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Plant Mix Overview. MDT Training Conference Billings, Montana March 1 & 2, 2006. Presented By: Matt Strizich and Danny Hood. Recent Plant Mix Use. Volumetrics Incentives. 1.45 million or 2.85% in 2005 0.48 million or 3.16% so far in 2006 Percentage of total spent on PMS that year.

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Plant mix overview

Plant Mix Overview

MDT Training Conference

Billings, Montana

March 1 & 2, 2006

Presented By:

Matt Strizich and Danny Hood


Recent plant mix use

Recent Plant Mix Use


Volumetrics incentives

Volumetrics Incentives

  • 1.45 million or 2.85% in 2005

  • 0.48 million or 3.16% so far in 2006

  • Percentage of total spent on PMS that year


Ride specification incentives

Ride Specification Incentives

  • 0.39% in 2002

  • 1.51% in 2003

  • 0.9% +/- from 2004-2006

  • Percentage of total spent on PMS that year


Compaction statistics

Compaction Statistics


Compaction issues

Compaction Issues

  • Compaction incentives were 1.04% in 2003 and 1.20% in 2004

  • Dropped to 0.34% in 2005

  • Have a net disincentive of 0.22% so far in 2006


Quick notes

Quick Notes

  • Volumetrics and the Ride Specification are not included on all projects

  • All end-result specifications


Contractors are earning it

Contractors are Earning it!

  • MDT is paying 3-5% of PMS costs in incentives

  • Plant production has been slowed

  • Seeing quality compete with production


Purpose

Purpose

  • Present potential future changes

  • Provide reasoning behind changes

  • Share information from last year

  • Provide the opportunity to ask questions


Topics

Topics

  • Grade S & Grade D Commercial Specification Revisions

  • New ½” Grade S Policy

  • Ride Specification Revisions

  • Compaction Issues in 2005

  • Aggregate Surface Treatment Experiment


Mdt staff

MDT Staff

  • Construction Reviewers

  • Project Staff

  • Internal Audit


Contractors

Contractors

  • Montana Contractors Association (MCA)

  • Non-Uniformity Complaints

  • Claims


Specification change process

Specification Change Process

  • All specification revisions go through the Specification Section

  • Dan Smith and Ryan Antonovich

  • Defined process

  • Standards Committee coming soon


Change process

Change Process

  • Ensures thorough review

  • Reviewed by MDT staff and contractors


Plant mix specifications

Plant Mix Specifications

Grade S and Grade D Commercial


Grades of plant mix

Grade S

Volumetrics

Non-Volumetrics

Grade D Commercial

Tested

Non-Tested

Grades of Plant Mix


Why two versions

Why two versions?

  • Contract administration

  • Quality of the same grades of mix should be equal.

  • Testing and frequency of testing varies


Grade s

Grade S

  • Completely revised mix

  • Grade S has been successful

  • Moved to gyratory compactors

  • Bob Weber and Scott Barnes deserve the credit


Volumetrics

Volumetrics

  • Volumetrics is how MDT administers and controls the plant mix quality

  • True end result specification

    • Successfully encourages contracts to control their operations

    • Want quality to be able to compete with production


Grade d commercial

Grade D Commercial

  • Relatively new specification

  • Always used on “smaller projects”

  • Bill Fogarty leading the committee


Grade b

Grade B

  • Use for bike paths or other features not subject to heavy loading

  • Consider using Grade D or S with chip seals instead


Grade c

Grade C

  • No longer needed

  • Grade D Commercial should be used instead


Change process1

Change Process

  • Plan to review specifications yearly

  • Will continue to see the same issues if they are not identified

  • Anyone can initiate change

  • People doing the work need to identify the issues

    • MDT Project staff

    • Contractors

    • Reviewers


Grade s changes

Grade S Changes

  • Changes are minimal

  • Changes are the same for volumetrics and non-volumetrics versions


Mix designs

Mix Designs

  • 50 Gyration mixes have been eliminated

  • SHRP recommendation for low volume roads

  • Created issues with meeting Hamburg testing requirements


Release agents specification

Release Agents – Specification

  • a)Trucks. Remove trucks from service that leak fluids. When directed, cover each load with canvas or other approved material to protect the mix at Contractor expense. Do not use Diesel fuel as a truck bed release agent. Use a commercially manufactured release agent approved by the Project Manager.


