Chapter 5 Diamond Grinding and Grooving - · PDF fileChapter 5 Diamond Grinding and Grooving ... light cars Chapter 5 – Diamond Grinding and Grooving. GroovingGrooving ... Module

Chapter 5Diamond Grinding and Grooving

From… Maintenance TechnicalAdvisory Guide (MTAG)

Learning Objectives1. List benefits of diamond grinding and

grooving2. Describe recommended diamond

grinding/grooving dimensions3. Describe recommended construction

procedures4. List important quality control activities5. Describe potential construction and

performance problems6. Identify troubleshooting solutions

Chapter 5 – Diamond Grinding and Grooving

Presentation Outline

IntroductionDesign considerationsConstructionQuality controlTroubleshooting


GrindingGrinding

Diamond Grinding

GrindingGrindingDiamond GrindingBenefits

Restored smoothnessImproved friction Improved cross slopeReduction in noiseImproved cross slope for reducing splash and spray


GrindingGrindingDiamond GrindingEffect on Roughness

Percent decrease in IRI

Test Area Lane 1 Lane 2 Lane 3

1 59% 56% NA

2 NA NA 53%

3 64% 60% NA

4 NA NA 55%NA = Not applicable


GrindingGrindingDiamond GrindingEffect on Friction

Percent increase in friction

Test Area Lane 1 Lane 2 Lane 3

1 25% 15% NA

2 NA NA 18%

3 41% 35% NA

4 NA NA 26%NA = Not applicable


GrindingGrindingDiamond GrindingProject Selection

Consider effectiveness and limitationsIGGA and ACPA recommendations• Present serviceability index (PSI) range of 3.8

to 4.0• Before critical faulting level

Used with other CPR activities



Traffic, ADT

Measure >10,0003,000 to 10,000 < 3,000

IRI, m/km (in/mi) 1.0 (63) 1.2 (76) 1.4 (89)

PSR 3.8 3.6 3.4

CA Profilograph, m/km (in/mi) 12 15 18



Ave. Faulting, mm (in) Comment

0.8 (1/32) No roughness

1.6 (1/16) Minor Faulting

2.4 (3/32) Grinding Project

3.2 (1/8) Expedite Project

4.8 (3/16) Discomfort Begins

6.4 (1/4) Grind Immediately


GrindingGrindingDiamond GrindingLimitations

Does not address structural or durability problemsHardness of aggregate affects costsRoughness will return if causes are not addressedAllowable work hours for the job can affect the cost


GrindingGrindingDiamond GrindingFollowing Load Transfer Restoration

GroovingGrooving

Diamond Grooving

GroovingGrooving

Diamond Grooving

Cutting parallel grooves into the pavement using diamond saw bladesLongitudinal vs. transverseBenefits• Improved wet weather friction• Reduction in splash and spray


GroovingGroovingDiamond GroovingProject Selection

Historical crash rate, friction number, or macrotexture depth dataPotential locations for wet weather crashesPavements should be structurally and functionally sound


GroovingGroovingDiamond GroovingLongitudinal Grooving

Advantages• Restored surface friction• Decreased hydroplaning potential• Improved curve tracking• Easier to conduct under traffic

Disadvantages• Perception poor handling for motorcycles and

light cars


GroovingGrooving

Transverse Diamond Grooving

GroovingGroovingDiamond GroovingTransverse Grooving

Advantages• Most direct channel for water drainage• Introduces a surface that provides significant

braking traction

Disadvantages• Maintaining adjacent traffic• Excessive noise• Productivity


GroovingGroovingDiamond GroovingEffect on Friction

10 20 30 40 50

5

10

15

20

•

•

•

•

2

•

••

1

3

4

6

•5

7

7½

8

9

•

•YEARS OF

OPERATION

MILLION VEHICLE PASSAGES/LANE

WET

PC

CP

AC

CID

ENT

RA

TE (A

CC

/MV

K)

Module 5-1

Design, Materials & Specifications





GrindingGrindingDiamond GrindingDesign Considerations

Degree of faultingReview past corrective effortsDesign specifications• Concurrent preservation techniques• Blade spacing• Transverse slope• Grinding limits and transitions


GrindingGrindingDiamond GrindingDimensions

Land area - varies depending on aggregate hardness2.0 mm typical for hard aggregate2.8 mm in typical for soft aggregate

Width of diamond blades(2.5 mm - 3.3 mm)


GroovingGroovingDiamond GroovingDesign Considerations

Groove entire lane areaAllowances for small areas with surface irregularitiesUse recommended blade spacing


