 mm aggregate
18
0,0
2,5
5,0
7,5
10,0
12,5
15,0
17,5
20,0
0 20 40 60 80 100 120
de
pth
of
ca
rbo
nati
on
in
mm
, 7
d p
re-
sto
rag
e, 1
40
d m
ain
sto
rag
e
compressive strength after pre-storage in MPa
CEM I
CEM II/B-M
CEM II/C-M*
CEM VI & CEM X
CEM III/A
* up to 35 mass-% LL
XC3/XC4
Compressive strength „as a proxy“ for carbonation
Source evaluation background:
• CEN/TR 16563, Annex B (August 2013) and
• EAD 15001-00-0301
Carbonation test acc. to EAD 15001-00-0301
No 15, Method 1:
7d pre-storage
140d 20 °C/65 % r. H.
0.04 % CO2 concentration
0/8 mm aggregate
19
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5
5,0
5,5
18 20 22 24 26 28 30 32 34 36 38 40 42 44 46
Ka
rbo
na
tis
ieru
ng
sti
efe
na
ch
14
0d
, 7
d
Vo
rla
ge
run
g in
mm
Druckfestigkeit nach 7d in N/mm²
1
2
3
1 CEM (50K,30S,20LL), w/z = 0,502 CEM (35K,30S,35LL), w/z = 0,403 CEM (20K,30S,50LL), w/z = 0,35
Carb
on
ation
de
pth
in
mm
aft
er
14
0 d
ma
in s
tora
ge
an
d 7
d p
re-s
tora
ge
Compressive strength after pre-storage in MPa
Carbonation to some extend a function of strength
Compressive strength „as a proxy“ for freeze-thaw (XF1)
0
5
10
15
20
25
20 25 30 35 40 45 50 55 60 65 70
Druckfestigkeit 28 d in N/mm²
Daten VDZ; CEM I - CEM II
100 % K
20 % LL
25 % LL
30 % LL
30 % LL; 5 % S
Ma
sse
ve
rlu
st n
ach
10
0 F
TW
in
M.-
%
XF1XF1
Data:Source of data:
Christoph Müller, Eberhard Lang: Durability of Portland limestone and
Portland composite cements CEM II-M (S-LL)
beton 55 (2005), Heft 3 S.131-138, Heft 4 S.197-202, Heft 5 S.266-269
Source of XF1 assessment:
Siebel, Eberhard: Freeze-thaw resistance of concrete without and with
de-icer- evaluation with the cube test, Beton 42, 1992
Loss o
f m
ass a
fter
100 F
TW
in M
.-%
Compressive strength after 28d in MPa
20
Exposure
class
Description of the environment
XF1 Moderate water saturation, without de-icer
Freeze-thaw test acc. to EAD 15001-00-0301
No 17, Method 1: Cube test acc. to CEN/TS 12390-9;
Freeze-thaw resistance with moderate water saturation to some extend a function of strength
Recommended limiting values for concrete in EN 206
Exposure classes
Maximum w/c
Miniumum
strength class
Minimum
cement content kg/m³
XC1 XC2 XC3 XC4
Carbonation-induced corrosion
0.65 0.60 0.55 0.50
C20/25 C25/30 C30/37 C30/37
260 280 280 300
Minimum
air content %- - - -
21
Freeze/thaw attack with
or without de-icing agents
XF1 XF2 XF3 XF4
0.55 0.55 0.50 0.45
C30/37 C25/30 C30/37 C30/37
300 300 320 340
- 4.0 4.0 4.0
Clinker efficient cements – extension of EN 197 - 1
Under
standardizationThe European cement standard:
K-S-LL cements as example
▪ standard describes cements with well
tried and proven constituents
▪ they provide for robust and durable
concretes
▪ concrete standards are national and set
the framework for application
CEM II/C and CEM II/B-LL cements are at least
fit for use in indoor and normal outdoor concrete
22
Cement content and clinker efficiency in concrete
CO2 intensity of concretes
source: data and evaluation VDZ, strength class distribution BTB
Concrete
strength
class
Marketshare
% Germany
2016
min. in
Exposure
Class
C8/10 1.0 X0
C12/15 6.8 ---
C16/20 1.9 XC1, XC2
C20/25 14.4 XC3
C25/30 39.8XC4, XF1, XF2,
XF3, XA1
C30/37 21.4 XS1, XD1, XF4
C35/45 11.2XS/D 2, 3,
XA 2,3
C45/55 0.6 ---
C50/60 0.3 ---
23
64
% =
32 M
iom
3
Cement content and clinker efficiency in concrete
CO2 intensity of concretes
24source: data and evaluation VDZ
▪ CEM II/B-LL cements and
CEM II/C cements:
– at least indoor and “normal”
outdoor concretes
(approx. 65% of all in-situ
concrete in Germany)
▪ Reduction potential of the CO2
intensity approx. 25%
Einstufung BBQ-Klassen (exemplarisch, Entwurf)Which properties must be proven?
