1. DEVELOPMENT OF SKID RESISTANT HOT ASPHALT MIXTURES BY BLENDING AGGREGATES FROM DIFFERENT SOURCES
AMNON RAVINA- Geokom Ltd SHIMON NESICHI – Israel National Roads Company
MAY 2011

2. Presentation Topics Summary & Conclusions
Background- Shortage of basalt aggregates in Israel's Paving Industry
R&D PROJECT :
Literature survey
Laboratory tests
Paving of a 4km experimental project
Performance monitoring
Implementation in INRC paving projects
Summary & Conclusions

3. Israel’s HMA Paving industry at a Glance : About 25 HMA plants
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (1)
Israel’s HMA Paving industry
at a Glance :
About 25 HMA plants
Annual HMA production –
5-6 million tons (about 1 ton per capita)
Million tons of surface mixtures (Annually) 3

4. Basalt Shortage Problem (1):
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (2)
Basalt Shortage Problem (1):
Only 2 types of aggregates available nationally: Dolomite and Basalt
Best Polishing Resistant aggregate – basalt (PSV= )
Most Availablable Aggregate Dolomite / Limestone (PSV =30-40) 4

5. Basalt Shortage Problem (2):
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (3)
Basalt Shortage Problem (2):
Annual demand of Basalt Aggregate tons (only 3 quarries)
Basalt is the dominant coarse aggregate type used in surface mixtures
Growing Demand due to
implementation of
SMA resurfacing policy 5

6. DGA (left) Vs. SMA (right)– Hw no. 2- 2006
DOLOMITE- DGA
BASALT- SMA
DGA (left) Vs. SMA (right)– Hw no

7. Basalt Shortage Problem (3):
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (3)
Basalt Shortage Problem (3):
Effect of shortage problems :
Delays in projects
Quality problems
Price rise 7

8. Basalt Shortage Problem (4):
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (3)
Basalt Shortage Problem (4):
Basalt Price Rise
(NIS)
DOLOMITE 8

9. Basalt Shortage Problem – Possible Solutions (5):
Background- Shortage of basalt aggregates in Israel's HMA Paving Industry (3)
Basalt Shortage Problem – Possible Solutions (5):
VTOL
Controlled Replacement of Some of the Basalt COARSE Aggregate by Dolomite (i.e.blending) WITHOUT SACRIFICING SKID RESISTANCE 9

10. SMA GRADATION CURVE
PERCENT PASSING (%)
SIEVE

11. Paving of a 4km experimental project (test sections)
DEVELOPMENT OF SKID RESISTANT HOT ASPHALT MIXTURES BY BLENDING AGGREGATES FROM DIFFERENT SOURCES
R&D PROJECT :
Literature survey
Laboratory tests
Paving of a 4km experimental project (test sections)
Performance monitoring of test sections
Implementation in INRC’s paving projects 12

12. R&D PROJECT- LITERATURE SURVEY (1)
We didn’t invent the wheel !
Two examples of applying the “blending of
aggregates” concept:
Liang - Blending proportions of high skid and low
skid aggregate- OHIO 2002
Dumitru , Vasile , Sidney - Safer roads for Tasmania
Gunn’s Hill project – skid resistance field
assessment- 2007 13

13. R&D PROJECT- LITERATURE SURVEY (2)
Blending up to 50% is possible without
sacrificing Polishing Resistance!
Start with lab tests (e.g. PSV) of varying
blends – to determine combinations
Don’t release your specs requirements
Continue with a monitoring plan of AC-mix
plant production, field test section
construction and field service performance
Approve for routine use (if successful…) 14

14. R&D PROJECT- LAB TESTS (1)
Feasibility study
Test Effect of various
combinations of basalt /dolomite
on PSV
Compare the results to the specs 15

15. R&D PROJECT- LAB TESTS FEASIBILITY STUDY (2)
2 Dolomite quarries
1 Basalt quarry
Specs limit- 48 16

16. R&D PROJECT- LAB TESTS FULL PROJECT DATA (3)
6 Dolomite quarries
1 Basalt quarry
Specs limit- 48 17

17. R&D PROJECT- LAB TESTS – CONCLUSIONS (4)
Successful Blending of Basalt
and Dolomite is feasible
60% Basalt / 40% Dolomite
satisfy the PSV>=48 Limit 18

