A critical review of commonly used bituminous paving mixes has attempted based on Mix selection based on function and location within flexible pavement. Capabilities of present day hot mix asphalt plants

1. A REVIEW OF BITUMINOUS
PAVING MIXES
Presented by,
NISCHAY.N
B.E(CIVIL)., M.Tech., IGBC-AP.

2.  The bituminous paving mixes have
evolved in 1960 as specified in MORTH
Specification.
 A critical review of commonly used
bituminous paving mixes has attempted
based on
 Mix selection based on function and
location within flexible pavement.
 Capabilities of present day hot mix
asphalt plants.

3.  PROVIDE STRUCTURAL STRENGTH
 FACILITATE SUBSURFACE DRAINAGE
 PROVIDING SURFACE FRICTION
ESPECIALLY WHEN WET

4. TYPICAL C/S OF PAVEMENT IDEAL C/S OF PAVEMENT

5. PERMEABLE ASPHALT TREATED BASE CONNECTED TO PAVEMENT EDGE DRAIN

6. REDUCE SPLASH AND SPRAY .
REDUCE TYRE-PAVEMENT NOISE.
ENHANCE VISIBILITY OF PAVEMENT MARKINGS, AND
REDUCE NIGHTTIME SURFACE GLARE IN WET WEATHER.
OGFC REPORTEDLY PROVIDES THE FOLLOWING
ADVANTAGES:

7. PREMATURE OGFC RELATED DISTRESS ON A
HIGHWAY
A VIEW OF RUTTING ON PAVEMENT

8. FOLLWING BITUMINOUS PAVING MIXES SPECIFIED
IN THE MORTH SPECIFICATION
BITUMINOUS MACADAM (BM)
DENSE BITUMINOUS MACADAM (DBM)
SEMI-DENSE BITUMINOUS CONCRETE (SDBC)
BITUMINOUS CONCRETE (BC)

9. FLEXIBLE PAVEMENT WITH BM AS
A BASE COURSE OR PCC
FLEXIBLE PAVEMENT WITH BM
AS A BASE/ BINDER COURSE

10. BM AND DBM SHOULD BE COMPARED BY
CONSIDERING FOLLOWING FACTORS:
PERMEABILITY
STRUCTURAL STRENGTH
USE OF PCC
COST CONSIDERATIONS
TRAFFIC CONDITIONS

11. PERMEABILITY:
BM IS A HIGH PERMEABLE MIX WHEN COMPARED TO DBM
OPEN SURFACE TEXTURE OF BM GRADING1 AND GRADING2 RESPECTIVELY

12. Mix Type Bitumen content,
%
Air Voids, % Permeability,
cm/sec
BM
Grading1(Coarse)
3.25 13.6 3.4
BM Grading1
(Fine)
3.25 8.9 0.4
BM
Grading2(Coarse)
3.4 15.4 3.6
BM Grading2
(Fine)
3.4 8.3 0.6

13. ROAD FAILURE IN OKLAHOMA,US RESULTING FROM
SATURATED BINDER COURSE
STRIPPED BINDER COURSE IN NH48 IN INDIA

14. STRUCTURAL STRENGTH:
DBM IS FAR SUPERIOR THAN BM IN TERMS OF STRUCTURAL
STRENGTH , MIX DESIGN CRITERIA, AND MIX PRODUCTION
CONTROL.
USES AS A PCC:
BM IS A GOOD MATERIAL FOR PCC BECAUSE IT RESISTS
REFLECTION CRACKING.
COST CONSIDERATIONS:
ACCORDING TO THE CURRENT PREVAILING SCHEDULE, THE
COST OF BM LAYER IS Rs.3,465/Cu.m WHERE OF DBM IS Rs.4,193/Cu.m.
THAT IS BM IS CHEAPER THAN DBM.
TRAFFIC CONDITIONS:
ACCORDING TO SOME HIGHWAY ENGINEERS, BM IS
INTENDED FOR LOW TRAFFIC ROADS ONLY.

15. DBM IS SPECIFIED FOR USE AS A BASE COURSE AND/OR BINDER COURSE.
TWO GRADATIONS ARE SPECIFIED IN MORTH SPECIFICATIONS:
GRADING1 HAS A NMAS OF 37.5mm
GRADING 2 HAS A NMAS OF 25mm
GRADING 1 OF DBM IS HIGH PERMEABLE ,IT SHOULD BE SEALED BEFORE
RAINY SEASON, OTHERWISE IT WILL PENETRATE AND DAMAGE WMM .
DBM GRADING 2 OF WITH 25mm NMAS IS SUITED FOR A BASE COURSE.

