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SPECIFYING MANUFACTURED SANDS FOR CONCRETE APPLICATIONS. Vute Sirivivatnanon Associate Professor of Construction Materials University of Western Sydney Ion Dumitru Chairman – Manufactured Sands Research Steering Committee Cement Concrete & Aggregate Australia. CONTENTS. - PowerPoint PPT Presentation
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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
6
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.
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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
12
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)
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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
19
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
20
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
22
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
25
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
28
-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)
28
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.
29
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)
30