durability of portland limestone cement - mcgill...
TRANSCRIPT
Cement
Durability of Portland yLimestone Cement
Anna Maria Workshop XII November 2011November 2011
ContentIs the durability of PLC
Wh did l k ?
ysimilar to PC*?
What did we look at?
Scaling and Freeze-thawField experience• Field experience
• “Robustness Testing”
Chloride Ion PenetrationChloride Ion Penetration
ASR
Sulfate Resistance @ 23C Sulfate Resistance @ 23C
Carbonation
D i Sh i k Drying Shrinkage
*PLC - Portland Limestone Cement, PC - Portland Cement
2
,GUL - General Use Limestone Cement, GU - General Use Cement
November 10 2011
Robustness Testing - Scaling and Freeze/Thaw
Objective: Assess the sensitivity of PLC compared to PC when
subjected to extreme conditions
Scaling Water/Binder ratio of 0 45 0 50 and 0 55 Water/Binder ratio of 0.45, 0.50 and 0.55
Lab and field testing
25% FA* d 35% l 25% FA* and 35% slag
Freeze-ThawFreeze Thaw Water/Binder ratio of 0.74, 0.80 and 0.90
20% FA* and 35% slag
3
20% FA and 35% slag
FA* - Type F November 10 2011
Scaling – Lab Results - ASTM C672g
1.00T i l li it f ASTM C672
0.70
0.80
0.90 Typical limits for ASTM C672: between 0.8 and 1.0 kg/m2
0.50
0.60
0.70
ss, k
g/m
2
0.450.5
0.20
0.30
0.40Los
0.55
0.00
0.10
0.20
GU GUL GU + 25%FA
GUL + 25%FA
GU + 35%Slag
GUL + 35%Slag
• Lab scaling results tend to indicate impact of w/c
4
No measurable difference between GU and GULNovember 10 2011
Scaling – Field Tests
5November 10 2011
Scaling - Field results
after 1 year (only showing the FA slabs)
No significant difference between GUbetween GU and GUL
6November 10 2011
Scaling – Field Trials
Three field trials concluded; Good performance of GUL with up to 50% SCMp p
No significant difference between GU and GUL mixes
After 2 wintersPLC + 25% SCM
Parking lot in Gatineau
PC +
Anna Maria workshop X (2009)
Concrete International (2010)
PLC + 50% SCM
25% SCM(2010)
+ 2 Paving projects - Brookfield and Exshaw
Journal of Pavement and Research Technology (2010)
7
PC + 50% SCMSCM - Optimized blend of slag and C ash November 10 2011
Freeze-ThawC666-A
• Durability Factor good• Little expansion…Little expansion…• …. but scaling of the bars, especially with the higher W/C (see next slide)( )
No measurable differencebetween GU and GUL
8
between GU and GUL
November 10 2011
Freeze-ThawC666 AC666-A
9No significant difference between GU and GUL
November 10 2011
Chloride Penetration – RCPT – Field Samples
4000PC at 28 days
mbs
)3000 PLC at 28 days
PC at 56 daysPLC at 56 days(C
oulo
m
2000PLC at 56 days
Pas
sed
1000 28d56dC
harg
e
00 10 20 30 40 50 60
SCM Replacement Level (%)p ( )
No measurable difference between PC and PLC
10
Results from Gatineau Trial (Concrete International, Jan 2010)SCM - Optimized blend of slag and C ash
November 10 2011
Chloride Penetration Profiles - Field Samples
1.0
1.2PC -0% SCMPLC-0% SCMon
cret
e)
0.8
PLC 0% SCMPC -25% SCMPLC -25% SCMas
s of
co
0.4
0.6 PC -50% SCMPLC -50% SCM
(% b
y m
0.2
Chl
orid
e
0.00 5 10 15
Depth (mm)
C
Chloride Profiles for Cores taken at 35 Daysand Immersed in NaCl solution for 42 Days
No measurable difference between PC and PLC
11
