SPECIFYING MANUFACTURED SANDS FOR CONCRETE

APPLICATIONS

Vute SirivivatnanonAssociate Professor of Construction Materials

University of Western Sydney

Ion DumitruChairman – Manufactured Sands Research Steering Committee

Cement Concrete & Aggregate Australia

CONTENTS

• Sustainability measures in construction materials

• Optimum use of natural & manufactured sands

• Important sand characteristics to all concrete

• Important sand characteristics to concrete pavement

• CCAA/RMS collaborative study

• Performance-based specifications

2

SUSTAINABILITY MEASURES INCONSTRUCTION MATERIALS

3

OPTIMUM USE OF SANDSNATURAL SAND

Recovered from geologically recent deposits such as

• Morton Bay, • Kurnell dunes, and• Nepean River flood plain

Excellent fine aggregate from geological processes of shaping and sorting resulting in

• Rounded to sub-rounded and smooth surface

• Removal of weaker minerals

4

OPTIMUM USE OF SANDS MANUFACTURED SAND

Suitable source rock purpose-made throu• Crushing, • Screening (sizing & blending), and• possible washing to control microfines

≠ crusher dusts as blend component in road bases, fills, fines, and stabilized crusher fill.

5

IMPORTANT CHARACTERISTICS TO ALL CONCRETE

GRADING, SHAPE & TEXTURE, FREE OF DELETERIOUS FINES, DURABLE & NON REACTIVE, GOOD SKID RESISTANCE

The challenge is to apply engineering knowledge to the best & economical use of manufactured sands through appropriate specifications

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IMPORTANT CHARACTERISTICSTO ALL CONCRETE

Properties AS 2578.1 – 1998 AS 2578.1 – 2012?

Density 2.1-3.3 t/m3 at ssd. No change.

Particle size distribution

Grading with limits for 7 sieve sizes. Each size max. deviation limits.

“Submitted” grading & general limits at 3 sieve sizes. Deviation limit at 75µm reduced from ±5% to ±3%.

Particle shape None. Test procedures & limits to be specified if required.

Deleterious fines % passing 75µm ≤ 5% uncrushed fine, ≤ 20% crushed fine.% passing 2µm ≤ 1%.

MBV x % passing 75µm ≤ 150 for individual sand, and≤ 100 for combined sand.Sand equivalent ≥ 60 for individual & combined sand.

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IMPORTANT CHARACTERISTICSTO ALL CONCRETE

Properties AS 2578.1 – 1998 AS 2578.1 – 2012?

Durability Sodium sulfate weight loss12% for exposure class B2 & C,15% for exposure class A2 & B1.

Sodium sulfate weight loss limit reduced to 6% for all exposure classes.

Alkali-reactive materials

Supply of documentation to allow assessment of potential reactivity.

No change. Draft AS1141.60.1 AMBT & 60.2 CPT

Impurities Tested negative to the presence of sugar. Reported soluble salts & others

No change.

Performance criteria

- Criteria for total rather than each fine aggregate.Also recommended use of any manufactured sand in concrete to be confirmed with mix design trials.

8

IMPORTANT CHARACTERISTICSTO CONCRETE PAVEMENT

Concrete pavement must be fit for purpose• Resistance to wear (abrasion of texture)• Good skid resistance in wet and dry condition

Skid resistance depends on the complementary functions of macro- & microtexture

• Microtexture: λ< 0.5mm• Macrotexture: 0.5<λ< 50mm

9

MACROTEXTUREIN SKID & ABRASION RESISTANCE

MACROTEXTUREWeller and Maynard (1970)• Tyned grooves provide drainage to

prevent hydroplanning• Mechanical resistance to skiding

Shackel et al.,(1994)• Dependent on mix & curing

ICAR Barborak and Rached, (2010)• Effect of textures & travel speed on

skid (friction)

S Bulahdelah

Mittagong Bypass

10

Effect of textures on skidICAR Barborak and Rached, (2010)

Smooth

Broom Finish

Tined+Carpet

Grass

Carpet Drag

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EFFECT OF SAND ON MICROTEXTURESKID & ABRASION RESISTANCE

MAN SAND TESTING

Micro-Deval - abrasionNa2SO4 Soundness - stabilityAbsorption – stabilityMBV x Passing 75-micron - durabilitySource Rocks

▼Coarse

Aggregates▼

Man SandsMicro-DevalApsortion

Historical perspective

Natural Sand

Mineralogicalcompositions

Silica Content

LAB CONCRETE TESTING

Skid before & after wearWear loss (AS 1141.41)

Abrasion loss (AS 4456.9)

Lab-preparedConcrete

Specimens

FIELD ASSESSMENTS

SCRIMS and otherby Road Authority

Field-retrievedConcrete

specimens

Performance Criteria

Figure 1

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MANUFACTURING & TESTING OF CONCRETE3 Natural sands and9 Manufactured sands at 50% & 80% of total fine