18. Paving of a 4km experimental project -DESIGN (1)
2 Dolomite sources (quarries)
1 Basalt source (quarry)
2 HMA types ( SMA, “S-
Structural”)
8 Mixtures 19

19. Paving of a 4km experimental project -DESIGN (2)
SMA “BLENDS” 20

20. Paving of a 4km experimental project -DESIGN (3)
S-Str “BLENDS” 21

21. Paving of a 4km experimental project -DESIGN (4)
PROJECT LOCATION (historical) 22

22. Paving of a 4km experimental project -DESIGN (5)
PROJECT LOCATION (2011)
ROAD 784 23

23. Paving of a 4km experimental project -DESIGN (6)
Total Production Tons
Experimental Test Sections –
B-D Blending tons
Total project length- about 4 Km
Overlay project- mill/overlay –
5 cm 24

24. Paving of a 4km experimental project - CONSTRUCTION (1)
NO production problems
NO workability difficulties
NO problems in controlling
proportioning – production &
QA/QC 25

25. Paving of a 4km experimental project - CONSTRUCTION (2)
AGGREGATE EXTRACTION
THE “ZEBRA” MIX

26. Paving of a 4km experimental project - CONSTRUCTION (3)
BOTTOM LINE –
EXCELLENT
CONSTRUCTION QUALITY ACHIEVED! 27

27. Paving of a 4km experimental project - CONSTRUCTION (4)
Z-SMA
Z-SMA
B-SMA 28

28. Performance monitoring of test sections(1)
MONITORING PROGRAM
Z-SMA
SURFACING AGE (MONTH)
MPD
SAND PATCH
PENDULUM
GRIPTESTER MK2
ROAR 16 + 28
ROAR - 75 KM/H , 86% FIXED SLIP, 0.5 mm
GRIPTESTER- 75KM/H, 0.5 mm 29

29. Performance monitoring of test sections(2)
MU- SMA MIXTURES – 16 Months - ROAR
Z-SMA 30

30. Performance monitoring of test sections(3)
MU- S- Str MIXTURES – 16 Months - ROAR
Z-SMA 31

31. Performance monitoring of test sections(4)
MU- S- Str MIXTURES – 16 Months – GT-MK2
Z-SMA 32

32. Performance monitoring of test sections(5)
SMA MIXTURES – 16 Months - MPD
Z-SMA 33

33. Performance monitoring of test sections(6)
S- Str MIXTURES – 16 Months - MPD
Z-SMA 34

34. Performance monitoring of test sections(6)
MU - ALL MIXTURES – 16 / 28 Months
Z-SMA
MU –
ROAR
16 MONTH
MU – GT – MK2 , 28 MONTH 35

35. Performance monitoring of test sections – conclusions (6)
The blended (“ZEBRA”) mixtures are:
Superior in friction performance to dolomite mixtures
Close in friction performance to basalt mixtures
These findings are valid after 2.5 years service period in medium trafficked road (AADT=15000)
There is no effect of aggregate type on texture depth
Z-SMA 36

36. Implementation in INRC paving projects (from 2010)
Updating Design Guidelines:
“ZEBRA” mixtures may be used in roads with an
AADT of 5000 to 20,000, or in other roads (with less
traffic) that require improvement in the SR
Basalt mixtures are required only for roads with
AADT of over 20000
“ZEBRA” mixtures are included in the INRC general
specs 37

37. Summary & Conclusions (1)
Controlled blending of high and low PR
aggregates is an accepted procedure
internationally
Laboratory PSV tests, established the
feasibility of 60% Basalt / 40% Dolomite
blending ratio 38

38. Summary & Conclusions (2)
Constructing a four kilometer test section with
various HMA mixtures: Basalt, Dolomite and 60%-40
% Basalt-Dolomite ("ZEBRA" ) blend demonstrated
that the " ZEBRA " mixtures met the all acceptance
specification requirements – similar to other control
mixtures.
Field performance monitoring proved that the SR of
the " ZEBRA " mixtures was superior to the
Dolomite's and close to Basalt's. 39

39. Summary & Conclusions (3)
Based on these findings, the " ZEBRA "
mixtures were introduced to the INRC's
specifications and design guidelines.
It is estimated that applying the new
design guidelines may save about
tons of basalt aggregate-
annually. 40

40. THANK YOU…