1. MICROSURFACING AS ECO FRIENDLY TECHNOLOGY FOR MAINTENANCE Dr. Sangita Senior Scientist Flexible Pavement Division CENTRAL ROAD RESEARCH INSTITUTE NEW DELHI

2. PURPOSE OF MAINTENANCE Improvement of Riding Quality Retardation of Deterioration Process Extension in Service Life of Pavement Saving in Road User Cost Reduction in Environmental Damage by Reduced Fuel Consumption Avoidance of Large Capital Investment for Reconstruction

3. SUGGESTED NORMS  To prevent noise and air pollution when road maintenance is in progress  Utility levels to be kept at the existing levels (increase in height of pavement to be discouraged)  General road users should not be disturbed while maintenance is in progress  Keeping in view above points microsurfacing is an environment friendly maintenance technology.

4. MICROSURFACING Microsurfacing is a mixture of Polymer Modified Emulsified Bitumen, Dense Graded Crushed Mineral Aggregates, Mineral Filler (normally Portland Cement), Water and Chemical Additives to facilitate early setting of mix. Microsurfacing in Progress

6. ADVANTAGE OF MICROSURFACING Quick setting Early opening to traffic Higher resistance to abrasion Can be used for Medium volume traffic corridors Fast construction Less air/noise pollution Cost effective

7. ADVANTAGE OF MICROSURFACING (Contd.) Prevents reflective cracking Seals wide cracks effectively Delays in hardening of bitumen due to environment Better visibility at night No rolling and compaction is required Preservation of pavements’ structural strength

8. ADVANTAGES OF MICROSURFACING  Marginal raise in pavement height  Least environment pollution  Increased skid resistance  Faster laying process  High durability due to polymer / rubber additives

9. APPLICATIONS  Preventive and periodic maintenance  Rut filling with the help of special rut box  Improvement in skid resistance and friction on a concrete road  Filling up of minor irregularities on surface

10. Quality Control Tests Polymer Modified Emulsion Storage Stability Grading of Filler. Grading of Aggregate Binder Content. Grading of Aggregate Recovered from Mix Residual Bitumen Content, % Wt. of dry aggregate Application Rate of dry aggregate

11. PROPERTIES OF MODIFIED EMULSION FOR MICROSURFACING RequirementsTest MethodLimits Viscosity Say bolt furol at 25 0 C, Sec.IS:888720-100 Particle chargeIS:8887Positive Storage stability (24 hours), %, max.IS:88871.0 Residue by evaporation, %, min.IS:888760 Test on Residue · Penetration, 0.1mm at 25 0 CIS:120340-90 · Softening Point, 0 C, min.IS : 120560 · Elastic Recovery, %, min.IRC : SP : 5320 · Ductility at 5 0 C, cm, min.IS:120820 · · Plasticity interval, min, 0 CIS : 988175

12. RequirementTest MethodLimits Sand Equivalent valueASTM D 241965% Minimum SoundnessIS: 2386 Part-515% Max. using Na 2 SO 4 25% Max. using Mg SO 4 Abrasion ResistanceIS: 2386 Part-430% maximum REQUIREMENT OF AGGREGATES

13. GRADING OF AGGREGATES FOR MICROSURFACING Sieve Size Type-II, Percent Passing Type-III, Percent Passing Stockpile Tolerance 9.5 mm100 -- 4.75 mm90-10070-90  5% 2.36 mm65-9045-70  5% 1.18 mm45-7028-50  5% 600 micron30-5019-34  5% 330 micron18-3012-25  4% 150 micron10-217-18  3% 75 micron5-15  2%

14. Mix Composition & Application Rate PropertyType IIType III Residual Bitumen Content, % Wt. of dry aggregate 7-135.5- 8.0 Application Rate of dry aggregate 6-118-12

15. Composition (by Weight of Aggregate) of various ingredients Composition (by Weight of Aggregate) of various ingredients Ingredients Type IIType III Aggregate100 Cement, %1.5 Water, %1414.5 Emulsion, %13.513 Additive,%As required

16. Calibration of machine Capt Gaur Marg Road 29K N Katju Marg Out Flow / Calibration Aggregate600kg/min Emulsion78kg/min81kg/min Cement9kg/min Additive9kg/min

17. Rate of Application on Capt Gaur Marg Length = 254.60 m Width = 2.60 m Travel Time = 11.19 sec Area = 661.96 Sq.cm Aggregate Consumed = (11+ 19/60)*600kg/min = 6790 kg Emulsion Consumed = (11+ 19/60)*78kg/min = 883kg Cement Consumed = (11+ 19/60)*9kg/min = 102 kg % Emulsion = 883/6790*100 = 13.0 % Cement = 102/6790*100 = 1.5% Rate of Application = 6790kg/661.96 Sq.m = 10.26 kg/Sq.m