Pictures: Rolf Breitenbücher, https://baustoffingenieurwissenschaft.wordpress.com/
Application Properties to be checked
Components in exposure classes XF2/XF3/XF4
XD2/XD3, XS2/XS3, XA2, XA3
▪ Suitable (robust) fresh concrete properties
▪ Compressive strength
▪ Durability tests (strength ≠ durability)
25
Einstufung BBQ-Klassen (exemplarisch, Entwurf)Strength ≠ durability: Freeze-thaw with de-icer
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0 20 40 60 80
scalin
g i
n k
g/m
²
concrete compressive strength in N/mm²
linear, R² = 0.02
c = 320 kg/m3
w/c = 0.50
AEA
26
Concrete compressive
strength in MPa
Freeze-thaw test with de-icer acc. to EAD 15001-00-0301 No 18, Method 1: CDF test acc. to CEN/TS 12390-9
Einstufung BBQ-Klassen (exemplarisch, Entwurf)Strength ≠ durability: Freeze-thaw with de-icer
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0 20 40 60 80
scalin
g i
n k
g/m
²
concrete compressive strength in N/mm²
linear, R² = 0.02
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0 50 100 150 200
sc
ali
ng
in
kg
/m²
CVCDF
linear, R² = 0.85
c = 320 kg/m3
w/c = 0.50
AEA
CVCDF =
HD2d × Air ×P57µm− 0,01µm
Ptotal
27
Concrete compressive
strength in MPa
Freeze-thaw test with de-icer acc. to EAD 15001-00-0301 No 18, Method 1: CDF test acc. to CEN/TS 12390-9
Einstufung BBQ-Klassen (exemplarisch, Entwurf)Strength ≠ durability: Chloride ingress
0
10
20
30
40
50
60
0 20 40 60 80
ch
lori
de
mig
rati
on
co
eff
icie
nt
in
10
-12
m²/
s
concrete compressive strength in N/mm²
exponential,R² = 0.56
c = 320 kg/m3
w/c = 0.50
28
Concrete compressive
strength in MPa
Resistance to chloride
penetration acc. to EAD
15001-00-0301
No 16, Method 1:
NT BUILD 492
Einstufung BBQ-Klassen (exemplarisch, Entwurf)Strength ≠ durability: Chloride ingress
0
10
20
30
40
50
60
0 5 10 15 20
ch
lori
de m
igra
tio
n c
oeff
icie
nt
in
10
-12
m²/
s
CVCl
potential, R² = 0.71
linear, R² = 0.89
0
10
20
30
40
50
60
0 20 40 60 80
ch
lori
de
mig
rati
on
co
eff
icie
nt
in
10
-12
m²/
s
concrete compressive strength in N/mm²
exponential,R² = 0.56
c = 320 kg/m3
w/c = 0.50
CVCl =HD7d
P57µm− 0,02µm
29
Concrete compressive
strength in MPa
Under severe conditions (e. g. chloride attack) durability is not a function of strength
but depend e. g. on the pore size distribution
Resistance to chloride
penetration acc. to EAD
15001-00-0301
No 16, Method 1:
NT BUILD 492
Einstufung BBQ-Klassen (exemplarisch, Entwurf)ASR-Performance Test
30 ASR-Performance test shows the “real” performance of cements (here: effective alkali content!)
Gravel 2/8
w/c-ratio
AE =
crushed Gravel 8/16
OH- in mmol/l
500-600
300-400
Na2O-eq. = total alkali content of the cement
OH- = effective alkalies in the pore solution
Na2O-eq.