Release agents specification1

Release Agents - Specification

  • b)Rollers. Furnish and use rollers that compact the plant mix to the specified density. Remove rollers that crush the paving aggregates or otherwise damage the plant mix and replace the damaged plant mix at contractor expense.

  • Cleaning Agents. Do not use diesel fuel as a cleaning agent or as a release agent for any paving equipment or operations. Use a commercially manufactured release agent approved by the Project Manager.


  • Release agents justification

    Release Agents - Justification

    • Expands the existing restriction on diesel fuel to all equipment

    • Need to be uniform in our enforcement.

      • Contractors will include additional cost in bids

      • Will eliminate having the issue every time paving starts


    Release agents justification1

    Release Agents - Justification

    • Plant Mix quality

    • Employee safety

    • Environmental concerns


    Plant mix overview

    Tack

    • The cost of SS-1 will be incidental to the cost of Plant Mix Surfacing

    • Includes tack between lifts of paving and for sealing rumble strips

    • Tack is still required in all instances it was previously used


    Plant mix overview

    Tack

    • SS-1 will still be a pay item for some uses

      • Aggregate surface treatment

      • Fog sealing

    • Reasons for change

      • The number of lifts is no longer specified

      • Low cost item


    Grade d commercial1

    Grade D Commercial

    • Mostly Clarifications

    • Extensive revisions last year

      • Previously relied only on compaction to control

      • Not enough control so 5% penalties on specified properties was added


    Grade d commercial2

    Grade D Commercial

    • Wording change

    • Material. Provide Grade D Commercial Plant Mix Bituminous Surfacing with the specified asphalt binder, 1.4% hydrated lime, and meeting Table 701-15A requirements. Use fillers or additives as necessary.


    Grade d commercial3

    Grade D Commercial

    • Clarification

    • c)Sampling. Sample the PGAB meeting subsection 402.03.2 (B). A sample is two one-pint (two 500 ml) containers of PGAB. Sample fillers, hydrated lime, additives, aggregate treatment and tack in accordance with MT-601.


    Grade d commercial4

    Grade D Commercial

    • Revised target air voids

    • Percent Air Voids:

      changed from 3-5 to 2-4

    • Do not want drier mixes

    • Cost of oil is included in the Grade D Commercial bid item


    Grade d commercial5

    Grade D Commercial

    • Reweighing of vehicles is no longer mandatory

    • It should still be done in most cases

    • The Project Manager may randomly designate the re-weighing of loaded vehicles.


    Grade d commercial6

    Grade D Commercial

    • Reduced the “F” factor from 12 to 6

    • a)Acceptance. Rescind Subsection 401.03.12 (E) and replace with the following:

      Plant mix surfacing is evaluated for density on a lot-by-lot basis under Subsection105.03.2, except as noted in Subsection 401.03.12(B). Change the “F” factor for the Compaction element in Table 105-2 Table of Price Reduction Factors from 12 to 6 for plant mix furnished under this provision.


    F factor change

    “F” Factor Change

    • Compaction is no longer the only measure for controlling quality

    • Want to be consistent with other mixes

    • Inflated prices due to haul

    • Too much risk for Contractors


    Grade d commercial7

    Grade D Commercial

    • Wording clarification

    • A 5 percent price reduction (15% maximum), in the unit bid price for PMS Grade D Commercial will be applied for each test not meeting the Mix Design Stability, Flow, Percent Air Voids, Asphalt Binder Properties, Gradation, or Asphalt content specified. Price reductions will be assessed on the quantity of material represented by each failing sample. The quantity of material represented by each sample is the total tons of material produced divided by the total number of samples representing the material.


    Grade d commercial8

    Grade D Commercial

    • The quantity of material represented by each sample is the total tons of material produced divided by the total number of samples representing the material.