18. REQUIREMENT OF MIX ISSA TestDescriptionSpecification ISSA TB-139Wet Cohesion @ 30 Minutes Minimum (Set) @ 60 Minutes Minimum (Traffic) 12 kg-cm Minimum 20 kg-Cm Minimum ISSA TB-109Excess Asphalt by LWT Sand Adhesion 540 g/m 2 Maximum ISSA TB-114Wet Stripping Pass (90% Minimum) ISSA TB-100Wet-Track Abrasion Loss One – hour Soak Six-day Soak 540 g/m 2 (maximum) 800 g/m 2 (maximum) (ISSA technical manual for slurry sealing and microsurfacing)

19. TESTSTANDARDUNITLIMITS ConsistencyASTM D:3910Cm2 – 3 Set timeASTM D:3910Minute15 – 240 Cure timeASTM D:3910Minute< 480 Loss on WTAT ASTM D:3910G/m 2 < 500 REQUIREMENT OF MICROSURFACING

20. USAGE OF MICROSURFACING  Useful on Flexible as well as Rigid Pavements  Application in thin layer (3-4 mm thick)  On top surface of flyovers and bridge decks  Approaches of junctions and roundabouts

21. BASIC CONDITIONS FOR APPLICATION OF MICROSURFACING  Pavement should be structurally sound for future traffic  Wide alligator cracks, transverse cracks should be repaired prior to application of microsurfacifng  All deep ruts in excess of 8mm shall be filled up before application of microsurfacing THE QUANTITY OF TREATMENT DEPENDS UPON :  Pavement Distress  Traffic  Loading

22. Serviceability IndicatorsUrban (Heavy Traffic) Urban (Light Traffic) PreventivePeriodicPreventivePeriodic Deflection*, mm0.8 (max.) 1.2 (max.) Distress, %5 (max)10 (max.)5 (max.)10 (max.) Roughness, mm/km.2500 (Max.)3500 (max.)3000 (max.)4000 (max.) Rutting, mm8 (max.)16 (max.)8 (max.)16 (max.) Thickness, mm5-67-83-46-7 Quantity of aggregate, kg/m 2 10-1214-166-812-14 Type of grading (ISSA)**III II *as measured with Benkelman beam, **International slurry seal association. Guidelines for Application of Microsurfacing

23. QUALITY CONTROL GUIDELINES Prior inspection and rectification of defects Inspection of machine and materials Calibration of machine Control of flow rate of ingredients as per mix design at site Removal of drag marks with rubber squeegee Control of joints (desirable 50 mm overlap)

24. SUGGESTED QUALITY CONTROL FREQUENCY TestFrequency Quality of aggregateOne test per source Grading of aggregates and moisture content One test per lot (100 tonne) Flow of aggregate from the machine Daily Quality of emulsionRegularly per lot (10 tonne) Binder content in mixOnce per day Grading of washed aggregateOnce per day Quality of water and cementOnce per source

25. Not applicable for air temperature below 10 0 C Applicable when pavement and air temperature are above 8 0 C and rising Not applicable when the finished product freezes within 24 hours WEATHER LIMITATIONS

26. Tack Coat Required only in case of extremely dry surfaces or concrete pavements Tack coat should consist of one part emulsified bitumen / three parts water Emulsified bitumen shall be slow setting grade Should applied with a standard distributor Distributor shall be capable of applying the diluted emulsion at a rate of 0.2 to 0.3 litre / m 2

27. COST ASPECTS OF MICROSURFACING IN COMPARISON WITH CONVENTIONAL HOT MIX RENEWAL PER LANE – KM (3500 M 2 ) IS :  40 mm Thick Bituminous Concrete ~ 5 lakhs  8 mm Microsurfacing ~ 3 lakhs SAVINGS IN LAYING OF MICROSURFACING  Aggregates ~ 75 % Unit cost/m 2  8 mm thick Microsurfacing ~ Rs.100  40 mm thick BC ~ Rs.  Savings ~ 35 %

28. WORKS EXECUTED IN DELHI The Microsurfacing technology has been recently introduced in India and following roads in Delhi has been resurfaced with this technology: Prithvi Raj Road Windsor Palace Roundabout August-kranti Marg Outer Ring Road Number 26 Joseph Tito Marg Ashram Flyover Obrai Hotel Flyover