16. IT IS NEITHER DENSE GRADED NOR OPEN GRADED,CONTAIN THE SO
CALLED PESSIUM VOID WHEN CONSTRUCTED.
THE REGION BETWEEN B AND C IS PESSIUM VOID RANGE, IT
REPRESENTS OPPOSITE OF OPTIMUM.THE OBJECTIVE IS TO STAY OUT
PESSIUM VOID RANGES

17. THERE IS A NEED TO SELECT A BINDER COURSE AND TWO WEARING
COURSE. BC GRADING 1 WITH NMAS OF 19mm IS SUITABLE FOR A
BINDER COURSE. BC GRADING 2 WITH NMAS OF 13mm IS SUTABLE FOR
A WEARING COURSE ON HEAVY TRAFFIC ROADS.
THERE IS A NEED TO ADD A THIRD BC GRADATION WITH NMAS OF
9.5mm.
BC GRADING 1&2 NEED TO BE REVISING TO MAKE IT MORE RUT
RESISTANT

18. NCAT TEST TRACK IN AUBURN UNIVERSITY WHERE TRUCKS WITH
LOADED TRAILERS APPLYING TRAFFIC USING SPECIFIED BC COURSES

19. Grading Proposed DBM
Base course
Grading 1
Proposed DBM
Base course
Grading 2
Proposed BC
Binder Course
Proposed BC
wearing course
Grading 1
Proposed BC
wearing course
Grading 2
Lift thickness 75-100mm 75-100mm 50-75mm 30-50mm 25-40mm
NAS 37.5mm 25mm 19mm 12.5mm 9.5mm
Sieve size, mm Per cent passing
45 100 - - - -
37.5 90-100 100 - - -
26.5 63-93 90-100 100 - -
19 - 71-95 90-100 100 -
13.2 55-75 56-80 66-86 90-100 100
9.5 - - 55-75 70-88 90-100
4.75 38-54 38-54 35-55 53-71 55-75
2.36 28-42 28-42 28-44 38-54 40-55
1.18 - - 20-34 24-38 29-44
0.6 - - 15-27 17-29 21-33
0.3 7-21 7-21 10-20 12-22 14-25
0.15 - - 5-13 7-15 7-15
0.075 4-7 4-7 4-7 4-7 4-7
Bitumen
Content
4.0-5.5 4.0-5.5 4.0-5.5 5.0-7.0 5.2-7.5

20. IT IS NOT NECESSARY TO USE ALL THREE COURSES
IN A NEW FLEXIBLE PAVEMENT UNLESS THE
TRAFFIC IS VERY HIGH.
FOLLOWING ARE THE COMBINATIONS OF
BITUMINOUS PAVING
MIXES:
WMM + DBM BASE COURSE + BC BINDER COURSE + BC
WEARING COURSE.
WMM + BC BINDER COURSE + BC WEARING COURSES.
WMM + BC WEARING COURSE ONLY.

21. FOR ENSURING LONG TERM PERFORMING PAVEMENTS, FOCUS
SHOULD SHIFT TO DENSE GRADED RATHER THAN OPEN GRADED
BITUMINOUS MIXES.
THE STUDY RECOMMENDS IN TOTAL 5 NUMBERS OF BITUMINOUS
MIXES:
37.5mm NMAS,DBM BASE COURSE GRADING1
25mm NMAS,DBM BASE COURSE GRADING2
19mm NMAS BC BINDER COURSE
12.5mmNMAS BC WEARING COURSE GRADING1
9.5mm NMASBC WEARING COURSE GRADING 2
REASERCH IS GOING ON FOR THE USE OF LARGE NMAS IN
DBM AND CORRECTIONS MUST BE MADE AFTER ITS
COMPLETION ON THE NMAS OF EACH COURSE IF RESULTS
ARE POSITIVE.

22.  BITUMINOUS MACADAM IS HIGHLY PERMEABLE AND
NOW IT IS SUBSTITUTED BY DBM
USE OF THICK WEARING COURSE IS RECOMMENDED
FOR TROPICAL COUNTRY ONLY.
BM USED AS PCC IS DISCOURAGED AND NOT ALLOWED
NOW A DAYS.

23. i. JURNAL OF INDIAN ROAD CONGRESS
(vol. 69-2, jul-sep-2008)
ii. www.Oklhoma.com
iii. Bureau of Indian standard IS 73: 2006, jul-
2009

24. ?
QUESTIONS

25. THANK YOU