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TRANSCRIPT
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I i i fInvestigation of C t A tConcrete Aggregate f Alk li C b tfor Alkali-Carbonate
ReactionReaction
AAR Reactions2
AAR Reactions are chemical reactions between theAAR Reactions are chemical reactions between the cement and the aggregate causing the concrete to deteriorate.
There are two AAR reactions based on the reactive mineral type:Alkali Silica Reaction (ASR) with unstable forms ofAlkali-Silica Reaction (ASR) with unstable forms of silica (most common)Alkali-Carbonate Reaction (ACR) with certainAlkali Carbonate Reaction (ACR) with certain dolomite textures (least common)
Both are destructive, are not mutually exclusive, and under the right conditions cyclic.
This presentation is focusing on ACR.
Why investigate for a Why investigate for a “uncommon” reaction?“uncommon” reaction?
3
“uncommon” reaction?“uncommon” reaction?ACR cannot be mitigated for. The addition of fly ash, g y ,GGBFS, or silica fume do nothing to stop the reaction. It requires only a little alkali to start the reactionO th ti i t t d it d t t til llOnce the reaction is started, it does not stop until all aggregates have reacted destroying the concrete.It is the hardest reaction to identify when investigatingIt is the hardest reaction to identify when investigating an affected structure because its byproduct, brucite is very difficult to find even by microscopic examination. It does not have clear cut evidence like ASRIt does not have clear cut evidence like ASR. If reactive minerals for both ASR and ACR are present, both reactions are occurring and eventually the g ypresence of the silica gel will obscure any evidence of ACR.
Chickamauga LockChickamauga Lock
4
1937-39-Spillway deck poured 1999
Chickamauga LockChickamauga Lock
p y p1941-Lock and Dam completed1946-Cracking is a problem1963 petrographic-no silica gel or brucite found
1999
1963 petrographic-no silica gel or brucite found1970 petrographic-”AAR reaction definitelyoccurring”, no byproduct1993 94 t hi1993-94 petrographics-positive identification of silica gelg1996 petrographic-silica gel and brucite identified1997 petrographics-only1997 petrographics only found silica gel
Pre-1957
Chickamauga Chickamauga 5
PetrographicsPetrographicsReview of the 1930’sReview of the 1930 s petrographic examination of the aggregate showed 4-25% chert AND 5-32% dolomitechert AND 5-32% dolomite rhombs with 10-41%insoluble residue matrix. The right mineral compositions for bothmineral compositions for both ASR AND ACR. From the lack of by product for the first 25 years of expansion, it is logical to assume the ACR started first.
Definition6
The Alkali-Carbonate Reaction is a chemical reaction between hydroxyl y y
ions associated with the alkalis sodium and potassium in the cement pand certain dolomitic textures in the aggregate resulting in expansion and gg g g peventually cracking of the hardened
concrete.
Conditions Required Conditions Required 7
for ACRfor ACRAlkali Content in the concrete
The industry limit for Equivalent Alkalies in cement is 0.6% which is NOT low enough to stop ACR. Research has indicated the cement alkali content would need tohas indicated the cement alkali content would need to be lower than 0.4% and still be combined with other preventative measures to suppress the reaction.Alkalis may come from other sources than just cementAlkalis may come from other sources than just cement such as cementitious materials, aggregates (feldspars), local water, soil, or deicing agents (Potassium Acetate)(Potassium Acetate).A free alkali content of 2.0 kg/m3 or 0.12 lbs/ft3 in the concrete is normally sufficient to allow a reaction.ACR i li ti hi h it t t itACR is a cyclic reaction, which means once it starts it can generate it’s own (Na, K, Li) OH to continue the reaction.
Reactive AggregateReactive Aggregate8
Dolomite / Dolomitic Limestone –10 to 85% dolomite and 5-50% insoluble residue.Specifically dolomite rhombohedra crystals in a fine grained matrix of calcitecrystals in a fine grained matrix of calcite and insoluble residue (clay and silica). A pore structure that allows alkali solutionA pore structure that allows alkali solution to penetrate the rock
ACR Reactive TextureACR Reactive Texture9
Doloomitte
RRhom Matrix
Insoluble Residue m
bsPlain Light 63X Cross Nichols Light 63X
MatrixResidue
ACR ReactionACR Reaction10
1) CaMgCO3 + 2(Na,K)OH Mg(OH)2 + CaCO3 + (Na,K)2CO3
Dolomite + Alkali Brucite + Calcite + Alkali H d id C b tHydroxide Carbonate
2) (Na,K)2CO3 + Ca(OH)2 2(Na,K)OH + CaCO3
Alkali + Cement Alkali + CalciteAlkali + Cement Alkali + CalciteCarbonate Hydration Hydroxide
(Portlandite)
3) Repeat first reaction
LiOH also causes expansion but not at the rate that NaOH and KOH does.
