28 rpf eden maint gvz

Road Pavement Forum13 14 May 2009

Gerrie van Zyl &Hans Ottervanger

Optimisation of gravel road maintenance

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Quality Gap

SA Road User Perception

600 000 km

150 000 km

ROAD MANAGEMENT SYSTEM RESULTSF

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Road User Response

AFRICA SPEED TRAP

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Quality of Service

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Current drive in southern Africa

Quick survey on LVSR in SA

AREA Kilometres

Formal Transvaal Province (Now incorporating Gauteng,Mpumalanga, Limpopo, North West)

+800

Western Cape + 500

Kwazulu Natal +1000

Free State + 300

2001

Western Cape improvement strategy17 Actions initiated including

Assistance (Appointment of 5 Consultants) Management Upgrading of the Gravel Road Management System Development of Gravel Management System Keeping track of productivity and cost

Road and material design Borrow pit investigation Formal design and approval

Construction Training Quality control Trial sections Processes & Equipment

Material selection & mechanical modification

TRH 20 Classification

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Grading Coefficient

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TRH 20 Classification

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Ravel & Corrugate B

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DSlippery

AErodible

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Good (Dusty)

Shrinkage product (Sp) = % linear shrinkage x % passing 0,425 mm sieve

Grading coefficient (Gc)= ([% passing 26,5 mm % passing 2,0 mm]x % passing 4,75 mm) / 100

Construction Plant & Quality Control

Plant and Equipment: NowPlant and Equipment: Now

Construction: Quality & ControlConstruction: Quality & Control

Plant and Equipment: ThenPlant and Equipment: Then

Construction: Place & Go!Construction: Place & Go!

Controlled Construction Processes

Effective Grid rollingEffective Grid rolling Remove Oversize ManuallyRemove Oversize Manually

Wet Rolling (Slushing)Wet Rolling (Slushing)Pneumatic Roller Final CompactionPneumatic Roller Final Compaction

Wearing Course Finish

Improved Grading Improved Grading

Excellent Riding QualityExcellent Riding QualityCompaction at OMC Compaction at OMC

Poor GradingPoor Grading

Drainage

Drainage: ThenDrainage: Then Drainage: NowDrainage: Now

Borrow Pit Development, Mining & Rehabilitation

Public ParticipationPublic Participation Borrow Pit RehabilitationBorrow Pit Rehabilitation

Environmentally friendly toiletsEnvironmentally friendly toiletsImproved Mining TechniquesImproved Mining Techniques

PERFORMANCE MONITORING

Visual assessment of distress development and progression Roughness measurement Gravel loss and shape change measurement Structural capacity Change in material properties

2.25 L

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Relative Height

Offset (m)

Stake Value

DR1318

Impact on gravel loss

DR1303(30-30.5)

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Actual HDM4 TRH20Gravel Loss less than 50% of predicted

DR1303(30-30.5)

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Actual HDM4 TRH20Gravel Loss less than 50% of predicted

OBSERVATIONS AND IMPLICATIONS Much slower roughness deterioration than predicted

AADT = 66, 17% heavyMR270: km32 - 32.5: Roughness Deterioration (Model vs. Actual)

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Actual QI HDM Blading (Normal compaction)

Improved performance directly related to savings in VOC

EFFECT OF IMPROVEMENTS IMPLEMENTEDEFFECT OF IMPROVEMENTS IMPLEMENTED

TotalCosts

RoadNetwork

Costs

RoadUserCosts

Area of minimum transportation costs

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Road Network Quality GoodPoor

15% p.a. min. return

on investment

30% additional

costs

Materials & Control

Formation & Drainage

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20 %

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Maintenance strategy changed

MR276: km1.8 - 2.3: Roughness Deterioration (Model vs. Actual)

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Actual QI HDM Adjusted Constr f=0.8 HDM Blading (normal compaction)

Effect of reshaping(Adjusted model)

AADT = 323, 19% heavy(2001)

Reshaping more economic than continuous blading at high roughness levels

AADT > 500(2007)

CONCLUSIONS ON LIGHT BLADING Correct regular light blading prevents rapid deterioration Confirm NO deterioration as a result of blading The effect of light blading not simulated by current models More than double the frequency of hard blading, but blading at

higher speed (up to 70 blade km per day) Applicability of light blading strategy dependent on quality of

construction and suitability of available maintenance material

Average Roughness Deterioration: MR584

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TRH20 Average Measured HDM4

AADT = 86, 14% heavy

Eden drive towards optimising blading strategy

Task team under J Strydom & H Ottervanger Workshop on blading best practice Field visits Obtain all available information from WCPA Categorise road network Workshop to formulate best strategy Documentation Implementation Training

Light blading

Remove cohesionless material

Spread fine material (moist & slightly plastic)

