NCDOT Experience with Diamond GrindingDiamond Grinding

John Depman

International Grooving and Grinding Association

L i Obj iLearning Objectives

d d dIntroduction to Diamond GrindingAdvantages, Benefits and UsePerformance and CostsNCDOT ProjectsSummary

What is Diamond Grinding?What is Diamond Grinding?

Removal of thin surface layer of hardened Removal of thin surface layer of hardened PCC using closely spaced diamond saw blades;R lt i th l l t fResults in smooth, level pavement surface;Longitudinal texture with desirable friction and low noise characteristics;Frequently performed in conjunction with other CPR techniques, such as full-depth repair, dowel bar retrofit, and joint resealing.repair, dowel bar retrofit, and joint resealing.Comprehensive part of any PCC Pavement Preservation program;

Diamond GrindingDiamond GrindingCutting Head

Diamond GrindingDiamond GrindingDimensions

Diamond GrindingWidth of diamond blades(.10 to .125 inches)

Land area - .080 inches for hard aggregate- .110 inches for soft aggregate

GrindingGrinding

Diamond GrindingDiamond GrindingGrinding Machine

Diamond GrindingDiamond GrindingGrinding Process

Diamond GrindingDiamond GrindingFinished Product

Diamond Grinding Was Invented in California

Diamond grinding was first used in California in 1965 on a 19-year old section of I-10 to eliminate significant faulting (Neal and eliminate significant faulting (Neal and Woodstrom 1976). In 1983, CPR was conducted on this same pavement section including the use of pavement section, including the use of additional grinding to restore the rideability and skid resistance of the surface. In 1997, the process was repeatedthe process was repeated.Since its first use in 1965, the use of diamond grinding has grown to become a major l t f PCC t tielement of PCC pavement preservation.

Effectiveness of Diamond Grinding -gCALTRANS

STATE OF CALIFORNIA

CALTRANS has determined that the average life of a diamond ground

STATE OF CALIFORNIADEPARTMENT of TRANSPORTATION

DIVISION OF ENGINEERING SERVICES

MATERIALS ENGINEERING

AND TESTING SERVICES

pavement surface is 17 years and that a pavement can be ground at least th ti ith t

OFFICE OF RIGID PAVEMENT AND STRUCTURAL CONCRETE

5900 Folsom Boulevard

Sacramento, California 95819

three times without affecting pavement structurally. See IGGA.net for full reportfor full report

THE EFFECTIVENESS OF DIAMOND GRINDING

CONCRETE PAVEMENTS IN CALIFORNIA

November 2004

Advantages of Diamond Grinding

C t b t ti ll l th AC lCosts substantially less than AC overlays;Enhances surface friction and safety;Can be accomplished during off-peak hours with p g pshort lane closures and without encroaching into adjacent lanes;Grinding of one lane does not require grinding of Grinding of one lane does not require grinding of the adjacent lane;Does not affect overhead clearances underneath bridges;bridges;Blends patching and other surface irregularities into a consistent, identical surface;Environmentally friendlyEnvironmentally friendly.

Pavement Problems Addressed

Faulting at joints and cracksBuilt-in or construction roughnessPolished concrete surface Polished concrete surface Wheelpath ruttingPermanent upward slab warpingp p gInadequate transverse slopeUnacceptable noise level

Faulted Joints

Diamond grinding can provide a 60% to 70% Diamond grinding can provide a 60% to 70% improvement over the pre-grind profile on average!

Safety

Polished Surface

Safety, Surface Texture and Friction

Increased macrotexture of diamond ground Increased macrotexture of diamond ground pavement surface provides for improved drainage of water at tire-pavement interfaceLongitudinal texture provides directional Longitudinal texture provides directional stability and reduces hydroplaning (side-force friction) Grooves provide “escape route” for water trapped between tire and pavement water trapped between tire and pavement surfaceIn Wisconsin, overall accident rates for ground surfaces were 40% less than for un-gground surfaces over a 6-year period, 57% in wet weather conditions(Drakopoulos et al. 1998)

Safety

I d f di d d Increased macrotexture of diamond ground pavement surface provides for improved drainage of water at tire-pavement interfacedrainage of water at tire pavement interfaceGrooves provide “escape route” for water trapped between tire and pavement surfaceReduces the potential for hydroplaning

Wheel Path Rutting

C liCurling

Unacceptable Noise Level

Traffic Control

Traffic Management

Minimal traffic control requiredPerform off-peak hoursShort closures - re-open lanes as neededNo equipment encroachment into other q planesCan do just one lanejDoes not affect overhead clearances

P fPerformance

Diamond Grinding StudyDiamond Grinding StudyBy ERES

2 64 2 (5)(11)(7) (10)

62

21

5

( )

1(2)(10)

(10)( )

1

( )

(1)

(10)(6)

(3)

1

3 4

1 1

5 6(2)(2)(12)

(4) (4)(27)

( )

6(1)

(27)

(4)

AASHTO Design Model Prediction vs. Actual Traffic

60 AASHTO d i d l di i (50% li bili )

50

60 AASHTO design model prediction (50% reliability)Cumulative traffic (construction to grinding)Total traffic since initial construction