BruciteBrucite11
Photomicrograph of crack, partially filled with brucite, from ACR g p , p y ,deterioration of impure dolomitic limestone aggregate in a pre-stressed concrete. Crack runs through fossiliferous carbonate particle into cement paste on right. The brownish-
ll d it i l ftyellow deposit in left side of crack is brucite. Blue sections of crack are filledof crack are filled with blue epoxy for clarity. Field width approximately 4.8 mm.
Used courtesy of Steven J. Stokowski, Jr. and Janet Sarson of Stone Products Consultants
approximately 4.8 mm. Plane polarized light.
Early vs. Late Early vs. Late 12
ExpandersExpandersEarly Expanders - dolomite rhombohedra crystalsEarly Expanders dolomite rhombohedra crystals floating in a fine grained matrix of calcite and insoluble residue (clay and silica). The calcite to dolomite ratio is approximately 1 to 1 with 5 to 25% insoluble residue. The
ti ll h i ith i th fi t 5reaction usually shows expansion with in the first 5 years of the project.
Late Expanders – has more or larger dolomite crystals so the crystals interlock, decreasing the calcite/clay/silica matrix and slowing down the reaction. Matrix also is not as fi i d i h E l E d Th d l ifine grained as in the Early Expanders. The dolomite content is 75 to >90% of the soluble content and the rock contains 10 to 25% calcite and 21 to 49% insoluble material The Calcite:Dolomite ratio is between 0 14:1 andmaterial. The Calcite:Dolomite ratio is between 0.14:1 and 0.36:1. These can take 10 to 20 years before expansion shows in the project.
Potential Early vs. Later ExpanderPotential Early vs. Later Expander13
ThinThin sections
were stainedstained,
the calcite
accepts the stain while thewhile the dolomite does not,
so theso the pink is calcite.63X 63X
AlkaliAlkali--Silica and AlkaliSilica and Alkali--Carbonate Reactive AggregateCarbonate Reactive Aggregate
14
gg ggg g
te
sD
olom
itR
hom
bsD R
ble
aU
nsta
bSi
lica
Plain Light 63X Cross Nichols Light 63X
Late ExpandersLate Expanders15
pp
It is much more difficult to distinguish between Late Expanders and non-reactive Dolomite rocks. There has even been some dolomite rock with nohas even been some dolomite rock with no limestone and very little clay/silica that have expanded. All occurrences of carbonate rock that have been found to be reactive have portions of the dolomite rhomb texture. However, not all dolomitic ,limestones with this texture expand with sufficient force to cause distress.There have been many structures built out of goodThere have been many structures built out of good dolomite aggregate.
Determining if your Determining if your aggregate is potentially aggregate is potentially
16
gg g p ygg g p yreactivereactive
Sampling the aggregateSampling the aggregateProcure a good map of the quarry to be able to judge the overall quality of the quarry andjudge the overall quality of the quarry and determine is selective quarrying is required.Best if possible to test a core or cores from theBest if possible to test a core or cores from the quarry. Ledge rocks are difficult to collect and to ensure full coverage of the quarry.g q yTake the petrographic samples and the samples for the ASTM C 586 tests from the same sample/location. This way there is good correlation between the two tests.
ACR TestsACR Tests17
ACR TestsACR Tests
1) ASTM C 295 P t hi E i ti1) ASTM C 295 Petrographic Examination2) ASTM C 586 Potential Alkali Reactivity of Carbonate Rocks for Concrete Aggregate (Rock Cylinder Method)3) ASTM C 1105 Length Change of Concrete Due to Alkali-Carbonate Rock Reaction
ACR Tests on Cores or ACR Tests on Cores or Ledge RocksLedge Rocks
18
Ledge RocksLedge Rocks
ASTM C 295 Petrographic – determines the amount of reactive minerals and textures in aggregate.ASTM C 586 Potential Alkali Reactivity of C b t R k 11/32 i h di tCarbonate Rocks – a 11/32 inch diameter by 1-3/8 inch long rock cylinder is cored out of the ledge rock and soaked in NaOHout of the ledge rock and soaked in NaOH at room temperature for 1-12 months.