Grading/ Hard Double Blading

Grading/ Heavy BladingTypically < 50 mm distress/ deformationMoistenLoosenRestore shape Roll

Reshape/ Rework Reshape/ Rework i.e.

reconstruct wearing course layer using the existing materialDrainageRipMoistenBreak down/ remove oversizeShape Compact

ROAD USER COSTS

AGENCY COSTS

TIME COSTS

ACCIDENT COSTS

MAINTENANCE COSTS

CONSTRUCTION COSTS

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IRI (mm/m)

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Cars (HDM4)HVeh. (HDM4)Bus (HDM4)

Cost components Direct relationship between VOC and Riding Quality

VEHICLE OPERATING COSTS

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Reshape

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Regular light blading

Occasional hard blading

Eden drive towards optimising blading strategy

Task team under J Strydom & H Ottervanger Workshop on blading best practice Field visits Obtain all available information from WCPA Categorise road network Workshop to formulate best strategy Documentation Implementation Training

Define network

Determine/ Allocate Grader Productivity per road/ area

Unit Costs

Determine Min & Appr. Blading type, Blade passes, Blade km/ maint sect per annum

Define Uniform Maintenance sections

Define Minimum & Appropriate LOS

Determine minimum & appropriate blading frequency and adjust

Appropriate FundingRequirement

Min Fund Required

Combine maint sections to obtain balanced Distribution per Ward/ Maint Area

Grader requirementsStrategies

Distribute blading requirements to balance cycles: Blading Schedules

Fund allocation

Recalculate affordable blading frequency per maintenance section

Verify monthly program on site & issue

Feedback

Funding model (Reallocation)

50% 20% 20% 10%

40% 20% 20% 20%

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Results after implementation

Well defined monthly programs Major reduction in complaints Positive feedback from communities/ RU Ability to adjust blading programs with

reduced/ increased funding

Monthly program issued to operatorWYK: Odn Wes Bertus Hartzenberg Hoeveelheid werksdae vir operateur in maand: 16

Beplande lem km vir maand: 320

VAN TOT

1 DR01649 Paardebont 0.00 3.42 14 Ligte dro skraap



1 DR01656 Saffraanrivier 0.00 12.36 49 Ligte dro skraap

1 DR01677 Zeekoegat/Wynands 0.00 11.18 45 Ligte dro skraap

1 DR01693 Steenoondepad 0.60 12.37 47 Ligte dro skraap

DR01655 Mount Hope 0.00 4.00 16 Ligte dro skraap

DR01655 Mount Hope 4.00 11.50 30 Ligte dro skraap

Totale Beplande Lem km vir die maand: 357

Nota: Operateur moet in opmerking kolom die skraaptoestande beskryf Bv Nat, Baie droog, Stofgate ens.

Operateur moet datum waarop seksie afgehandel is in afgehandel kolom skryf.

Die Vorm moet aan die einde van elke maand ingehandig word by die supt.

Operateurs inligting:

Van Tot

1-Jul-08 Padskraper operateurs vergadering

23-Jul-08 Spanbesoeke met Gert,Alvin,Maevia,Reginald

28-Jul-08 31-Jul-08 Nqf 4 kursus

TAAKBESKRYWING

LEM KM TAAKBESKRYWING

Addisionele inligting rondom staantyd, soos reen, werktuig breek, operateur siek ens.

EDEN DISTRIKSMUNISIPALITEIT: DEPARTEMENT TEGNIESE DIENSTEMAANDBEPLANNING: JULIE 2008

SIKLUSPAD

NOMMER PAD NAAMKILOMETER AFSTAND

OPMERKING AFGEHANDEL

Datum

Results after implementation

Well defined monthly programs Major reduction in complaints Positive feedback from communities/ RU Ability to adjust blading programs with

reduced/ increased funding Ability to manage emergency work

Note: Process verified with other authorities TRH20

Emphasis now on training (DVD)

END

June 5, 2009 Slide 39

Quality GapROAD MANAGEMENT SYSTEM RESULTSRoad User ResponseAFRICA SPEED TRAPQuick survey on LVSR in SA2001Material selection & mechanical modificationConstruction Plant & Quality ControlControlled Construction ProcessesWearing Course FinishDrainageBorrow Pit Development, Mining & RehabilitationPERFORMANCE MONITORINGImpact on gravel lossOBSERVATIONS AND IMPLICATIONSMaintenance strategy changedCONCLUSIONS ON LIGHT BLADINGEden drive towards optimising blading strategyLight bladingGrading/ Hard Double BladingReshape/ ReworkEden drive towards optimising blading strategyFunding model (Reallocation)Results after implementationMonthly program issued to operatorResults after implementationEND

28 rpf eden maint gvz

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