Validation of durability performance for concrete
Experience Testing (laboratory)
Description/
deemed-to-satisfy (DTS) rules
Assessment background /limit
values
Calculation
Limit state
Performance based on
▪ EN 206 + NAR
▪ Exposure classes
▪ min c, max w/c
▪ cmin etc.
▪ Test procedures
▪ CEN/TR 16563
▪ European technical
assessment (EAD/ETA)
▪ Models
▪ fib Model Code „Service Life
Design“
▪ ISO 16204
31
Limit state carbonation acc. to Model Code SLD
𝑔𝑐𝑎𝑟𝑏 𝑋, 𝑡 = 𝑑𝑐 − 𝑥𝑐(𝑡)
𝑥𝑐 𝑡 = 2 ⋅ 𝑘𝑒 ⋅ 𝑘𝑐,𝑀𝐶 ⋅ 𝑘𝑡 ⋅ 𝑅𝐴𝐶𝐶,0−1 + 𝜀𝑡 ⋅ 𝐶𝑆 ⋅ 𝑡 ⋅ 𝑊(𝑡)
with
𝑘𝑒: Parameter to consider exposure conditions (rel. Humidity 𝑅𝐻)
𝑘𝑐,𝑀𝐶: Parameter to consider time of curing 𝑡𝑐𝑘𝑡 , 𝜀𝑡: Test method factors [-]
𝑅𝐴𝐶𝐶,0−1 : inverse effective carbonation resistance of dry concrete in (m²/s)/(kg/m³)
𝐶𝑆: CO2-concentration of the ambient air in kg/m³
𝑡: Time from the beginning of carbonation in s,
𝑊(𝑡): Weather function [-]
Limit state function:
Model for carbonation acc. to MC SLD:
with
𝑑𝑐: concrete cover
𝑥𝑐(𝑡): carbonation depth at the time t
32
Limit state carbonation acc. to Model Code SLD
𝑔𝑐𝑎𝑟𝑏 𝑋, 𝑡 = 𝑑𝑐 − 𝑥𝑐(𝑡)
𝑥𝑐 𝑡 = 2 ⋅ 𝑘𝑒 ⋅ 𝑘𝑐,𝑀𝐶 ⋅ 𝑘𝑡 ⋅ 𝑅𝐴𝐶𝐶,0−1 + 𝜀𝑡 ⋅ 𝐶𝑆 ⋅ 𝑡 ⋅ 𝑊(𝑡)
with
𝑘𝑒: Parameter to consider exposure conditions (rel. Humidity 𝑅𝐻)
𝑘𝑐,𝑀𝐶: Parameter to consider time of curing 𝑡𝑐𝑘𝑡 , 𝜀𝑡: Test method factors [-]
𝑅𝐴𝐶𝐶,0−1 : inverse effective carbonation resistance of dry concrete in (m²/s)/(kg/m³)
𝐶𝑆: CO2-concentration of the ambient air in kg/m³
𝑡: Time from the beginning of carbonation in s,
𝑊(𝑡): Weather function [-]
Limit state function:
Model for carbonation acc. to MC SLD:
with
𝑑𝑐: concrete cover
𝑥𝑐(𝑡): carbonation depth at the time t
33
Limit state carbonation – material parameters
Concrete Cement w/c xc [mm] 1) RACC-1
[(mm²/a)/(kg/m³)]
B0-Z1 CEM I 42,5 R 0.65 7.4 9790
B0-Z2 CEM III/A 42,5 N 0.65 11.5 23643
B1-Z1 CEM I 42,5 R 0.50 4.3 3260
B1-Z2 CEM III/A 42,5 N 0.50 4.3 3352
B1-Z3 CEM (35K/30S/35LL) 0.50 9.2 15132
B1-Z4 CEM (20K/30S/50LL) 0.50 16.4 48260
B1-Z5 CEM II/B-M (S-LL) 0.50 5.3 5022
B1-Z6 CEM II/C (50K/30S/20LL) 0.50 7.1 9012
1) 1d mould, 6d under water, 21d 20 °C/65 % r. H., 28d 2 Vol.-% CO2
34
Limit state carbonation – material parameters
Concrete Cement w/c xc [mm] 1) RACC-1
[(mm²/a)/(kg/m³)]
B0-Z1 CEM I 42,5 R 0.65 7.4 9790
B0-Z2 CEM III/A 42,5 N 0.65 11.5 23643
B1-Z1 CEM I 42,5 R 0.50 4.3 3260
B1-Z2 CEM III/A 42,5 N 0.50 4.3 3352
B1-Z3 CEM (35K/30S/35LL) 0.50 9.2 15132
B1-Z4 CEM (20K/30S/50LL) 0.50 16.4 48260
B1-Z5 CEM II/B-M (S-LL) 0.50 5.3 5022
B1-Z6 CEM II/C (50K/30S/20LL) 0.50 7.1 9012