GroovingGroovingDiamond GroovingDimensions

19 mm

3.2 mm min6.4 mm max

Saw blade thickness2.5 mm


Typical Item CodesItem Code Description

066145 Remove pavement markers074017 Prepare water pollution control program074020 Water pollution control074042 Temporary concrete washout (portable)120090 Construction area signs120100 Traffic control system128650 Portable changeable message sign413111 Repair spalled joints420201 Grind existing concrete pavement420102 Groove existing concrete pavement413114 Replace joint seal (existing concrete pavement)

http://i80.dot.ca.gov/hq/esc/oe/awards/#item_code

http://i80.dot.ca.gov/hq/esc/oe/awards/#item_code

Module 5-2

Construction and Inspection





GrindingGrindingDiamond GrindingConstruction Considerations

Grinding sequence and patternContinuous operationBegin and end perpendicular to centerlineMaximum overlap of 50 mm (2 in)Disposal of slurry


GrindingGrindingDiamond GrindingCutting Head Specifications

Diamond blades mounted in series on cutting headCutting head width from 48 to 50 inSpacing of 56 to 61 blades per ft


GrindingGrindingDiamond GrindingCutting Head

GrindingGrindingDiamond GrindingConstruction Procedures

Single lane closureConduct grinding parallel to centerlineMultiple passes per laneSlurry removal


GrindingGrindingDiamond GrindingGrinding Machine

GrindingGrindingDiamond GrindingGrinding Machine

GrindingGrindingDiamond GrindingTrucks Collecting Slurry

GrindingGrindingDiamond GrindingGrinding Process

GrindingGrindingDiamond GrindingFront of Grinding Head

GrindingGrindingDiamond GrindingBehind the Grinding Head

GrindingGrindingDiamond GrindingAfter First Pass of Grinding Machine

GrindingGrindingDiamond GrindingFinished Product

GroovingGroovingDiamond GroovingConstruction Considerations

Groove dimensionsDirection of groovingDisposal of slurryProcedures similar to diamond grinding


GroovingGroovingDiamond GroovingEquipment

Head width: 1 to 6 ftLongitudinal blade spacing of 3/4 inchVacuum system employed to collect slurry





GrindingGrindingDiamond GrindingQuality Control

Profile• Pavement roughness• Need acceptance standards

Skid resistance• Standard smooth tire• Improvement may be temporary if aggregate is

susceptible to polishing


GroovingGroovingDiamond GroovingQuality Control

Quality assessed through frictionValues prior to grooving compared with post-grooving valuesDirect measurement of surface texture can also be used


Project Checklist

Preliminary Responsibilities • Document Review • Project Review

Equipment Inspections • Diamond-Grinding Machine• Profilograph or Profiler

Others • Weather Requirements • Traffic Control


Project Checklist

Project Inspection Responsibilities • Alignment • Texture • Residues





Troubleshooting

Construction quality and performance problemsApproach:IdentifyProblem

DetermineCause

IdentifySolution


GrindingGrindingTroubleshooting—GrindingPossible Construction Problems

Lack of horizontal overlap (dogtails)Lack of horizontal overlap (dogtails)

GrindingGrindingTroubleshooting—Grinding What is wrong here?

Unground areas (holidays)Unground areas (holidays)

GrindingGrindingTroubleshooting—Grinding What is wrong here?

Poor vertical match between passesPoor vertical match between passes

GrindingGrindingTroubleshooting—Grinding Possible Construction Problems

Problem:Uneven material removal due to spalledor broken pavementPotential causes?


GrindingGrindingTroubleshooting—Grinding Possible Construction Problems

Problem:Remaining fins do not break easilyPotential causes?


GroovingGroovingTroubleshooting—Grooving Possible Construction Problems

Problem:Unground areas from low spotsPotential causes?


GroovingGroovingTroubleshooting—Grooving Possible Construction Problems

Problem:Non-uniform groove depthsPotential causes?


Troubleshooting Guide – Causes and Solution

“Dogtails”“Holidays”Poor vertical match between passes.The fins that remain after grinding do not quickly break free. Large amounts of slurry on the pavement during grinding.


Troubleshooting Guide – Causes and Solution

Lack of horizontal overlap. Isolated areas with inconsistent groove depth. Inconsistent groove depth near joints. Large amounts of slurry on the pavement during grooving. Light vehicles and motorcycles experience vehicle tracking.





Learning Objectives1. List benefits of diamond grinding and

grooving2. Describe recommended diamond

grinding/grooving dimensions3. Describe recommended construction

procedures4. List important quality control activities5. Describe potential construction and

performance problems6. Identify troubleshooting solutions


Thank You

Questions?


Documents

Chapter 5 Diamond Grinding and Grooving - · PDF fileChapter 5 Diamond Grinding and Grooving ... light cars Chapter 5 – Diamond Grinding and Grooving. GroovingGrooving ... Module