Specifying Manufacture Sands for Concrete Applications

Report
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
• 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 IN
CONSTRUCTION MATERIALS
3
OPTIMUM USE OF SANDS
NATURAL 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 CHARACTERISTICS
TO 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.
7
IMPORTANT CHARACTERISTICS
TO ALL CONCRETE
Properties
AS 2578.1 – 1998
AS 2578.1 – 2012?
Durability
Sodium sulfate weight loss
12% 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.
Impurities
Tested negative to the presence of
sugar. Reported soluble salts &
others
No change.
Performance
criteria
-
Draft AS1141.60.1 AMBT & 60.2 CPT
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 CHARACTERISTICS
TO 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
MACROTEXTURE
IN SKID & ABRASION RESISTANCE
MACROTEXTURE
Weller and Maynard (1970)
• Tyned grooves provide drainage to
prevent hydroplanning
• Mechanical resistance to skiding
S Bulahdelah
Shackel et al.,(1994)
• Dependent on mix & curing
ICAR Barborak and Rached, (2010)
• Effect of textures & travel speed on
skid (friction)
Mittagong Bypass
10
Effect of textures on skid
ICAR Barborak and Rached, (2010)
Tined+Carpet
Broom Finish
Carpet Drag
Smooth
Grass
11
EFFECT OF SAND ON MICROTEXTURE
SKID & ABRASION RESISTANCE
MAN SAND TESTING
Historical perspective
Mineralogical
compositions
Source Rocks
▼
Coarse
Aggregates
▼
Man Sands
Micro-Deval
Apsortion
Silica Content
Micro-Deval - abrasion
Na2SO4 Soundness - stability
Absorption – stability
MBV x Passing 75-micron - durability
Lab-prepared
Concrete
Specimens
Natural Sand
FIELD ASSESSMENTS
SCRIMS and other
by Road Authority
LAB CONCRETE TESTING
Skid before & after wear
Wear loss (AS 1141.41)
Abrasion loss (AS 4456.9)
Performance
Criteria
Field-retrieved
Concrete
specimens
Figure 1
12
MANUFACTURING & TESTING OF CONCRETE
3 Natural sands and
9 Manufactured sands at 50% & 80% of total fine
Random
Designation
Description by
Supplier
Petrographic Description
Approx free
(1)
silica ,%
NS Control
Emu Coarse
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
69
13
Sand durability tests
• Micro-Deval
% abrasion in water
• Sodium Soundness
stability due to expansive
salt crystallization
• Absorption
Porosity
• Free Silica Content
Petrography
Chemical
14
RMS Collaboration - Tarcutta Range test site
15
Truck Rest
Test site is on the S/B,
opposite the entrance to the
Truck Bay
To Wagga Wagga
2820
Skid of various surfaces from
lab-prepared & field sampled
skid after wear of workmanship-independent surfaces
Tyned surface
Field
sample
Sawn surface
Lab
sample
Off-form surface
16
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)
2-hr with coarse abrasion [Balck silicon carbide No. 320 @ 2g/min]
2-hr with fine abrasion [Optical emery No. 600 @ 2g/min]
18
Abrasion index (AS 4456.9)
4 circular faces subjected to 600 steel balls
60 rev/min x 1 hr = 3600 cycles
19
Skid (friction) after abrasion by PAFV
of off-form concrete
Rosebrook
S51 LS/Dolomite
T68 Quartzite
G80 Meta greyw acke
75
70
Off-form
65
Intrinsic Skid
Skid
60
55
50
45
40
0
2
4
6
8
10
PAFV, hour
20
Skid (friction) after abrasion by PAFV
of saw-cut concrete
Rosebrook
S51 LS/Dolomite
T68 Quartzite
G80 Meta greyw acke
75
70
Saw -cut
65
Skid
60
55
50
45
40
0
2
4
6
PAFV, hour
8
10
“Characteristic skid resistance ”
Common skid resistance of off-form &
saw-cut surfaces after 4-5 hrs of polishing
80
75
Skid Resistance
70
65
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
Characteristic skid
60
55
50
45
40
0
1
2
3
4
5
6
7
8
Abrasion, hour
22
Relating skid resistance
of various surfaces
Lab-prepared concrete
Field-sampled concrete
Intrinsic Skid
SCRIM
Characteristic Skid Resistance
Sand
properties
Off-form
8-hours
polishing
Off-form
4-hours
polishing
Saw-cut
4-hour
polishing
Saw-cut
4-hour
polishing
Tyned
23
Skid after wear of concrete
with various sands
SCRIM results: Mittagong 68, 71
Tarcutta 74, 68
80
Top wearing surface
70
Off-form surface, 80% man sand
61.5
Saw-cut surface, 80% man sand
Skid after 4-hr polishing
60
55
50.5
50
49
51.5
51
67
64
52
49.5
55.5
53.5
57.5
50.5
46
45
40
30
20
10
0
Emu
MS1
MS2
MS3
MS4
MS5
MS6
MS7
MS8
MS9
NS10
NS11
Mttg
Tarc
24
Intrinsic Skid and micro-Deval
or free silica content of Sands
70
65
Skid of off-form surface after 8 hr polishing
Skid of off-form surface after 8 hr polishing
70
2
R = 0.4875
60
55
50
45
65
60
55
83% Corr
50
2
R = 0.6931
45
40
40
40
50
60
70
% Free Silica (chemical)
80
90
0
5
10
15
20
25
MDV of indiv sand
25
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 strength
and independent of type of sand
28-day Compressive Strength, MPa
60.0
55.0
2.5, 50.9
50.0
45.0
40.0
65% Corr R
2
= 0.4282
35.0
30.0
1.00
1.50
2.00
2.50
3.00
3.50
4.00
Off-form abrasion index
27
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 values
http://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

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