29. VIEW OF ORR 26 BEFORE MICROSURFACING

30. FRESHLY LAID MICROSURFACING ON ORR 26

31. MICROSURFACING ON ORR 26 ONE WEEK SIX MONTHS

32. Nov. 2000 March 2001July 2003

34. STUDY FINDINGS There is improvement in riding quality Growth of roughness with passage of time is arrested Prevents moisture ingress Development of distress delayed Provides a sort of laminated layer on top of the existing road surface

35. SURFACE CONDITION OF NH-44 BEFORE TREATMENT

36. CALIBRATION OF MICROSURFACING PAVER IN PROGRESS

37. LAYING IN PROGRESS

38. TEXTURE OF FRESHLY LAID MICROSURFACING

39. SURFACE CONDITION AFTER 24 HOURS

40. NR Latex Modified bitumen emulsion12 % Aggregates100 % Cement2 % Additive1.5 % Water12 % TYPICAL COMPOSITION OF MICROSURFACING MIX

41. COMPARISON OF HOT MIX AND COLD MIX TECHNOLOGY ItemMicrosurfacingHot Mixed Bituminous Concrete Noise LevelLowHigh Production of Toxic FumesNoneHigh DustLowHigh Worker HazardNoneHigh Energy ConsumptionLowHigh Ease of ApplicationVery EasyNot so Ability to Resist WeatheringHighLow Flexibility of ProductHighLow Ability to Apply in Damp ConditionYesNo Thickness of Layer4-16 mm25-50 mm Cost per m 2 Rs. 100Rs. Life Time Expectancy4-6 Years

42. PWD has decided to resurface number of roads in Delhi using Microsurfacing. So far, the work has been executed on the following roads. PWD has decided to resurface number of roads in Delhi using Microsurfacing. So far, the work has been executed on the following roads. Siri Fort Road Link Road between NH-8 & Samalkha Chowk, Ambedkar Road New Delhi Road No. 29 Pashim Vihar Dr. K.N. Katju Marg Rohini Rao Tula Ram Marg Nizzamuddin Bridge to Noida More Road No. 42A Deepali Chowk, Rohini. Ashram Chowk to Nizzamudin Rajghat (Ring Road) Captain Gaur Marg 

43. Properties of Designed Mix RequirementsISSA LimitsContract Document Test Value Design Parameters Consistency (mm)20-30 24 Set Time, minutesMax 24015-24018 Cure Time, minutesMax 480 90 Loss on Wet Track Abrasion Test, g/m 2 538 (max)500 (max)43

44. Properties of Polymer Modified Emulsion used at various locations Properties of Polymer Modified Emulsion used at various locations S.No.Test Test Value Road No. 29 Pashim Vihar. Test Value DR. K.N. Katju Marg Rohini Specified Test Value as per contract document 1Residue on 600 micron IS Sieve, percent by mass 0.480.120.05, Maximum 2Viscosity by Saybolt furol Viscometer, Seconds at 25 0 C 212320-100 3Coagulation of Emulsion at low temperature Nil 4 Particle charge Positive 5Miscibility with waterNo Coagulation

45. Tests on residue 6Residue by evaporation, percent, 63.26560 Minimum 7Penetration 25 0 C/100g/5Sec 444540-90 8Ductility 5 0 C/cm,172610 Min 9Solubility in Trichloroethylene, percent by mass, Min 98.198.597.5 10Elastic recovery at 25 0 C,% 202812 Minimum

46. S.No.TestLink Road between NH – 8 & Samhalka Chowk Ambedkar Road Specified Test Value as per IS 8887:2004 1Residue on 600 micron IS Sieve, percent by mass 0.040.050.05, Maximum 2Viscosity by Saybolt furol Viscometer, Seconds at 25 0 C 232020-100 3Coagulation of Emulsion at low temperature Nil 4Particle chargePositive 5Miscibility with waterNo Coagulation

47. Tests on residue 6Residue by evaporation, percent, 62.36160 Minimum 7Penetration 25 0 C/100g/5Sec 404840-90 8Ductility 5 0 C/cm,151310 Min 9Solubility in Trichloroethylene, percent by mass, Min 97.89897.5 10Elastic recovery, 25 0 C,% 211612 Minimum

48. Grading obtained for mineral filler (Cement) Sieve (mm) Road No. 29 Pashim Vihar DR. K.N. Katju Marg,Rohini % Passing (specified) % Passing (obtained) 0.600100 0.300100 95-100 0.075919370-100

49. Sieve (mm)Link Road between NH 8 & Samhalka Chowk Ambedkar Marg% Passing (specified) % Passing (obtained) 0.600100 0.300989695-100 0.075999270-100