1) 1d mould, 6d under water, 21d 20 °C/65 % r. H., 28d 2 Vol.-% CO2
35
Limit state carbonation – material parameters
Concrete Cement w/c xc [mm] 1) RACC-1
[(mm²/a)/(kg/m³)]
B0-Z1 CEM I 42,5 R 0.65 7.4 9790
B0-Z2 CEM III/A 42,5 N 0.65 11.5 23643
B1-Z1 CEM I 42,5 R 0.50 4.3 3260
B1-Z2 CEM III/A 42,5 N 0.50 4.3 3352
B1-Z3 CEM (35K/30S/35LL) 0.50 9.2 15132
B1-Z4 CEM (20K/30S/50LL) 0.50 16.4 48260
B1-Z5 CEM II/B-M (S-LL) 0.50 5.3 5022
B1-Z6 CEM II/C (50K/30S/20LL) 0.50 7.1 9012
1) 1d mould, 6d under water, 21d 20 °C/65 % r. H., 28d 2 Vol.-% CO2
36
Limit state carbonation – material parameters
Concrete Cement w/c xc [mm] 1) RACC-1
[(mm²/a)/(kg/m³)]
B0-Z1 CEM I 42,5 R 0.65 7.4 9790
B0-Z2 CEM III/A 42,5 N 0.65 11.5 23643
B1-Z1 CEM I 42,5 R 0.50 4.3 3260
B1-Z2 CEM III/A 42,5 N 0.50 4.3 3352
B1-Z3 CEM (35K/30S/35LL) 0.50 9.2 15132
B1-Z4 CEM (20K/30S/50LL) 0.50 16.4 48260
B1-Z5 CEM II/B-M (S-LL) 0.50 5.3 5022
B1-Z6 CEM II/C (50K/30S/20LL) 0.50 7.1 9012
1) 1d mould, 6d under water, 21d 20 °C/65 % r. H., 28d 2 Vol.-% CO2
37
Combine CO2 performance with lifetime durability parameters
0
10
20
30
40
50
60
0 20 40 60 80
Co
ncre
te s
usta
inab
ilty
(M
Pa x
a)/
(kg
CO₂)
Compressive strength MPa
XC3
Conrete sustainabilty in
(MPa x a) / (kg CO2) 1)
1) acc. to Haist et al: Ansatz zur Quantifizierung der Nachhaltigkeit von
Beton auf der Baustoffebene. In: Beton- und Stahlbetonbau 111 (2016),
Heft 10
Parameter 1 2 3
Cement --- CEM I CEM III/A CEM II/C
Clinker
intensitykg/(m3 x MPa) 7.2 2.8 2.7
Cement
contentkg/m3 280 320 320
w/c --- 0.65 0.50 0.50
fc,cube MPa 38.9 62.1 59.9
GWP CO2-eq/m³ 266 183 162
t to β = 0.5 a 53 133 57
1
3
2
38
Combine CO2 performance with lifetime durability parameters
0
10
20
30
40
50
60
0 20 40 60 80
Co
ncre
te s
usta
inab
ilty
(M
Pa x
a)/
(kg
CO₂)
Compressive strength MPa
XC3
Conrete sustainabilty in
(MPa x a) / (kg CO2) 1)
1) acc. to Haist et al: Ansatz zur Quantifizierung der Nachhaltigkeit von
Beton auf der Baustoffebene. In: Beton- und Stahlbetonbau 111 (2016),
Heft 10
Parameter 1 2 3
Cement --- CEM I CEM III/A CEM II/C
Clinker
intensitykg/(m3 x MPa) 7.2 2.8 2.7
Cement
contentkg/m3 280 320 320
w/c --- 0.65 0.50 0.50
fc,cube MPa 38.9 62.1 59.9
GWP CO2-eq/m³ 266 183 162
t to β = 0.5 a 53 133 57
1
3
2
39
Conclusions
▪ Durability of concrete structures today is ensured mostly by deemed to satisfy
(DTS)-rules for the concrete composition, concrete cover and the curing.
▪ DTS-rules (minimum cement content, maximum water-cement ratio, application rules on
