tests on portland cement.pdf

8/14/2019 Tests on Portland Cement.pdf

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Dr. Kimberly KurtisSchool of Civil Engineering

Georgia Institute of TechnologyAtlanta, Georgia

Tests on Portland Cement

Composition

~ 5CSH2CaSO42H2OCalcium sulfate dihydrate

5 - 15C4AF4CaOAl2O3Fe2O3Tetracalcium aluminoferrite

5 - 10C3A3CaOAl2O3Tricalcium aluminate

15 - 30C2S2CaO SiO2Dicalcium silicate

50 - 70C3S3CaOSiO2Tricalcium silicate

Mass

(%)

Shorthand

NotationChemical FormulaChemical Name


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CompositionThe relative quantities of each of these phases affects:

setting time

rate of strength development

overall strength

durability

color

It is important, then, to know the composition of the

cement.

Physical Properties

Fineness

Soundness

Consistency

Setting time

False set and flash set

Compressive strength

Heat of hydration

Loss on ignition

Density

Bulk density

Sulfate expansion

Tests on Portland, Blended & Hydraulic CementsTests on Portland, Blended & Hydraulic Cements

Chemical Properties

Chemical analysis

Compound composition

Chemical limits


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Alite, C3S

Belite, C2S

Width o f field = 0.31 mm


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http://www.bruker-axs.de/

Chemical AnalysisChemical Analys is

ASTM C 114 Standard Test

Methods for Chemical Analysis

of Hydraulic Cement

Manganic oxideMn2O3

Sulfide sulfur

Titanium dioxideTiO2

Phosphorus pentoxideP2O5

Zinc oxideZnO

Potassium oxideK2O

Sodium oxideNa2O

Loss on ignitionLOI

Sulfur trioxideSO3

Magnesium oxideMgO

Calcium oxideCaO

Ferric oxideFe2O3

Aluminum oxideAl2O3

Silicon dioxideSiO2

Major components

Minor components

Separate determinations

Insoluble residue

Free calcium oxide

CO2 (carbon dioxide)

Water-soluble alkali

Chloroform soluble organic

substances


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ASTM C114

Oxide %

SiO2 20.6

Al2O3 5.07

Fe2O3 2.90

CaO 63.9

MgO 1.53

K2O 0.73

Na2O 0.15SO3 2.53

LOI 1.58

Oxide Analysis

+ other trace elements

Oxide Shorthand Common Name

CaO C lime

SiO2 S silica

Al2O3 A alumina

Fe2O3 F ferric oxide

MgO M magnesia

H2O H water

K2O Kalkalis

Na2

O N

SO3 sulfateS

CO2 carbonateC

90 95%

(Only valid when A/F 0.64)

C2S = 2.87S 0.75C3S

C3A = 2.65A 1.69F

C4AF = 3.04F

Bogue Composition

Compound CompositionCompound Composition

C3S = 4.07C 7.60S 6.72A 1.43F 2.85S


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Bogue Composition: ExampleOxide Analysis

C3S = 4.07(63.9) 7.60(20.6) 6.72(5.07)

1.43(2.90) - 2.85(2.53) = 58.1

C2S = 2.87(20.6) 0.754(58.1) = 15.6

C3A = 2.65(5.07) 1.69(F 2.90) = 8.5

C4AF = 3.04(2.90) = 8.8

Calculated Phase Composition

Oxide %

SiO2 20.6

Al2O3 5.07

Fe2O3 2.90

CaO 63.9

MgO 1.53

K2O 0.73

Na2O 0.15

SO3 2.53

LOI 1.58

9%C4AF

9%C3A

16%C2S

58%C3SBogue Potential Composition:

Oxide %

SiO2 20.6

Al2O3 5.07

Fe2O3 2.90

CaO 63.9

MgO 1.53

K2O 0.73

Na2O 0.15

SO3 2.53

LOI 1.58

Typical Chemical Composition of Portland Cement

Oxide Analysis

+ other trace elements

Sodium equivalent, Na2Oe

Na2Oe = Na2O + (0.658 x K2O)

Na2Oe = 0.15 + (0.658 x 0.73)

Na2Oe = 0.63%


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Bogue CompositionThe Bogue equations are based on the following assumptions:

1) All 4 phases are pure2) All the F present occurs as C4AF, and the quantities of A =

0.64(%F) and C = 1.40 (%F) are subtracted from the

appropriate totals.