    • Changed to help keep administration uniform

    • Fairer to the contractor


    Grade d commercial non tested

    Grade D Commercial – Non Tested

    • Many of the same changes as the tested version

    • Price reductions are only assessed for obviously defective material

    • Added the following: Provide the Project Manager density testing results upon request.


    Contract administration tied projects

    Contract Administration – Tied Projects

    • Issue has been identified

    • Materials working with construction to develop guidance


    Grade s policy

    ½” Grade S Policy


    Plant mix overview

    Why?

    • Compaction Concerns

    • Reduced lift thicknesses

    • Lower overall cost


    October 2003 policy

    October 2003 Policy

    • ½” Required for all lifts less than 60 mm

    • Introduced in response to Grade S compaction concerns

    • Followed SHRP recommendations


    Revised policy april 2005

    Revised Policy – April 2005

    • Limited use of ½” Grade S to low volume roads

    • Reduced the overall use.


    January 2006 revision

    January 2006 Revision

    • Construction Memo

    • Requires the use of ¾” PMS whenever 0.15 ft or greater is required

    • Requires ½” Grade S only be used for overlays

    • Allows reduced overlay depths if ½” is used


    Additional requirements

    Additional Requirements

    • ½” Grade S can only be used if:

      • Ave. Rut = 0.20 inches or less

      • Ave Ride = 80 in/mile or less

      • An isolation lift is required

      • Surfacing Design must approve


    Implementation

    Implementation

    • Surfacing Design will review existing design projects and make recommendations

    • Projects will not be changed from ¾” to ½” Grade S

    • Change orders will be considered – Should not be “no cost”


    Facts

    ½” Gr. S is more difficult to compact

    ½” Gr. S is more expensive

    ½” Gr. S is equal to or better than ¾” structurally

    ½” Facts


    Ride specification revisions

    Ride Specification Revisions


    Meeting agenda

    Meeting Agenda

    • Introduction

    • Project Background

    • Draft Revised Ride Specification

    • Discussion of Pay Adjustment Factors


    Project purpose

    Project Purpose

    • Review Current Specification

    • Compare with Current Literature

    • Compare with State-of-Practice

    • End Products


    Why is pavement roughness important

    Why Is Pavement Roughness Important?

    • Ride Quality

    • Impacts on Vehicle Maintenance


    Why is pavement roughness important1

    Why Is Pavement Roughness Important?

    • User Cost

      • WesTrack Experiment

    $

    Approx. 10% Drop in IRI

    4.5% Increase in Fuel Efficiency

    Savings of 10,257 gal of fuel

    per 1,000,000 veh miles


    Project background

    Project Background

    • Montana Residents Survey in 1998

      • Attention & resources in the following order:

        • Winter maintenance

        • Surface smoothness

        • Highway striping, debris removal, highway signage, winter roadway information, roadway maintenance, rest stop maintenance

        • Etc.


    Revised documents

    Revised Documents

    • Profiler Operations Manual (POM)

      • Comprehensive

    • MT-422 Document

      • Summary of POM

    • QC/QA Plan

      • Emphasis on field activities

    • Draft Revised Ride Specification


    Profiler operations manual pom

    Profiler Operations Manual (POM)

    • Calibration of Equipment

      • Full Calibration Check of Laser Sensors

      • Calibration of Accelerometers

      • Bounce Test Profiling System

      • Calibration of DMI


    Full calibration check of laser sensors

    Full Calibration Check of Laser Sensors

    • Calibrated and sealed by Manufacturer


    Courtesy testing

    Courtesy Testing

    • At least 7 calendar day notice to EPM

    • MDT will provide once per project

      • Not less than 2 and not more than 3 miles of continuous pavement

    • Contractor interprets results


    Surface smoothness

    Surface Smoothness

    • All mainline travel lanes including climbing lanes, passing lanes and ramps that are 0.2 miles or longer