cement etc.) have been established nationally, based on experience.
▪ This principle has proved successful in wide areas of building with concrete.
40
Conclusions
▪ Durability of concrete structures today is ensured mostly by deemed to satisfy
(DTS)-rules for the concrete composition, concrete cover and the curing.
▪ DTS-rules (minimum cement content, maximum water-cement ratio, application rules on
cement etc.) have been established nationally, based on experience.
▪ This principle has proved successful in wide areas of building with concrete.
▪ Reasons to differ from the descriptive procedure that is based on experience today:
- minimum service life >> 50 years is to be verified
- new building materials without long-term experience
- specific environmental conditions / stresses
▪ Performance to be validated depends on the application; e. g. indoor concrete vs.
severe exposure
41
Conclusions
▪ Specification of test requirements and assessment criteria for the proof of the durability
potential of concrete in laboratories / service life design:
- Reliable exclusion of cases that have demonstrably lead to damage
- No exclusion of well-tried and proven concrete constituents
respectively concrete mixes
42
Conclusions
▪ Specification of test requirements and assessment criteria for the proof of the durability
potential of concrete in laboratories / service life design:
- Reliable exclusion of cases that have demonstrably lead to damage
- No exclusion of well-tried and proven concrete constituents
respectively concrete mixes
▪ Strength can be used as a proxy for durability in some cases (e. g. carbonation)
▪ Clinker efficient cements like CEM II/C are at least fit for use in indoor and “normal”
outdoor concrete when the concrete composition is sufficient and help to lower the
carbon footprint of concrete
▪ Limit state calculations can be used to combine the CO2 performance with service life
related durability parameters of concrete
43
Acknowledgement
Thanks to the collegues of
VDZ
and in particular to
Wibke Hermerschmidt
Sebastian Palm
44
A member of ECRA
Average cement content vs. min. cement content (XC1)
46
0
50
100
150
200
250
300
350
400
AT BE CZ DK FI FR DE IE IT NL PT SK UK
min caverage c
ce
me
ntco
nte
ntin
kg
/m3
Average cement content vs. min. cement content (XC1)
47
0
50
100
150
200
250
300
350
400
0 100 200 300 400
minimum cement content in kg/m3
ave
rag
ece
me
ntco
nte
ntin
kg
/m3
FI
DK
NL
Fresh concrete temperature and consistency
400
450
500
550
600
650
700
0 15 30 45 60 75 90 105
[mm
]
time [min.]
