Transcript 2012-06 Composite Cements - API Tests

Composite Cement
Testing Dyckerhoff
Germany
Denver, June 2012, Heiko Plack
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Test Programme
• Combinations tested (varying contents):
Cementitious component:
• API Class G
• API Class G + CEM I 42,5 N
• API Class H
(medium coarse cement, Blaine 3.100 cm2/g)
(medium fine cement, Blaine 3.900 cm2/g)
(coarse cement , Blaine 2.550 cm2/g)
Additive:
• Silica flour
• Medium fine
• Coarse
• Natural pozzolan
(Blaine 3.200 cm2/g)
(Blaine 1.000 cm2/g)
(very fine, Blaine 8.000 cm2/g)
 Variations include also changing water-to-cement/blend ratio = slurry density
 Blends were tested according to physical API Spec 10A requirements
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Components Involved
(Characterization)
Physical parameter
Component
Absolute
Density
g/cm
3
Fineness
Remarks
2
cm /g
Class G
3,17
3 110
Random Sample taken from DY production
CEM I 42,5 N
3,14
3 860
Random Sample taken from DY production
Class H
3,14
2 550
Random Sample taken from BU USA production
Silica flour, medium fine
2,65
3 230
Purchased (foreign source), SiO2 > 97%
Silica flour, coarse
2,66
1 000
Purchased (foreign source), SiO2 > 97%
Natural pozzolan (volcanic)
2,56
8 000
Purchased (foreign source), SiO2 > 97%
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Discussion Of Results
• Assumption (Dyckerhoff proposal): Standardization efforts target on
specifying a „basic“ cement, and not a „special cement“, e.g.
lightweight cement (covered by Lafarge NA proposal)
• = slurry density for performance testing is > 1.800 g/cm3
• Additives do affect the slurry density by
• their own absolute density differing from Portland cement
• higher specific surface area increasing the water demand
• = difficult to specify the water-to-cement/blend ratio, like for current
basic cements, G and H
• However, most important performance requirements identified as
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Free fluid (slurry stability)
Max. consistency 15 – 30‘ („rheology“)
Thickening time Schedule 5 („pumping time“)
Compressive strength 8h@140°F („later“ strength)
API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Discussion Of Results –
Conclusion
(I)
• Blends of different cement components (reactivity / fineness) + silica
flour of different fineness have been tested (+ a very fine natural
pozzolan)
• Apart from the content of used components the water-tocement/blend ratio has been varied respectively adjusted.
• It is evident that a cement manufacturer has sufficient degree of
freedom to adjust physical performance properties of a composite
cement by varying
• Cement type (reactivity)
• Additive fineness and content
• Water-to-cement/blend ratio
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Discussion Of Results –
Conclusion (II)
• Thus
• no maximum or mininim share of additive is to be specified,
• no water-to-cement ratio is to be specified,
• instead, a slurry density range is to be specified for performance testing
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Conclusion / Suggestion (I)
- Suggestion
Lafarge
NA
proposal
to specify two new API Spec 10A Composite Cement Classes with
the following physical requirements:
• Composite cement #1 (API Class E?) → Lafarge NA results / proposal:
• Additives: Pozzolanic (natural + artificial), list of materials to be defined!
• Slurry density for performance testing:
12,0 lb/gal < SG < 16,7 lb/gal
• Free fluid:
• API Schedule 5 thickening time:
TT > 90‘
• Max. consistency 15 – 30‘:
< 30 Bc
• Compressive strength 24h@100°F:
No chemical requirements to be specified for both new Classes!
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< 5,9%
API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
> 500 psi
Conclusion / Suggestions (II)
– Dyckerhoff
proposal
• Composite cement #2 (API Class F?) → Dyckerhoff results / proposal
• Considered as a „basic cement“
• Additives: Silica flour + Pozzolans
• Slurry density for performance testing:
• Free fluid:
• API Schedule 5 thickening time:
• Compressive strength 8h@140°F:
15,0 lb/gal < SG < 16,7 lb/gal
< 5,9%
90‘ < TT < 120‘ (130‘?)
> 1.000 psi
No chemical requirements to be specified !
However, classification as HSR grade possible if
- Portland clinker used complies with HSR requirements of Classes G/H
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Conclusion / Suggestions (III)
• Specifying slurry density requires a reference to API RP 10B for the
test method. Mud balances usually available at all cement
manufacturer‘s labs, calculation from absolute densities of
components may also be considered.
• Requirement to provide test report along with any order shall state:
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Slurry density at which performance tests were conducted
Water-to-cement/blend ratio at which performance tests were conducted
Share of Portland cement respectively of additive
Type of additive (silica flour, fly ash, natural pozzolan)
+ results of physical testing as specified (see above)
Chemical specification ???
API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012
Test Results
API Spec 10 A - Results
Thickening Time Test
API Schedule#5, 356bar, 52°C
Component, %
Com m ents
CEM I
24,5 R HSR
Slurry
density,
lb/gal
Free Fluid,
%
TT(Bc=100)
min
8h @ 38°C
psi
8h @ 60°C
psi
2,1
15
106
517
1.990
15,79
2,6
2
113
584
2.274
0,44
15,67
1,9
25
106
390
1.284
26
0,42
15,77
1,8
22
96
420
1.530
26
0,40
15,92
1,1
20
93
411
1.474
0,41
15,84
6,6
7
112
0
0,44
15,91
3,2
11
102
690
2.410
5
26
0,44
15,57
2,1
15
116
425
1.630
64
10
26
0,44
15,57
1,6
25
88
570
1.780
C3
59,6
14,4
26
0,44
15,57
1,6
22
80
580
1.790
C4
60
10
30
0,44
15,52
1,8
14
108
460
1.550
A3
100
0
0,44
15,92
2,1
17
98
653
2.387
D2
70
30
0,44
15,49
0,4
25
95
400
860
D3
60
40
0,67
13,77
1,8
7
110
too low
too low
0,38
16,70
5,1
13
110
1004
2.528
SF II
"coarse"
Nat.
pozz.
Test #
Class G
A1
100
0
0,44
15,92
B2
90
10
0,44
B3-0
74
26
Class G (med. coarse)
+ medium fine SF
w ater-to-cement ratio +/-
B3-1
74
B3-2
74
Class G (med. coarse cem.) + coarse SF
B3-3
74
A2
100
C1
69
C2
Class G (med. coarse cem.)
+ medium fine SF +/-
Class G (med. coarse cement)
+ CEM I 42,5 N (med. fine cement) +/+ med. fine SF +/-
Class G (med. coarse cem.)
+ natural pozzolan (very fine) +/Class G (med. coarse cem.)
+ nat. pozz, w /c +
Class H (coarse cem.)
+ medium fine SF +/-
Compressive strength
Consistency
after 30 min,
Bc
Class H
SF I
"m edfine"
Mix
w ater,
% BWOB
26
1.467
E1
100
E2
74
26
0,38
16,33
3,1
29
92
794
1.882
E3
74
26
0,4
16,11
4,6
8
117
596
1.473
E4
74
26
0,44
15,71
4,3
14
141
not enough sample
Min (excl. Test# D3 = lightw eight cem ent)
59,6
5
74
0
26
0
0,38
15,49
0,4
2
80
390
860
Max (excl. Test# D3 = lightw eight cem ent)
100
14,4
100
30
26
40
0,44
15,86
6,6
29
141
1004
2528
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API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012