3) The remaining Al2O3 is combined as C3A and a further quantity

of C = 1.65 (% Al2O3) is subtracted fromt eh total remaining

CaO.

4) The SiO2 combines initially with CaO to form C2S giving a

provisional C2S figure. The CaO combining with SiO2 =

2.87%(SiO2) is subtracted from the total CaO figure, and the

remaining CaO is then combined with a part of the C2S =

4.07(%CaO) to form C3S.As a resul t, Bogue composi tions may be of f by as much as

10% compared to XRD-determined compositions.

BogueXRD


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Chemical LimitsChemical Limits

6.06.06.06.06.0MgO, max. %

3.02.53.03.03.0LOI, max. %

0.750.750.750.750.75Insoluble residue,

max. %

Cement Type

3.0

n/a

2.3

n/a

3.5

4.5

3.0

n/a

3.0

3.5

SO3, max. %

C3A 8%

C3A > 8%

-6.5-6.0-Fe2O3, max. %

---6.0-Al2O3, max. %

---20.0-SiO2, min. %

VIVIIIIII

ASTM C 150 Portland Cement - Chemical Requirements


Cement Type

25----C4AF + 2 C3A,

max. %

57158-C3A, max. %

-25---C2S, min. %

-35---C3S, max. %

VIVIIIIII

ASTM C 150 Portland Cement - Chemical Requirements


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Cement Type

0.600.600.600.600.60Na2Oe, max. %

---58-C33 + C3A, max. %

--5--C3A, max. %

--8--C3A, max. %

VIVIIIIII

ASTM C 150 Portland Cement Optional Chemical Requirements


5.04.03.0LOI, max. %

-0.03*-Water-soluble alkali, max. %

6.0--MgO, max. %

-2.02.0Sulfide sulfur (S), max. %

-1.01.0Insoluble residue, max. %

Cement Type

4.04.03.0Sulfur reported as SO3, max.

%

I(PM),

I(PM)-A, P,

PA,

IP, IP-A

S, SAI(SM), I(SM)-

A, IS, IS-A

ASTM C 595 Blended Cement - Chemical Requirements

*Only required when cement is specified to be nonstaining to limestone


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FinenessFineness

Fineness of cement is also important; it affects:

rate of hydration

rate of setting

rate of hardening

durability (ASR)

rate of carbonation during storage

cost

rate of gypsum addition

bleeding

However, later strength is not directly affected.

Neville, Fig. 1.5

FinenessFineness


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Approx. 95% 45 microns

Average diameter ~ 15

microns

Those retained on the No 200

sieve (75 microns) will never

hydrate completely

Those retained on the No 325

sieve (45 microns) will be

difficult to hydrate completely

FinenessFineness

Type III >> Type I, II, V > Type IV

Fineness is generally described as the specific surface of the

cement, which is the surface area expressed in m2/kg


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Lea and Nurse Air PermeabilityLea and Nurse Air Permeability

Relates flow of fluid (air)through a bed of granular

material (cement) to the specific

surface area of that granular

material

By knowing cement, a bed 10mmthick with porosity of 4.75% is

made; air is passed through at

constant velocity; pressure drop

is measured.

Sw= 14 [(3Ah1)/(KLh2)]

0.5

(1-)

Blaine Air PermeabilityBlaine Air Permeabili ty

Blaine Air Permeability

(ASTM C 204)

With the Lea Nurse method, air

passes through the bed at a constant

rate

In the Blaine test, a known volume of

air passes at a constant pressure

through the bed

The rate of flow decreases steadily

The time for flow to occur is

measured for a given apparatus and a

standard porosity of 5% (0.500).