Petrographic TestPetrographic Test19
g pg p
1) X-ray diffraction will determine amount of dolomite, calcite, and insoluble reside in the sample but cannot determine the typethe sample but cannot determine the type or texture.2) Microscopic Thin Sections (25-30µm)will determine type and texture of thewill determine type and texture of the dolomite, calcite, and insoluble residue in the aggregate.3) Ultra-Thin Thin-Sections (10-15 µm) to accurately discern the reactive texture since most of the dolomite rhombs are 25µm or less.
ACR Petrographic ACR Petrographic Prediction DiagramsPrediction Diagrams
20
Prediction DiagramsPrediction Diagrams2 diagrams use chemical composition of the rock to2 diagrams use chemical composition of the rock to predict potential ACR expansion.
Canadian Standards
CaO: MgO RATIO VERSES INSOLUBLE RESIDUE PERCENTAGE FOR A SUITE OF ALKALI-CARBONATE REACTIVE AND NON-REACTIVE CARBONATE ROCKS (CSA A23.2-26A & C.A. Rogers, “Evaluation of the Potential for Expansion and Cracking of Concrete Potentially Reactive Carbonate Rock Progress
R t #2 “St t id S f R ti C b t
Potentially Alkali Carbonate Reactive Rocks
Canadian Standards Association CSA A23.2-26A Virginia Council of Highway
Investigation and Research
200
100
50
p gCaused by the Alkali-Carbonate Reaction”, Figure 8)
AGGREGATES CONSIDERED NON-EXPANSIVE
Report #2 “Statewide Survey for Reactive Carbonate Aggregates” by W. Cullen Sherwood and Howard H. Newlon, Jr.; Virginia Council of Highway Investigation and Research; Feb. 1964.
CaO
: M
gO R
ATI
O
20
10
5
AGGREGATES CONSIDERED POTENTIALLY EXPANSIVE
2
21
2
2
0 5
2
1
55
50 45 40 35 30 25 20 15 10
INSOLUBLE RESIDUE IN PERCENT
AGGREGATES CONSIDERED NON-EXPANSIVE
Known ACR expanders have been plotted in this area.
1
1
2
1
Known ACR ExpandersKnown ACR Expanders
21
CaO:MgO RATIO VERSES INSOLUBLE RESIDUE PERCENTAGE FOR A SUITE OF ALKALI-CARBONATE REACTIVE AND NON-REACTIVE CARBONATE ROCKS (CSA A23.2-26A & C.A. Rogers, “Evaluation of the Potential for Expansion and Cracking
of Concrete Caused by the Alkali-Carbonate Reaction”, Figure 8) C S S
200
100
Known Alkali-Carbonate Reactors – ASTM STP 169D-pg. 414, Table 1K - Kingston, Ontario; I - Iowa, Illinois, & Indiana; VE - Virginia-Early; G - Gull River; Virginia-Late
AGGREGATESCONSIDERED
STP 169B Dolar-Mantuani, pg.733 STP 169D Milanesi, pg. 413 STP 169D Hilton, pg. 416 Very reactive 0.275/14wks
TIO
50
CONSIDERED NON-EXPANSIVE
AGGREGATES
D-M Very slow reaction took 40 wks Progress Report #7b, Hilton, 1968 Very reactive-1.21-1.05/21wks Medium reactive-0.97/21wks Slow reaction – 0.12/21 wks Table IV, pg. 25
CaO
: M
gO R
AT
20
10
AGGREGATES CONSIDERED POTENTIALLY
EXPANSIVE
Highway Research Record # 45, Lemish and Moore, 1964 Table 2, pg. 61 Very reactive-1.2/21wks Medium reactive-0.8/21wks Slow reactive-0.5-0.2/21wks
VE15
2
55
K1 K2I1 I2
I3 I4
VE2
VE4G1 G2G3 G4
VE3
0 5
2
1
50 45 40 35 30 25 20 15 10
INSOLUBLE RESIDUE IN PERCENT
AGGREGATES CONSIDERED NON-EXPANSIVE G3 G4
VL
Limestone QuarryLimestone Quarry
22
CaO : MgO RATIO VERSES INSOLUBLE RESIDUE PERCENTAGE FOR A SUITE OF ALKALI-CARBONATE REACTIVE AND NON-REACTIVE CARBONATE ROCKS (CSA A23.2-26A & C.A. Rogers, “Evaluation of the Potential for Expansion and Cracking of Concrete Caused by the Alkali-