Random Description by Supplier

Petrographic Description Approx free silica (1) ,%Designation

NS Control Emu Coarse   69

MS1 Meta-argillite Meta-argillite 22

MS2 Olivine Basalt Olivine Basalt 2

MS3 Micro-granite Micro-diorite 6

MS4 Basalt (Latite) Latite 45

MS5 Ignimbrite Rhyolitic tuff 36

MS6 Adamellite Granite 48

MS7 Ignimbrite (Rhyodacite) Rhyolitic tuff 31

MS8 Meta-Greywacke Meta - Greywacke 27

MS9 Rhyodacite Rhyolitic tuff 29

NS10 ex Wagga Wagga Metasiltstone, quartzite 80

NS11 ex Billabong Quartzofeldspathic and lithic 64 13

Sand durability tests

• Micro-Deval% abrasion in water

• Sodium Soundnessstability due to expansive

salt crystallization

• AbsorptionPorosity

• Free Silica ContentPetrographyChemical

14

To Wagga WaggaTo Wagga Wagga

Truck RestTruck Rest

Test site is on the S/B, opposite the entrance to the

Truck Bay

2820

RMS Collaboration - Tarcutta Range test site 15

Skid of various surfaces from

lab-prepared & field sampledskid after wear of workmanship-independent surfaces

16

Field sample

Lab sample

Off-form surface

Tyned surface

Sawn surface

Pendulum friction test (AS 1141.42)Friction Value FV

17

PAFV abrasion resistance (AS 1141.41)33-35 revs/min (8,000&16,000 cycles after 4 & 8 hours)

18

2-hr with coarse abrasion [Balck silicon carbide No. 320 @ 2g/min]

2-hr with fine abrasion [Optical emery No. 600 @ 2g/min]

Abrasion index (AS 4456.9)4 circular faces subjected to 600 steel balls

60 rev/min x 1 hr = 3600 cycles

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Off-form

40

45

50

55

60

65

70

75

0 2 4 6 8 10

PAFV, hour

Ski

d

RosebrookS51 LS/DolomiteT68 QuartziteG80 Meta greyw acke

Skid (friction) after abrasion by PAFVof off-form concrete

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Intrinsic Skid

Skid (friction) after abrasion by PAFVof saw-cut concrete

Saw-cut

40

45

50

55

60

65

70

75

0 2 4 6 8 10

PAFV, hour

Ski

d

RosebrookS51 LS/DolomiteT68 QuartziteG80 Meta greyw acke

“Characteristic skid resistance ”Common skid resistance of off-form &

saw-cut surfaces after 4-5 hrs of polishing

40

45

50

55

60

65

70

75

80

0 1 2 3 4 5 6 7 8

Abrasion, hour

Skid

Resis

tan

ce

Rosebrook Off S51 LS/Dolomite Off

T68 Quartzite Off G80 Meta grey Off

Rosebrook Saw S51 LS/Dolomite Saw

T68 Quartzite Saw G80 Meta grey Saw

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Characteristic skid

Relating skid resistanceof various surfaces

Saw-cut4-hour

polishing

TynedOff-form4-hours

polishing

Off-form8-hours

polishing

Sandproperties

Field-sampled concrete

Characteristic Skid Resistance

Saw-cut4-hour

polishing

Intrinsic Skid

Lab-prepared concrete

SCRIM

23

Skid after wear of concrete with various sands

24

67

57.555

45

50.5 4951.5 51 49.5

64

52 53.5

46

55.5

50.5

61.5

0

10

20

30

40

50

60

70

80

Emu MS1 MS2 MS3 MS4 MS5 MS6 MS7 MS8 MS9 NS10 NS11 Mttg Tarc

Ski

d a

fter

4-h

r p

olis

hin

g

Top wearing surface

Off-form surface, 80% man sand

Saw-cut surface, 80% man sand

SCRIM results: Mittagong 68, 71

Tarcutta 74, 68

Intrinsic Skid and micro-Deval or free silica content of Sands

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R2 = 0.4875

40

45

50

55

60

65

70

40 50 60 70 80 90

% Free Silica (chemical)

Skid

of

off

-fo

rm s

urf

ace a

fter

8 h

r p

oli

sh

ing

R2 = 0.6931

40

45

50

55

60

65

70

0 5 10 15 20 25

MDV of indiv sand

Skid

of

off

-fo

rm s

urf

ace a

fter

8 h

r p

oli

sh

ing

83% Corr

Fowler and Rached, ‘Evaluation of the Polish Resistance of Fine Aggregates in PCC Pavements’, ( to be published in TRR)

26

Abrasion is largely a function of strengthand independent of type of sand

2.5, 50.9

R2 = 0.4282

30.0

35.0

40.0

45.0

50.0

55.0

60.0

1.00 1.50 2.00 2.50 3.00 3.50 4.00

Off-form abrasion index

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-da

y C

om

pre

ss

ive

Str

en

gth

, MP

a

27

65% Corr

Possible performance-based specifications for concrete pavement

NATURAL & MANUFACTURED SANDS• Micro-deval ≤ 15% for skid after wear

or

CONCRETE PAVEMENT (LAB)• Characteristic skid > 50 for off-form surface

• A nominated concrete strength for abrasion resistance (independent of sand used)

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CONCLUSIONS

CCAA research has lead to

• A better understanding of how to specify fit-for-purpose manufactured sands for all concrete applications. Specifications are introduced into AS 2758.1 (2012)

• Critical property of sands to concrete pavements is durability (Micro-Deval) for skid after wear & concrete strength for abrasion resistance

• Important properties to concrete producer are shape, surface texture & consistent grading.

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CCAA PUBLICATIONS ON MANUFACTURED SAND

Manufactured Sand – National test methods and specification valueshttp://www.concrete.net.au/publications/pdf/ManSand.pdf

Guide to the Specification and Use of Manufactured Sand in Concrete http://www.concrete.net.au/publications/pdf/GuideManSand.pdf

Manufactured Sand - Abrasion resistance and effect of manufactured sand on concrete mortar

http://www.concrete.net.au/publications/pdf/ManuSandReport2.pdf

Effect of manufactured sands on surface properties of concrete pavement

(to be available on CCAA website shortly)

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