and Immersed in NaCl solution for 42 DaysResults from Gatineau Trial (Concrete International, Jan 2010)SCM - Optimized blend of slag and C ash
November 10 2011
ASR – Concrete Prism Test 38ºCExpansion, % Expansion %
0.17
0.2Control30% Slag40% Sl
Expansion, % Expansion, %
Control20% Fly Ash
0.1440% Slag50% Slag
GU
25% Fly Ash30% Fly Ash
GU
0.08
0.11___------ GUL
___ GU------ GUL
0.05
-0.01
0.02
0 100 200 300 400 500 600 700 800 0 100 200 300 400 500 600 700 800
Exposure, days
0 100 200 300 400 500 600 700 800 0 100 200 300 400 500 600 700 800
No significant difference between GU and GUL
12
gSimilar results for concrete prism tests @ 60ºC and mortar bar tests (see next 2 slides)
F ash November 10 2011
ASR - Concrete Prism Test 60CExpansion, %
0 20Expansion, %
Control20% Fly Ash25% Fly Ash
___ GU------ GUL0.17
0.20Control30% Slag40% Slag50% Sl
___ GU------ GUL
5% y s30% Fly ash
0.14
50% Slag
0.11
0.08
0 02
0.05
-0.01
0.02
13Exposure, days
0 100 200 300 4000 100 200 300 400
F ash November 10 2011
ASR - Accelerated Mortar Bar Test
0 8Expansion, % Expansion, %
0.7
0.8Control30% Slag40% Slag
Control20% Fly Ash25% Fly Ash
0.650% Slag
___ GU------ GUL
30% Fly Ash
___ GUGUL
0.4
0.5------ GUL ------ GUL
0.3
0 1
0.214dlimit 14d limit
0
0.1
0 5 10 15 20 25 30 0 5 10 15 20 25 30
14
0 5 10 15 20 25 30
Exposure, days
0 5 10 15 20 25 30
F ash November 10 2011
Carbonation – 1 year resultsCarbonation Depth, mmMix - w/c 0.45 1d curing 3d curing 7d curingGU 5 2 1GUL 5 2 1GU + 40% FA 11 5 5GUL + 40% FA 10 5 5GU + 60% Slag 9 5 4GUL + 60% Slag 10 3 3
Mix - w/c 0.55GU 7 4 2GUL 7 4 3GU + 40% FA 15 10 7GUL + 40% FA 15 10 10GU + 60% Slag 15 8 7GUL + 60% Slag 15 10 8
Curing, w/b ratio and SCMs had an impact on carbonation depth
N i ifi t diff b t GU d GUL
15Samples kept at 23ºC – 65% RH
No significant difference between GU and GUL
November 10 2011
Carbonation – 1 year results- 0.55 w/b
- 3d curingGU GUL
GU + GUL +GU +40% FA 40% FA
GU + GUL +GU 60% Slag
GUL 60% Slag
16No significant difference between GU and GUL
November 10 2011
Mortar Drying Shrinkage ASTM C596
0Shrinkage, %
3d moist curing
GU-0.04
-0.02
GUGULGU + 30% FAGUL + 30% FA
-0.06GUL + 30% FAGU + 50% SlagGUL + 50% Slag
-0.08
-0.12
-0.1
Drying, days
0 5 10 15 20 25 30
17
No significant difference between GU and GULNovember 10 2011
Sulfate Resistance C1012 @ 23C
Fly Ash Mixes Standard C10120.18
0.2
GUGULStandard C1012
23C
0.14
0.16
0.18 GULGU + 15% FAGUL + 15% FAGU + 20% FAGUL + 20% FA
0.1
0.12
pans
ion,
%
GU + 25% FAGUL + 25% FAGU + 35% FAGUL + 35% FA
0.06
0.08Exp
0
0.02
0.04
00 6 12 18 24 30 36 42 48 54 60 66 72 78
Exposure, weeks
• Also tested with slag, SF and ternary systems @ 23C - All mixes show little expansion (< 0.1%) after 18 months of exposure, except for the control mixes (GU and GUL)
18
( 0 %) a te 8 o t s o e posu e, e cept o t e co t o es (GU a d GU )
No measurable difference between GU and GULFA* - Type F November 10 2011
SSummary
There is no measurable difference between PLC and PC, with respect to durability in the following areas;
Scaling
Freeze/thaw
Chloride ion penetration
ASR
Carbonation
Shrinkageg
Sulfate resistance @ 23C
19November 10 2011