40 3
34
4b 5
7
19
22 9
200
100
p g yCarbonate Reaction”, Figure 8)
AGGREGATESCONSIDERED
LEGEND Sample Numbers
37
38
1
2
16 218b10
Bench 1
Bench 2TIO
50
CONSIDERED NON-EXPANSIVE
AGGREGATES
25
4, 31, a1
37
15
1
30
8Bench 2
CaO
: M
gO R
AT
20
10
AGGREGATES CONSIDERED POTENTIALLY
EXPANSIVE
Aggregates with Late Expander Chemistry
b1
3635
32 33
30
4a 17 8a20
26 5
2
55
y
39
0 5
2
1 50 45 40 35 30 25 20 15 10
INSOLUBLE RESIDUE IN PERCENT
AGGREGATES CONSIDERED NON-EXPANSIVE (several known ACR expanders have been plotted in this area)
Dolomite QuarryDolomite Quarry23
CaO:MgO RATIO VERSES INSOLUBLE RESIDUE PERCENTAGE FOR A SUITE OF ALKALI-CARBONATE REACTIVE AND NON-REACTIVE CARBONATE ROCKS (CSA A23.2-26A & C.A. Rogers, “Evaluation of the Potential for Expansion and Cracking of Concrete Caused by the Alkali-
LEGENDBench 1Bench 2
Bench 3Benches 1 & 2
200
100
Potential for Expansion and Cracking of Concrete Caused by the AlkaliCarbonate Reaction”, Figure 8) FLORIDA ROCK QUARRY
AGGREGATESCONSIDERED
Sample Numbers
2 9 11 22
1, 12, 13 19
16
Bench 3Bench 4
TIO
50
CONSIDERED NON-EXPANSIVE
7, 24
5, 8, 17, 23
2, 9, 11, 22
3, c2
16
CaO
: M
gO R
AT
20
10
AGGREGATES CONSIDERED POTENTIALLY
EXPANSIVE
b2
a2
c14
5
55 Sample with Late Expander
a1
1
b1
0
AGGREGATES CONSIDERED NON-EXPANSIVE (several known ACR expanders have plotted in this area) 15 10 14 18 25
5
2
50 45 40 35 30 25 20 15 10
INSOLUBLE RESIDUE IN PERCENT
Chemistry
Known ACR ExpanderKnown ACR Expander24
pp
Potentially Reactive Carbonate Rock Progress
Potentially Alkali Carbonate Reactive Rocks
Known Alkali-Carbonate Reactors – ASTM STP 169D – pg. 414, Table 1 Kingston, Ontario – Early ExpanderIowa, Illinois, & Indiana – Early Expander Virginia – Early Expander G ll Ri O i L E d Potentially Reactive Carbonate Rock Progress
Report #2 “Statewide Survey for Reactive Carbonate Aggregates” by W. Cullen Sherwood and Howard H. Newlon, Jr.; Virginia Council of Highway Investigation and Research; Feb. 1964.
Gull River Ontario – Late ExpanderVirginia – Later Expander
STP 169D Milanesi’s Expander – pg. 413 STP 169B Dolar-Manuani, pg. 733
Very reactive 0 275/14 wksSTP 169D Hilton pg. 416
Very Reactive-1.21-1.05/21 wks
Very reactive 0.275/14 wks Very slow reaction, took 40 wks
Progress Report 7b, Hilton, 1968
Medium Reactive-0.97/21 wksSlow Reaction – 0.12/21 wks Table IV Pg 25
2
2
Table IV, Pg. 25
Highway Research Record #45 Lemish and Moore, 1964 Table 2, pg. 61 Very Reactive-1.2/21 wks
Known ACR expanders have 1
2
1
12
Medium Reactive-0.8/21 wks Slow Reactive-0.5-0.2/21wks
been plotted in this area. 1
16
Limestone QuarryLimestone Quarry25
Potentially Reactive Carbonate Rock Progress Report #2 “Statewide Survey for Reactive Carbonate Aggregates” by W. Cullen Sherwood and Howard H Newlon Jr ; Virginia Council of Highway
Potentially Alkali Carbonate Reactive Rocks# - core sample number that has potential for expansion or plots differently than the majority of passing samples
core sample that does not exceed limit of expansion H. Newlon, Jr.; Virginia Council of Highway Investigation and Research; Feb. 1964.