    • Bridge decks included only if paved as part of project


    Surface smoothness1

    Surface Smoothness

    • Not evaluated

      • Climbing and passing lanes less than 0.2 miles

      • Turning lanes

      • Acceleration and deceleration lanes

      • Shoulders and gore areas

      • Road approaches


    Surface smoothness2

    Surface Smoothness

    • Not evaluated

      • Horizontal curves 900 feet or less in centerline radius

      • Pavement within 50 feet of bridge decks (only for bridges not paved as part of project)

      • Pavement within 50 feet of approach slabs and terminal paving points of project


    Profiling test section

    Profiling Test Section

    • Procedures

    • Minimum of Two Runs

    Beginning of Project (BOP)

    End of Project (EOP)

    Exclude Area

    (e.g., Bridge)

    With F5 Key

    Start of Data Collection

    With F3 Key

    End of Data Collection

    With F3 Key

    Approx. 500 ft.

    Approx. 500 ft.


    Quality control report

    Quality Control Report

    Acceptability:

    • For each interval, the average IRI for each run is within ± 5.7% of the mean IRI for both runs

    • If a run has an interval that is outside the acceptable limit, additional runs (up to three) should be made on that lane


    Quality control report1

    Quality Control Report

    Meets Criteria So Use Run 1…for Roughness Report


    Surface profile

    Surface Profile

    • Correct surface profile defects that fail bump criteria

      • 0.40 inches in a distance of 25 feet

    • Correct surface profile defects

      • Milling and filling

      • Diamond grinding


    Bump report

    Bump Report

    • Considered Other Methodologies

      • Profilograph Simulation,

      • Bumpfinder and Grinding Simulation

      • Localized Roughness (TEX-1001-S) Method

    • Current System is Satisfactory


    Bump report1

    Bump Report

    • Bump Report for only first error free profile run in each lane is presented to EPM

    • Defect locations should be physically verified


    File naming convention

    File Naming Convention

    • 7 Characters

      • 1 to 4 is Control Number

      • 5 to 6 is Direction

      • 7 is Lane

    • Example

    1022NBT: Control Number 1022, northbound direction, travel lane


    File directory

    File Directory

    • Two Conventions

      • By Control Number

      • By Date

    D:\1022

    D:\15JUL05


    Current ride specification

    Current Ride Specification


    Data set

    Data Set


    Plant mix overview

    Avg MDT Class I

    Avg MDT Class II

    Avg MDT Class III

    Avg MDT Class IV

    100

    90

    Class IV Target

    80

    Class III Target

    Post-Pave IRI (in/mi)

    70

    60

    Class II Target

    50

    Class I Target

    40

    40

    50

    60

    70

    80

    90

    100

    Post-Pave IRI (in/mi)


    Category 1

    Category 1

    • Target IRI set at 50 to 55 in/mi

    • Project with two or more opportunities to improve the ride

    • Single lift overlays with pre-pave IRI < 110 in/mile

    • Maximum post-pave IRI should not be greater than 90 in/mi


    Category 2

    Category 2

    • Target IRI set at 55 to 60 in/mi

    • Single lift overlays with pre-pave IRI value ³ 110 in/mi and < 190 in/mi

    • Maximum post-pave IRI should not be greater than 95 in/mi


    High pre pave iri roadways

    High Pre-Pave IRI Roadways

    • Exception for roadways with pre-pave IRI >190 in/mi

      • Treat as Category 1

        • 2 or more opportunities

      • Other

        • Budget, functionality, etc.

        • Specify a maximum post-pave IRI NOT be more than 50% of pre-pave IRI


    Opportunities

    Opportunities

    • Placing a gravel base or surfacing course

    • Placing plant mix bituminous base

    • Placing cement treated base

    • Placing pulverized plant mix surfacing

    • Milling

    • Cold recycling (milling and laydown)

    • Each full 0.15 ft increment of new plant mix surfacing


    Data set1

    Data Set


    Plant mix overview

    Avg MDT Class I

    Avg MDT Class II

    Avg MDT Class III

    Avg MDT Class IV

    100

    90

    Class IV Target

    80

    Class III Target

    Post-Pave IRI (in/mi)