Ls

30

40

ion

ESA

L

20

30

affic

, mill

i

0

10Tra

0FL I-10 AL I-20 NC I-26 SC I-85 GA I-75 GA I-85

Diamond Grinding StudyDiamond Grinding StudyBy ERES

d l fExtends service life;Initial smoothness comparable to

lnew pavement or overlay;Average life of 32 years;May be reground 3 to 4 times;

Effectiveness of Diamond Grinding -gCALTRANS

STATE OF CALIFORNIA

CALTRANS has determined that the average life of a diamond ground

STATE OF CALIFORNIADEPARTMENT of TRANSPORTATION

DIVISION OF ENGINEERING SERVICES

MATERIALS ENGINEERING

AND TESTING SERVICES

pavement surface is 17 years and that a pavement can be ground at least th ti ith t

OFFICE OF RIGID PAVEMENT AND STRUCTURAL CONCRETE

5900 Folsom Boulevard

Sacramento, California 95819

three times without affecting pavement structurally. See IGGA.net for full reportfor full report

THE EFFECTIVENESS OF DIAMOND GRINDING

CONCRETE PAVEMENTS IN CALIFORNIA

November 2004

Noise Performance

So what is all this noise about diamond diamond grinding in Arizona?!?Arizona?!?

Typical ARFC Noise Research Results - ADOT

“The results shown “The results shown represent the average of twenty projects. The projects were located on I-p j8, and I-10, and ranged in age from three years to twelve years. The regression indicates

AR_ACFC Noise Levels Versus Pavement Age

y = 0.5453x + 93.279R2 0 5805

100

101

102

A regression indicates approximately a 5 dBA increase in noise generation in a ten year period. The

R2 = 0.5805

96

97

98

99

CPX

Noi

se L

evel

s dB

A

current data further indicates that AR-ACFCs typically range from 94 to 99 dBA throughout their

93

94

95

0 2 4 6 8 10 12 14

Pavement Age

C

99 dBA throughout their life.”

California and Arizona PCCP SI Test Results

Diamond Grinding - The Long Life g gSolution to Tire/Pavement Noise

Costs

Depends on —Aggregate and PCC mix properties;Average depth of removal;Smoothness specifications;Si f h jSize of the project;Work schedule;

Cost effective whether used alone or as part of a comprehensive CPR program. In most cases, the cost of diamond grinding is only about half the cost cost of diamond grinding is only about half the cost of bituminous overlay.

Costs

Soft limestone — as low as $1.50 per sq. yd.

Hard river gravel — as high as $10.00 per sq. yd.

Typical price — $2.00 to $4.00 per sq. yd.

*for a job with min. 20,000 sq. yds. and reasonable traffic control requirementscontrol requirements

Evaluate Rideability

Rainhart profilograph (or similar) Take traces before and after grindingShould be able to provide 60% to p70% improvement over pre-grind profileVerify profile index against specification requirement

NCDOT Projects – Reasons for DG

) I 85 in Salisbury (Ride quality)A) I-85 in Salisbury (Ride quality)B) I-95 North of Henderson (Rehab)

I 40 i O /D h C i (R h b)C) I-40 in Orange/Durham Counties (Rehab)D) I-77 in Yadkin Co. (DB as benefit to

NCDOT)NCDOT)E) I-26 in Hendersonville (Rehab)

US1 i CF) US1 in Cary (Included in Contract due to work)

G) NC 147 in Durham (Rehab)H) WWF (NCTA Project) (Noise Reduction)

I-40 in Orange/Durham CountiesDG as part of PCCP rehabilitationCompleted in 2011

NC 147 in Durham ($2.60/SY)DG as part of PCCP rehabilitationCompletion in early 2012

NCTA: WWF project in Wake Countyp j y

DG entire project for noise reductionCompletion date December 2012Completion date December 2012

NCDOT DG Projects IRI ResultsNCDOT DG Projects – IRI ResultsLocation IRI (avg) – IRI (avg) –

Before DG After DG

I-85 102.4 55.0

I 95 116 2 46 5I-95 116.2 46.5

I-40 (2010) 102.7 61.9

I-77 (DB – 2009) 112.6 61.0

I-26 99.3 (Faulting) 75.4

US 1 (2006) 94.9 60.8

NC 147 (2012) 121.4 57.0

WWF (2013) 38.9

It’s a Fact!

Diamond grinding can provide fthe safest, smoothest, most

quiet PCC pavement texture available when properly designed and constructed with gdurable aggregates!

FHWA T h i l Ad iFHWA Technical Advisory

TA 5040 36 S f T t F TA 5040.36 Surface Texture For Asphalt And Concrete Pavements

State Of Practice Surface Texture - State Of Practice Surface Texture includes diamond ground surfaces for new pavementsp- Technique Recommended Application- Factors For Selecting Texture TechniquesS IGGA N f f TA See IGGA.Net for a copy of TA 5040.36

Summary

Di d i di t d t lif Diamond grinding can extend pavement life significantly at a competitive cost.Diamond grinding is a key Preventive Maintenancetool.Diamond grinding will increase customer satisfaction, increase friction, reduce noise and satisfaction, increase friction, reduce noise and reduce life cycle costs.Performance and cost vary with given conditions. Ti i i thiTiming is everything.ACPA and IGGA are ready to assist!