or # - Bench 1
or # - Bench 2
Sample with Late Expander Chemistryp p y
2
2
2
Known ACR expanders have been plotted in this area
1
2
1
1
8
21 8b
20 36
been plotted in this area.1
31a14
1530
32 334a17
b1
2635
39
Dolomite QuarryDolomite Quarry26
Potentially Reactive Carbonate Rock Progress Report #2 “Statewide Survey for Reactive Carbonate Aggregates” by W. Cullen Sherwood and Howard H Newlon Jr ; Virginia Council of Highway
Potentially Alkali Carbonate Reactive Rocks# - core sample number that has potential for expansion or plots differently than the majority of passing samples
core sample that does not exceed limit of expansion H. Newlon, Jr.; Virginia Council of Highway Investigation and Research; Feb. 1964. Bench 1
Bench 2Benches 1 & 2Bench 3Bench 4Bench 4
2
2
2
Known ACR expanders have been plotted in this area
10
c1 3a1
b1a2
b2
c2
4
2
2
1 11
been plotted in this area.
251131812
4
16 19 21 20
6
1
Petrographic Exam Petrographic Exam ––27
Thin SectionsThin Sections
When having the thin sections prepared, get half of the slide stained p p , gwith red, this allows for very easy identification of the calcite and dolomite.Thin sections should be prepared forThin sections should be prepared for all samples in the questionable zones of the ACR Prediction Diagramsof the ACR Prediction Diagrams
Limestone Quarry #36Limestone Quarry #36ACR & ASR R ti T tACR & ASR R ti T t
28
ACR & ASR Reactive TextureACR & ASR Reactive TexturePPL XN PPL 25X 25X
Limestone Quarry #10 &14 Limestone Quarry #10 &14 Less or NonLess or Non Reactive TexturesReactive Textures
29
Less or NonLess or Non--Reactive TexturesReactive Textures
#10 63X#10 63X PPL
Slight gtexture along a stylolite
# 14 63X
stylolite
63X PPL
NoNo ACR
texture
Dolomite Quarry #4 Dolomite Quarry #4 Reactive TextureReactive Texture
30
Reactive TextureReactive Texture
PPL XN 63XPPL 63X
XN 63X
Dolomite Quarry #12&13 Dolomite Quarry #12&13 NonNon--reactive Texturesreactive Textures 31
These had the
chemistry of late
expanders;expanders; from the
texture, it is stillstill
possible but unlikely, the texture
appears stable.
XN 63X
PPL 25X
stable.
Dolomite Quarry #18Dolomite Quarry #18--32
Late Expander TextureLate Expander TextureUltra-thinUltra thin
Thin section, it has been stained thestained, the slight pink tint is the
calcite disseminated
among theamong the dolomite
XN 63X
ASTM C 586 Rock ASTM C 586 Rock 33
Cylinder MethodCylinder Method586 samples should be chosen from the core after586 samples should be chosen from the core after petrographic results (at least the x-ray) is completed. Corresponding expansion from a 586 co p eted Co espo d g e pa s o o a 586with a reactive petrographic result will provide the best analysis of a quarry. Sampling from the ledge wall or the shotrock before the petrographics have been completed
fdoes not allow for good correlation between the tests. No matter how hard one attempts to match the shotrock/ledge rocks samples to the cores itthe shotrock/ledge rocks samples to the cores, it is never a sure match.
ASTM C 586 ASTM C 586 34
Sample PreparationSample PreparationEnsure test 0.8
0.9
cylinders have good smooth endpoints or
0.5
0.60.7
0.8
h endpoints or the data will be erratic and
0 1
0.2
0.3
0.4
ge in
Len
gth
wrong.
Th l-0.2
-0.1
00.1
Perc
ent C
han
These samples had their point reground after
0 6
-0.5-0.4
-0.3P
68 days in NaOH, early
data was lost.
-0.7
-0.6
0 50 100 150 200 250
Number of Days in NaOH
Aggregate TestsAggregate Tests35
gg ggg g
ASTM C 1105 Determination of Length Change of Concrete g gdue to ACR – concrete mortar bar is stored in high humidity at 73o F for one year. Job concrete mix is used so the alkali content is what would be in the job.ASTM C 1293 D t i ti f L th Ch f C tASTM C 1293 Determination of Length Change of Concrete due to ASR – concrete mortar bar with high alkali cement is stored in high humidity at 100o F for one year. Extra alkali is added to force reaction May be modified by decreasingis added to force reaction. May be modified by decreasing alkali, adding supplemental cementitious materials, or using the job mix.Despite the titles ASTM C 1105 and ASTM C 1293 cannotDespite the titles ASTM C 1105 and ASTM C 1293 cannot distinguish between ACR and ASR if the mineralogy is present for both reactions.If both mineralogies are present the theory is to run theIf both mineralogies are present, the theory is to run the test with sufficient cementitious materials to suppress the Alkali-Silica Reaction and thereby determine if the aggregate is also Alkali-Carbonate Reactive.