Sw = K2t0.5


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WagnerWagner TurbidimeterTurbidimeter

Wagner Turbidimeter

(ASTM C 115)

Uses a photoelectric cell to

measure light passing through

cement particles suspended

in kerosene

Test is based on Stokes Law

that states that a sphere will

obtain a constant velocity

under the action of gravity

Allows calculation of particle-

size distribution (psd)

Blaine, in general, is 1.8X Wagner

Laser Particle Size AnalyzerLaser Particle Size Analyzer

Laser particle sizeanalyzer

Particle-size distribution

(psd)


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Cement FinenessCement Fineness

ASTM C 430

Sample washed over 45-m (# 325) sieve Used in production

Limits for pozzolans and slag (ASTM C 595)

Cement FinenessCement Fineness

Requirements for Type I, II, IV & V

(No requirements for Type III)

Minimum, m2/kg

Air Permeability Turbidimeter

ASTM C 150 &

AASHTO M 85280 160

Maximum, m2/kgAASHTO M 85 400 220

No limits for blended cement (ASTM C 595) or hydraulic cements

(ASTM C 1157) but values must be reported on mill test reports

Typical values, m2/kg 350-380 Type I

450-600 Type III


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SoundnessSoundness

Soundness - ability of hardened paste to

maintain volume after setting

Unsoundness (abnormal expansion)

caused by hard-burned CaO or MgO

22 )(OHCaOHCaO +

22 )(OHMgOHMgO +

ASTM C 151 Standard Test Method for

Autoclave Expansion of Portland Cement

Expansion for all portland,

blended & hydraulic cements 0.80%

ConsistencyConsistency

Consistency of Cement Paste

Penetration of 10 1 mm of Vicat plunger


Normal Consistency of Hydraulic Cement

Consistency of Mortar

Flow table


Flow of Hydraulic Mortar


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Setting TimeSetting Time

Initial Set

Final Set

Time from moment water is added until the paste

ceases to be fluid and plastic

Time from moment water is added for the paste to

acquire a certain degree of hardness

Setting Time: Standard TestSetting Time: Standard Test

Vicat Needle


Time of Setting of Hydraulic Cement by

Vicat Needle

Initial set occurs when needle penetrates

- after 30s - 25 mm (1 inch) into paste

Final set occurs when there is no visible

penetration


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Setting Time: Field MeasurementsSetting Time: Field Measurements

Concrete penetrometer, measures

resistance to penetration in sieved mortar

samples

Pocket penetrometers

Setting Time: Standard TestSetting Time: Standard Test

Gillmore Needles

ASTM C 266 Standard Test

Method for Time of Setting of

Hydraulic-Cement Paste by

Gillmore Needles

Setting determined as time when

paste resists indentation by

needles


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ASTM C 150 Por tland Cement

Initial Set, not less than (h:min)

Final Set, not more than (h:min)

Vicat Needle Gillmore Needles

0:45

6:15

1:00

10:00

ASTM C 595 Blended Cement



0:45

7:00

ASTM C 1157 Hydrau lic Cement



0:45

7:00


0 100 200 300 400

Type V

Type IV

Type III

Type II

Type I

Time of Set (Minutes) - Vicat Method

Initial

Final


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False Set and Flash SetFalse Set and Flash Set

False Set Loss of plasticity shortly after mixing little heat

Due to hemihydrate (plaster) in cement

hydrating to gypsum

Workability restored by additional mixing

Early Stiffening Early Stiffening

False Set and Flash SetFalse Set and Flash Set

False Set Loss of plasticity shortly after mixing little heat

Due to hemihydrate (Plaster) in cement

hydrating to Gypsum

Workability restored by additional mixing

Flash Set Rapid & early loss of workability significant heat

Due to rapid reaction of aluminates when

insufficient sulfate present

Workability cannot be restored

Early Stiffening Early Stiffening


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Compressive StrengthCompressive Strength

ASTM C 109 Standard Test Method

for Compressive Strength of Hydraulic

Cement Mortars.

50-mm (2-inch) mortar cubes

Sand:Cement = 2.75:1

Water/Cement = 0.485 for portland

cement (0.460 for air-entraining

portland cement)

Sufficient water for flow 110 5 for

blended (ASTM C 595) and

hydraulic (ASTM C 1157) cements


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ASTM C 150 Standard Specification for Portland Cement

Cement Type

21.0

(3050)

17.0

(2470)

---28 days

15.0

(2180)

7.0

(1020)

-17.0

(2470)

19.0

(2760)

7 days

8.0

(1160)

-24.0

(3480)

10.0

(1450)

12.0

(1740)

3 days

--12.0

(1740)

--1 day

VIVIIIIII

Age

Minimum Strength Requirements, MPa (psi)


