[PDF] ALKALI-SILICA REACTIVITY: AN OVERVIEW OF RESEARCH

View - Download ALKALI-SILICA REACTIVITY: AN OVERVIEW OF RESEARCH

Previous PDF

Next PDF

SHRP-C-342

Alka l i-Si l icaReactivity:AnOverviewofResearch

RichardHelmuth

ConstructionTechnologyLaboratories,Inc.

Withcontributionsby:

DavidStark

ConstructionTechnologyLaboratories,Inc.

SidneyDiamond

PurdueUniversity

MichelineMoranville-Regourd

EcoleNormaleSuperieuredeCachan

StrategicHighwayResearchProgram

Nat i onalResearchCouncil Was h ington ,DC1993

PublicationNo.SHRP-C-342

ISBN0-30cL05602-0

ContractC-202

ProductNo.2010

ProgramManager:DonM.Harriott

ProjectMaxtager:InamJawed

ProgramAIeaSecretary:CarinaHreib

Copyeditor:KatharynL.BineBrosseau

May1993

keywords: additives aggregate alkali-silicareaction cracking expansion po rtlandcementconcrete standards

StrategicHighwayResearchProgram

2101Consti!utionAvenueN.W.

Washington,DC20418

(202)334-3774 T specificallyexpressedherein.

©1993NationalAcademyofSciences

1.5M NAP 593

Acknowledgments

o T C o c o ntract o an Fun d o w o imp o M o ran v ille-Reg o ur d kn o Kn o p r Diam o n d byStarkandHelmuth. ..o 111

Contents

Acknowl

e dgm e

Execut

i V 5. 1 vi

ListofFigures

CausedbyReactionof15%FlyAshBlendswith

CausedbyReactionofFlyAshinBlendswith

0.67%SodiumOxideequivalentPortlandCement

ParticleSurfaceCausedbyPasteShrinkage,or

vii inTriaxiallyConfinedConcretesStoredat ..o V U l

ListofTables

T

Opal)andAdditionsofSodiumChlorideand

ix

Abstract

containingsaltscomplicatestestresults. inhibitionofreactivitybychemicalagents.

ExecutiveSummary

focusoflaboratoryandfieldinvestigations. identified;thesearepresentedinPartII. work.Majorfindingsareasfollows. hydrateintheASRgel. mol usedwithhigh-alkalicements. Na20

SiO2ratioofabout0.19.

3 swellingofgeloccursprogressively. occurs,orbygelflowandcreep. pressures. incomplete. 4 needforacceleratedtestprocedures. concentratedlocallybydrying. 5

SilicaReactivity

1Introduction

reduc ti Howe v er 7 sites,areimportantvariables. 8 makinginourcurrentresearchforSHRP. 9

2ReactionChemistry

2.1ReactionwithAlkaliHydroxides

Reac t theamountofundissolvedsilica(10). 11

Thereactioncanberepresentedas:

H2xSiO2

x+2xNaOH-->Na2xSiO2._x+2xH20(2.1.1) slightlyswelltherigidsilicastructure. simplifiedformas: bepolymeric. 176
12 25
c o ncentrati o Alkal s o lu t i o 13 mol alkaliesbythecementgel. mainlybyalkaliconcentration: [Ca 2 +]'[OH-]2=K_,-[Ca2+]'[Na+]::(2.2.2) 14 mol Na z

O-CaO-SiO

z w 15 Pozz o hydroxylions; 16 0.7

15%FlyAsh0.6,-

_0.5 _0.3-0.2 -r0.1 C o ncentration.