Preparations for Preparations for 36
ASTM C 1293/1105ASTM C 1293/1105
Because 1293 is run at 100oF and 1105 is tested at 73oF, 1293 is the harsher test; therefore running ASTM C 1293 should give a g gbetter estimate of the potential reactivity of an aggregate whether it is ASR or ACR. Federal Highway Administration recommendsFederal Highway Administration recommends the modified ASTM C 1293 be run for 2 years; therefore, these tests need to be planned in advance.Criteria for the two year test is a combination of 1105 and 1293 - <0.015/3mon; <0.025/6mon; <0.03/1yr; <0.04/2yr.<0.03/1yr; <0.04/2yr.
ACR Mitigation for ACR Mitigation for 37
New StructuresNew Structures
Avoid use of aggregate classified as potentially reactive by selective quarrying.Specify the use of low alkali cement andSpecify the use of low alkali cement and cementitious materials in the hope of keeping the alkali content of the concrete low enough the reaction will not start (< 2 kg/m3)the reaction will not start (< 2 kg/m3).Dilute so the amount of potentially reactive rock is less than 20% of the coarse or fine aggregate or 15% of the total if reactive material is present in both.Specify the minimum aggregate size that isSpecify the minimum aggregate size that is feasible for the project.
What to do if the What to do if the 38
aggregate is reactive.aggregate is reactive.
Hope it is a late expander andThat you have already retiredThat you have already retired.
Th l thi th t b d thThe only thing that can be done then is slot cutting to release the
i i th t iexpansion pressure in the concrete in the hopes of preventing cracking.
ReferencesReferences
39
ReferencesReferencesASTM STP 169B (1978), C (1994), and D (2006)E l ti f th P t ti l f E i d C ki f C t C d b Alk li C b tEvaluation of the Potential for Expansion and Cracking of Concrete Caused by Alkali-Carbonate Reaction, C. A. Rogers, 1986Virginia Council of Highway Investigation and Research Potentially Reactive Carbonate Rocks Progress Report #2 Statewide Survey for Reactive Carbonate Aggregates, W. C. Sherwood, H. Newlon, Jr., 1964Ontario Division of Mines Industrial Mineral Report 42 L Dolar Mantuani 1975Ontario Division of Mines, Industrial Mineral Report 42, L. Dolar-Mantuani, 1975Handbook of Concrete Aggregate, L. Dolar-Mantuani, 1983ACI 221.1R-98CSA A23.1-00/A23.2-00 Concrete Materials and Methods of Concrete Construction / Methods of Test for Concrete, 2001ASTM C 33 02ASTM C 33-02Highway Research Record #45, Highway Research Board, 1964Virginia Highway Research Council Potentially Reactive Carbonate Rocks Progress Report #7b The Effects of Textural and External Restraints on the Expansion of Reactive Carbonate Aggregates, M. H. Hilton, 1968U S B f R l ti P t h f th Chi k Li t W Y H ll d 1936U.S. Bureau of Reclamation, Petrography of the Chickamauga Limestone, W. Y. Holland, 1936Principles of Engineering Geology and Geotechnics, D. P. Krynine, W. R. Judd, 1957Federal Highway Administration FHWA-RD-03-047, Guidelines for the Use of Lithium to Mitigate or Prevent Alkali-Silica Reaction, 2003Federal Highway Administration FHWA HRT-04-150 Petrographic Methods of Examining hardened C t A P t hi M l H N W lk D S L P E St t 200Concrete: A Petrographic Manual, H. N. Walker, D. S. Lane, P. E. Stutzman, 200Use of the Accelerated Mortar Bar Test for Evaluating the Efficacy of Mineral Admixtures for Controlling Expansion due to Alkali-Silica Reaction, M. D. A. Thomas, F. A. Innis, 1999ACI Materials Journal 95-M71, Effect of Slag on Expansion Due to Alkali-Aggregate Reaction in Concrete, M. D. A. Thomas, F. A. Innis, 1998