Lower strengths permitted for air-entraining cements (Types IA, IIA & IIIA)

and when heat of hydration option is specified for Type II cement

ASTM C 595 Standard Specification for Blended Hydraulic Cements

Cement Type

21.0

(3140)

11.0

(1600)

25.0

(3620)

25.0

(362)

28 days

11.0

(1600)

5.0

(720)

18.0

(2610)

20.0

(2900)

7 days

--11.0

(1600)

13.0

(1890)

3 days

PSIS(MS),

IP(MS)

I(SM), IS,

I(PM), IP

Age

Minimum Strength Requirements, MPa (psi)


Lower strengths permitted for air-entraining cements (with suffix A)


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ASTM C 1157 Standard Specification for Hydraulic Cement

Cement Type

17-17---28 days

5101017-177 days

-551017103 days

----10-1 day

LHMHHSMSHEGU

Age

Minimum Strength Requirements (MPa)


ASTM C 1157 Standard Specification for Hydraulic Cement

-60

(8700)

40

(5800)

30

(4350)

20

(2900)

15

(2175)

Maximum Strength,

MPa (psi)

45

(6525)

35

(5075)

25

(3625)

17

(2465)

10

(1450)

5

(725)

Minimum Strength,

MPa (psi)

45352517105Strength Range

Minimum Strength Requirements (MPa)



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Heat of HydrationHeat of Hydration

Heat evolution in portland cement tested by conduction calorimetry

Heat of Solution Test


Heat of Hydration of Portland Cement

Conduction Calorimetry



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Moderate Heat

of Hydration

Low Heat of

Hydration

ASTM C 150

Portland Cement

Type II (Option)

290 kJ/kg at 7 days

Type IV

250 kJ/kg at 7 days

290 kJ/kg at 28 days


Moderate Heat

of Hydration

Low Heat of

Hydration

ASTM C 150

Portland Cement

Type II (Option)

290 kJ/kg at 7 days

Type IV

250 kJ/kg at 7 days


ASTM C 595

Blended Cement

Suffix -MH Suffix -LH

250 kJ/kg at 7 days


290 kJ/kg at 7 days



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Moderate Heat

of Hydration

Low Heat of

Hydration

ASTM C 150

Portland Cement

Type II (Option)

290 kJ/kg at 7 days

Type IV

250 kJ/kg at 7 days


ASTM C 595

Blended Cement

Suffix -MH Suffix -LH

250 kJ/kg at 7 days


290 kJ/kg at 7 days


ASTM C 1157

Hydraulic Cement

Type MH Type LH

250 kJ/kg at 7 days


290 kJ/kg at 7 days

Loss on IgnitionLoss on Ignition

ASTM C 114 Standard Test Methods

for Chemical Analysis of Hydraulic

Cement

Loss on ignition LOI

Sample ignited at 900 to 1000C

(1650 to 1830F)

High LOI indicates prehydration

and/or carbonation

Improper or prolonged storage

(transportation)

ASTM C 150 Portland Cement LOI 3.0% (2.5% for Type IV)

ASTM C 595 Blended Cement LOI 3.0 5.0%

ASTM C 1157 Hydraulic Cement No limit must be reported


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DensityDensity

Le Chatelier flask - ASTM C 188 Standard

Test Method for Density of Hydraulic Cement

HeliumHelium pycnometerpycnometer

Range= 3100 to 3250 kg/m3

Average = 3150 kg/m3 (196 lb/ft3)

Not indicator of quality

Used for mixture proportioning

calculations

Relative density (specific gravity) = 3.15

Bulk DensityBulk Density

Bulk density of cement varies

between

830 kg/m3 (52 lb/ft3)

and

1650 kg/m3 (103 lb/ft3).


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ASTM C 452 Standard Test Method for Potential Expansion ofPortland-Cement Mortars Exposed to Sulfate

Sulfate ExpansionSulfate Expansion

Gypsum added to cement to yield 7.0% SO3 (by mass of

cement + gypsum)

Mortar bars stored in water

Length change monitored periodically

Only applicable to portland cements

ASTM C 150 Portland Cement

Optional requirement for

Type V Sulfate-Resisting

Portland Cement

Expansion 0.040%

at 14 days

Limits for C3A, C4AF

+ 2C3A, SiO2 & Fe2O3not required

tests on portland cement.pdf

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