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SPECIFYING MANUFACTURED SANDS FOR CONCRETE APPLICATIONS Vute Sirivivatnanon Associate Professor of Construction Materials University of Western Sydney.

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Presentation on theme: "SPECIFYING MANUFACTURED SANDS FOR CONCRETE APPLICATIONS Vute Sirivivatnanon Associate Professor of Construction Materials University of Western Sydney."— Presentation transcript:

1 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

2 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

3 SUSTAINABILITY MEASURES IN CONSTRUCTION MATERIALS 3

4 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

5 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

6 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

7 IMPORTANT CHARACTERISTICS TO ALL CONCRETE 7

8 8

9 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

10 MACROTEXTURE IN SKID & ABRASION RESISTANCE MACROTEXTURE Weller 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

11 Effect of textures on skid ICAR Barborak and Rached, (2010) Smooth Broom Finish Tined+Carpet Grass Carpet Drag 11

12 EFFECT OF SAND ON MICROTEXTURE SKID & ABRASION RESISTANCE MAN SAND TESTING Micro-Deval - abrasion Na 2 SO 4 Soundness - stability Absorption – stability MBV x Passing 75-micron - durability Source Rocks ▼ Coarse Aggregates ▼ Man Sands Micro-Deval Apsortion Historical perspective Natural Sand Mineralogical compositions Silica Content LAB CONCRETE TESTING Skid before & after wear Wear loss (AS ) Abrasion loss (AS ) Lab-prepared Concrete Specimens FIELD ASSESSMENTS SCRIMS and other by Road Authority Field-retrieved Concrete specimens Performance Criteria Figure 1 12

13 MANUFACTURING & TESTING OF CONCRETE 3 Natural sands and 9 Manufactured sands at 50% & 80% of total fine 13

14 Sand durability tests Micro-Deval % abrasion in water Sodium Soundness stability due to expansive salt crystallization Absorption Porosity Free Silica Content Petrography Chemical 14

15 To Wagga Wagga Truck Rest Test site is on the S/B, opposite the entrance to the Truck Bay 2820 RMS Collaboration - Tarcutta Range test site 15

16 Skid of various surfaces from lab-prepared & field sampled skid after wear of workmanship-independent surfaces 16 Field sample Lab sample Off-form surface Tyned surface Sawn surface

17 Pendulum friction test (AS ) Friction Value FV 17

18 PAFV abrasion resistance (AS ) revs/min (8,000&16,000 cycles after 4 & 8 hours) 18 2-hr with coarse abrasion [Balck silicon carbide No. 2g/min] 2-hr with fine abrasion [Optical emery No. 2g/min]

19 Abrasion index (AS ) 4 circular faces subjected to 600 steel balls 60 rev/min x 1 hr = 3600 cycles 19

20 Skid (friction) after abrasion by PAFV of off-form concrete 20 Intrinsic Skid

21 Skid (friction) after abrasion by PAFV of saw-cut concrete

22 “Characteristic skid resistance ” Common skid resistance of off-form & saw-cut surfaces after 4-5 hrs of polishing 22 Characteristic skid

23 Relating skid resistance of various surfaces Saw-cut 4-hour polishing Tyned Off-form 4-hours polishing Off-form 8-hours polishing Sand properties Sand properties Field-sampled concrete Characteristic Skid Resistance Saw-cut 4-hour polishing Intrinsic Skid Lab-prepared concrete SCRIM 23

24 Skid after wear of concrete with various sands 24 SCRIM results: Mittagong 68, 71 Tarcutta 74, 68

25 Intrinsic Skid and micro-Deval or free silica content of Sands 25 83% Corr

26 Fowler and Rached, ‘Evaluation of the Polish Resistance of Fine Aggregates in PCC Pavements’, ( to be published in TRR) 26

27 Abrasion is largely a function of strength and independent of type of sand 27 65% Corr

28 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

29 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 (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

30 CCAA PUBLICATIONS ON MANUFACTURED SAND Manufactured Sand – National test methods and specification values Guide to the Specification and Use of Manufactured Sand in Concrete Manufactured Sand - Abrasion resistance and effect of manufactured sand on concrete mortar Effect of manufactured sands on surface properties of concrete pavement (to be available on CCAA website shortly) 30


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