B1 M2 10°C
B1 M2 20°C
B1 M2 25°C
B1 M2 30 °C
flo
wva
lue
Consistency of concrete B1 varies depending on the temperature unpredictably
between normal stiffening and significant liquefaction → not robust
Source: HeidelbergCement - NEWSLETTER TECHNIK | Nr. 18 | Oktober 201348
Paste content
Fresh concrete temperature and consistency
400
450
500
550
600
650
700
0 15 30 45 60 75 90 105
flo
wta
ble
sp
read
[mm
]
time [min.]
B3 M2 10°C
B3 M2 20°C
B3 M2 25°C
B3 M2 30°C
Paste contentConsistency of concrete B2
shows expected stiffening
as a function of temperature
→ robust
Source: HeidelbergCement - NEWSLETTER TECHNIK | Nr. 18 | Oktober 201349
Average cement content vs. min. cement content (XC1)
50
0
50
100
150
200
250
300
350
400
0 100 200 300 400
minimum cement content in kg/m3
ave
rag
ece
me
ntco
nte
ntin
kg
/m3
FI
DK
NL▪ Low minimum cement
content is not necessariliy
an incentive for low cement
content in practice
▪ Sufficient cement content
contributes to robust fresh
concrete properties
Average clinker content vs. min. cement content (XC1)
51
minimum cement content in kg/m3
avera
ge
clin
ker
conte
nt
in k
g/m
3
0
50
100
150
200
250
300
350
400
0 100 200 300 400
NL
DK
FI
ATPT
IT
▪ DK:
- mean c: 260 kg/m3
- clinker factor: 0,86
▪ FI:
- mean c: 340 kg/m3
- clinker factor: 0,82
▪ NL:
- mean c: 320 kg/m3
- clinker factor: 0,46
▪ Low minimum cement
content is not necessariliy
an incentive for low clinker
content in practice
▪ Different approaches
depending on availability of
materials
Average cement content vs. min. cement content (XF4)
53
0
50
100
150
200
250
300
350
400
0 100 200 300 400
minimum cement content in kg/m3
ave
rag
ece
me
ntco
nte
ntin
kg
/m3
DK*
▪ Low minimum cement
content is not necessariliy
an incentive fort low cement
content in practice
▪ Sufficient cement content
contributes to robust fresh
concrete properties
▪ Limiting the cement content
not a sufficient measure
* under severe and very severe conditions (e. g. XF3/XF4)
minimum fines content ≥ 375 kg/m3
Average clinker content vs. min. cement content (XF4)
54
minimum cement content in kg/m3
avera
ge
clin
ker
conte
nt
in k
g/m
3
0
50
100
150
200
250
300
350
400
0 50 100 150 200 250 300 350 400
DK*
NL
IT
AT
▪ DK:
- mean c: 260 kg/m3
- clinker factor: 0,86
▪ FI:
- mean c: 340 kg/m3
- clinker factor: 0,82
▪ NL:
- mean c: 320 kg/m3
- clinker factor: 0,46
▪ Low minimum cement
content is not necessariliy
an incentive for low clinker
content in practice
▪ Different approaches
depending on availability of
materials
* under severe and very severe conditions (e. g. XF3/XF4)
minimum fines content ≥ 375 kg/m3
Average clinker content vs. min. cement content (XC1/XF4)
55
minimum cement content in kg/m3
avera
ge
clin
ker
conte
nt
in k
g/m
3
0
50
100
150
200
250
300
0 100 200 300 400
XC1
XF4
DK DK
EU:
- mean cement content: 280 kg/m3
- mean clinker factor: 0.74
- mean clinker content: 209 kg/m3
FI
Average clinker content vs. min. cement content (XC1/XF4)
56
minimum cement content in kg/m3
avera
ge
clin
ker
conte
nt
in k
g/m
3
0
50
100
150
200
250
300
0 100 200 300 400
XC1
XF4
DK DK
EU:
- mean cement content: 280 kg/m3
- mean clinker factor: 0.74
- mean clinker content: 209 kg/m3
FI