    70

    Category 2 Target

    60

    Class II Target

    Category 1 Target

    50

    Class I Target

    40

    40

    50

    60

    70

    80

    90

    100

    Post-Pave IRI (in/mi)


    Plant mix overview

    65

    Avg Category 1

    Avg Category 2

    60

    Category 2 Target

    55

    Category 1 Target

    Post-Pave IRI (in/mi)

    50

    45

    40

    40

    45

    50

    55

    60

    65

    Post-Pave IRI (in/mi)


    Current pay adjustment factor

    Current Pay Adjustment Factor


    Pay adjustment factor category 1

    Pay Adjustment Factor Category 1


    Pay adjustment factor category 2

    Pay Adjustment Factor Category 2


    Testing acceptance

    Testing & Acceptance

    • Prior to seal and cover

    • Performed with 3 working days of completion

    • Contractor must ensure entire finished lane width can be tested and not impeded

    • Test results within 2 working days


    Economic comparison

    Economic Comparison

    • Compared current classification pay versus category pay

    • Evaluated a total of 53 lanes

      • Category 1 would have 47 lanes

      • Category 2 would have 6 lanes


    Total for category 1

    Total for Category 1


    Total for category 2

    Total for Category 2


    Total difference

    Total Difference


    Incentive for category 1

    Incentive for Category 1


    Incentive for category 2

    Incentive for Category 2


    Incentive difference

    Incentive Difference


    Disincentive for category 1

    Disincentive for Category 1


    Disincentive difference

    Disincentive Difference


    Economic impact example

    Economic Impact Example


    Economic comparison1

    Economic Comparison

    • Incentive

      • Payment will be similar to current system

    • Disincentive

      • Penalty will be more rigorous than current system


    Why is pavement roughness important2

    Why Is Pavement Roughness Important?

    • Ride Quality

    • Impacts on Vehicle Maintenance

    • User Cost

    • Montana Residents

    • FHWA Performance Goals

    • National Trends


    Concluding remarks

    Concluding Remarks

    • Held a seminar for contractors

    • Complete Final Report

      • Address Comments

    • Finalize MDT Ride Specification Document

    • First training session – Spring 2006

    • Implementation – June 2006


    Questions

    Questions

    Draft Revised Ride Specification


    Compaction issues 2005

    Compaction Issues – 2005


    What s the problem

    What’s the problem?

    • Extensive problems encountered during 2005

    • Did not appear to be one specific problem

    • Conditions varied between jobs


    Glendive area projects

    Glendive Area Projects


    Potential contributing factors

    Potential Contributing Factors

    • Binder problems

    • ½” PMS

    • Aggregate Surface Treatment

    • Aggregate Surfacing

    • Weather

    • Contractor Operations


    Questions1

    Questions?

    Compaction Issues – 2005


    Aggregate surface treatment

    Aggregate Surface Treatment

    Proposed Experimental Project


    What s wrong with mc 70

    What’s wrong with MC-70

    • High Volatile Organic Compounds or VOC’s

    • Past “prime” failures


    Purpose of surface treatment

    Purpose of Surface Treatment

    • Dust abatement

    • Surface preservation

    • Seal

    • Plant mix compaction aid


    Current practice

    Magnesium Chloride

    SS-1 or CSS-1

    Current Practice


    Advantages

    Advantages

    • Relatively inexpensive

    • Effective for dust abatement

    • Helps preserve the section in most cases

    • Assists with compaction in most cases


    Disadvantages

    Disadvantages

    • Affinity for water

    • Needs “fines” and PI in the gravel for optimum performance

    • Corrosion concerns


    New specification

    New Specification

    • Currently working on writing

    • Intend to allow more flexibility

    • Possibly allow alternate products


    Experimental project s

    Experimental Project(s)

    • Trying alternate emulsified asphalt products

    • Pugmilling SS-1 into the top lift of aggregate surfacing

    • Control sections


    Objectives

    Objectives

    • Try on 2 or 3 projects early in the season

    • Evaluate the constructability immediately

    • If successful, implement as soon as possible


    Questions2

    Questions?

    Aggregate Surface Treatments


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