50. Gradation of aggregate (Type II) received from site Gradation of aggregate (Type II) received from site Sieve (mm) Road No. 29 Pashim Vihar. Dr. K.N. Katju Marg,Rohini % Passing (specified) % Passing (obtained) 9.5100 4.75969790-100 2.36626965-90 1.18566545-70 0.600425030-50 0.300202518-30 0.150141710-21 0.0758115-15

51. Sieve Size (mm) Link Road between NH-8 and Samhalka Chowk Ambedkar road Percent Passing (specified) % Passing (obtained) 9.5100 4.7596 90-100 2.36656365-90 1.18565445-70 0.600474430-50 0.300292818-30 0.150161410-21 0.075985-15

52. Sieve Size (mm) Road No. 29 Pashim Vihar DR. K.N. Katju Marg,Rohini Percent Passing (specified Type II) Percent Passing (obtained) 9.5100 4.75979890-100 2.3669 65-90 1.18656845-70 0.600515030-50 0.300252318-30 0.15017 10-21 0.07511125-15 Residual Bitumen,conent%8.68.17-13 Wet Track Abrasion Test g/square meter 1719 500 g/square meter max. Results of gradation of aggregate recovered from manufactured mix and Wet Track Abrasion Test

53. Sieve (mm) Link road between NH 8 & Samhalka Chowk Ambedkar road Percent Passing (specified, Type II) Percent Passing 9.5100 4.75969790-100 2.36666565-90 1.18545345-70 0.600444630-50 0.30028 18-30 0.150141510-21 0.0758105-15 PercentResidual Bitumen,Conent 7.68.17-13

54. QUALITY CONTROL AT THE JOB SITE Property tested at site Dr.K.N.Katju Marg,Rohini Road No. 29 Paschim Vihar. Specified Limits Residue in Emulsion 66.48 %64.6160 Minimum Sand equivalent 70.90%71.1 % 65 minimum

55. The specified grading and grading of stacked aggregate Sieve (mm) % Passing (obtained) Dr. K.N. Katju Marg,Rohini % Passing (obtained)Road No 29 Paschim Vihar % Passing (specified) 9.5100 4.75979590-100 2.36746765-90 1.18 647045-70 0.600434930-50 0.300302018-30 0.150161510-21 0.0755105-15

56. EXPERIENCE GAINED DURING EXECUTION EXPERIENCE GAINED DURING EXECUTION Precautions: (i) pre-matting of surface (ii) homogeneous mix to prevent segregation of the emulsion and aggregate fines. Difficulties experienced:  The residue retained on 600-micron sieve is higher than the specified limit. Remedial measure:  A 600-micron sieve should be used at the time of application.  Filler conforms the required specifications.  The gradation conducted on washed aggregate is within the specifications band except on 2.36mm sieve, it is slightly on the coarser side.

57.  Polymer modified emulsion needs special care during storage and transportation.  The hose used to pump the emulsion were ensured to be free of any materials that may contaminate emulsion.  Since, the storage stability of modified emulsion is relatively less as compared to conventional bitumen emulsion, it was used within a week from the date of production.  Materials like aggregate, water and emulsion were checked for compliance of specifications.  Continuous traffic flow caused hindrance in achieving desired output of machine in peak hours. Therefore the work could be executed between11 AM and 4.30 PM or during night

58. KN Katzu Marg Before Microsurfacing

64. KN Katzu Marg Microsurfacing Execution

76. KN Katzu Marg After Microsurfacing

89. Road No.29 Before Microsurfacing

95. Road No.29 After Microsurfacing

101. The technology has been demonstrated on eleven sections and various locations laid in Delhi. Area covered; 6.0 Lakh Sqm, Length ; 30 Km. approx Performance of these sections will be monitored for three years as a part of an in-house R & D project

102. CONCLUSIONS The ingredients and manufactured mix have complied to specifications cited in the contract document finalized by PWD, Delhi as well as ISSA specifications. Effective quality control plays a vital role in success of Microsurfacing projects. Microsurfacing could be an alternative to thin hot mix renewals in maintenance of urban roads in environment friendly manner and to save energy.

103. CONCLUSIONS Its an environmental friendly technology Energy efficient road maintenance technology Savings in the materials Cost effective application Completely mechanized operation Widely applicable for urban roads due to its ability in thin layer application Can cover large lengths in a day (a typical M.S. Machine can lay about 3.5 lane Km in 8 hours) Life expectancy is about 4-6 years

104. THANK YOU