IIIIII0102030

PercentFlyAshReacted

0.7 '(pc)20%and40%FlyAshJ----0.6 =o_"0.5O.4 80.3A
g,0.2-

RBT0.1Concentration._%_III_II0102030

PercentFlyAshReacted

B C 17 differentcompositions. (80 structuresinpractice(31,32). mol _8 I Rea c

ASRGelsfromConcreteStructuresH20

Greywacke

/72161.89--(34)Homfels (5Structures)Limestone Ex ud edSurfaceGelsAtomicC/S

Asabove,Washed"61.931.9....0.55(31)

GelsinCracksandAirVoids

A sabove,Washed"60.837.6....0.66(31)

Asabove,Washed"52.447.6....0.97(31)

ASRCrystalsfromConcreteStructures

Rosette-Like(a)Not68.618.2--13.2--(30)

identified

Rosette-Like(a)"71.117.1--I1.8--(30)

%A1203 Rose t te-Lik e(a)"76.99.49.14.6(30)

Needlerod-Like"63.78.913.114.3--(30)

Needlerod-Like"60.31.18.418.2--(30)

Blade-Like"71.211.6--17.2--(30)

m ortarprism)Metasediment

Asabove,Washed*71.026.51.70.80.40(31)

Rosette-Like(a)"63.520.7--15.80.35(31)

(concretepats) A sabove,Washed"67.021.7--11.30.35(31) (a)Possiblylamellar 19 becauseoftoorapidtransit. 20 50
o _CaO%+Na20%K20%=100-SIO2%O '40CaO%=103-1.24SIO2%+ OoJ z30+ O20

O10OCaO%J5060708090100

SIO2%byWeight

1 0 0 o _(C-N+K-S)%.,s'*SS'* _"80(N+K)/S=0.165 JI z"Z"60(N+K-S)%o(N+K)/S=0.20 o _ '_ '40-+ Z! 0 20- _' s sIII

405060708O90

SIO2%byWeight

21
A changesaretoosmalltobeimportant. swellingASRgels.

3.1ChemicalShrinkage

Measuredchangesareevenlarger.

23
solutioniscalculatedtobe0.242mL/g.

3.2SwellingofUndissolvedSilica

d i (50° C 24

3.3ShrinkageandSwellingofGels

M 2 0 SiO

2RelativeWaterContentSolidsNa20orK20

Na0.2?*--74264.3

68"F(20°C)97--57447.3

(41)93--49518.585--406010.0

Na0.339723070307.5

77°F(25°C)?*16062389.4

(42)9069415915.78648326816.9

6033257518.7

K0.489727673278.6

77°F(25°C)?*190663410.9

(42)9075435718.28654356520.8

6036267423.7

*aspreparedIIII

0.2in.(0.5mm).

25

Vg=0.46+0.98wg(3.3.1)

valuesoftheinterceptsareasfollows: Des o rp tior ,Adsorption*Average_ A valuesforopal.

3.4OsmoticSwellingPressures

Pi=-(RT/u)In(Pi/Po)(3.4.1)

26
%Na20%NaOHNaOHRH(44)PP bywt.bywt.mol/L%(MPa)(psi)

0.00.00.0100.00.00

2.112.730.7097.73.1450

4.295.541.50956.91000

7.629.832.719014.22067

10.3213.323.88522.03188

12.4716.104.78030.24378

14.4118.605.57538.95644

1psi=6.895kPa

permittingadditionaldilution. mL con t 28

3.5OsmoticCellTests

mate ri stu d o sm o liqui 29
rea cquotesdbs_dbs46.pdfusesText_46

[PDF] Le Chatelier#exercices 1

[PDF] Le Chatelier#exercices2

[PDF] Le Chatelier#question

[PDF] le chatelier's principle example problems

[PDF] le chatelier's principle khan academy

[PDF] le chatelier's principle temperature

[PDF] le chatelier's principle volume

[PDF] le chatelier's principle worksheet

[PDF] Le chauffage à l'epoque Moderne

[PDF] le chauffage electrique

[PDF] Le chauffe électrique et le compresseur

[PDF] le chef d'oeuvre inconnu analyse des personnages

[PDF] le chef d'oeuvre inconnu mouvement littéraire

[PDF] le chef d'oeuvre inconnu questionnaire de lecture

[PDF] le chef d'oeuvre inconnu themes