Presentation is loading. Please wait.

Presentation is loading. Please wait.

Plant Mix Overview MDT Training Conference Billings, Montana March 1 & 2, 2006 Presented By: Matt Strizich and Danny Hood.

Similar presentations


Presentation on theme: "Plant Mix Overview MDT Training Conference Billings, Montana March 1 & 2, 2006 Presented By: Matt Strizich and Danny Hood."— Presentation transcript:

1 Plant Mix Overview MDT Training Conference Billings, Montana March 1 & 2, 2006 Presented By: Matt Strizich and Danny Hood

2 Recent Plant Mix Use

3 Volumetrics Incentives 1.45 million or 2.85% in million or 3.16% so far in 2006 Percentage of total spent on PMS that year

4 Ride Specification Incentives 0.39% in % in % +/- from Percentage of total spent on PMS that year

5 Compaction Statistics

6 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

7 Quick Notes Volumetrics and the Ride Specification are not included on all projects All end-result specifications

8 Contractors are Earning it! MDT is paying 3-5% of PMS costs in incentives Plant production has been slowed Seeing quality compete with production

9 Purpose Present potential future changes Provide reasoning behind changes Share information from last year Provide the opportunity to ask questions

10 Topics Grade S & Grade D Commercial Specification Revisions New ½” Grade S Policy Ride Specification Revisions Compaction Issues in 2005 Aggregate Surface Treatment Experiment

11 MDT Staff Construction Reviewers Project Staff Internal Audit

12 Contractors Montana Contractors Association (MCA) Non-Uniformity Complaints Claims

13 Specification Change Process All specification revisions go through the Specification Section Dan Smith and Ryan Antonovich Defined process Standards Committee coming soon

14 Change Process Ensures thorough review Reviewed by MDT staff and contractors

15 Plant Mix Specifications Grade S and Grade D Commercial

16 Grades of Plant Mix Grade S –Volumetrics –Non- Volumetrics Grade D Commercial –Tested –Non-Tested

17 Why two versions? Contract administration Quality of the same grades of mix should be equal. Testing and frequency of testing varies

18 Grade S Completely revised mix Grade S has been successful Moved to gyratory compactors Bob Weber and Scott Barnes deserve the credit

19 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

20 Grade D Commercial Relatively new specification Always used on “smaller projects” Bill Fogarty leading the committee

21 Grade B Use for bike paths or other features not subject to heavy loading Consider using Grade D or S with chip seals instead

22 Grade C No longer needed Grade D Commercial should be used instead

23 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

24 Grade S Changes Changes are minimal Changes are the same for volumetrics and non- volumetrics versions

25 Mix Designs 50 Gyration mixes have been eliminated SHRP recommendation for low volume roads Created issues with meeting Hamburg testing requirements

26 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.

27 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.

28 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

29 Release Agents - Justification Plant Mix quality Employee safety Environmental concerns

30 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

31 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

32 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

33 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 A requirements. Use fillers or additives as necessary.

34 Grade D Commercial Clarification c)Sampling. Sample the PGAB meeting subsection (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.

35 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

36 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.

37 Grade D Commercial Reduced the “F” factor from 12 to 6 a) Acceptance. Rescind Subsection (E) and replace with the following: Plant mix surfacing is evaluated for density on a lot-by-lot basis under Subsection , except as noted in Subsection (B). Change the “F” factor for the Compaction element in Table Table of Price Reduction Factors from 12 to 6 for plant mix furnished under this provision.

38 “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

39 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.

40 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

41 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.

42 Contract Administration – Tied Projects Issue has been identified Materials working with construction to develop guidance

43 ½” Grade S Policy

44 Why? Compaction Concerns Reduced lift thicknesses Lower overall cost

45 October 2003 Policy ½” Required for all lifts less than 60 mm Introduced in response to Grade S compaction concerns Followed SHRP recommendations

46 Revised Policy – April 2005 Limited use of ½” Grade S to low volume roads Reduced the overall use.

47 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

48 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

49 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”

50 ½” 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

51 Ride Specification Revisions

52 Meeting Agenda Introduction Project Background Draft Revised Ride Specification Discussion of Pay Adjustment Factors

53 Project Purpose Review Current Specification Compare with Current Literature Compare with State-of- Practice End Products

54 Why Is Pavement Roughness Important? Ride Quality Impacts on Vehicle Maintenance

55 Why Is Pavement Roughness Important? User Cost –WesTrack Experiment 4.5% Increase in Fuel Efficiency Savings of 10,257 gal of fuel per 1,000,000 veh miles Approx. 10% Drop in IRI $

56 Project Background Montana Residents Survey in 1998 –Attention & resources in the following order: Winter maintenance Surface smoothness Surface smoothness Highway striping, debris removal, highway signage, winter roadway information, roadway maintenance, rest stop maintenance Etc.

57 Revised Documents Profiler Operations Manual (POM) –Comprehensive MT-422 Document –Summary of POM QC/QA Plan –Emphasis on field activities Draft Revised Ride Specification

58 Profiler Operations Manual (POM) Calibration of Equipment 1.Full Calibration Check of Laser Sensors 2.Calibration of Accelerometers 3.Bounce Test Profiling System 4.Calibration of DMI

59 Full Calibration Check of Laser Sensors Calibrated and sealed by Manufacturer

60 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

61 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

62 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

63 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

64 Profiling Test Section Procedures Minimum of Two Runs Start of Data Collection With F3 Key End of Data Collection With F3 Key Beginning of Project (BOP) End of Project (EOP) Exclude Area (e.g., Bridge) With F5 Key Approx. 500 ft.

65 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

66 Quality Control Report IntervalRun 1Run 2Mean Avg -5.7% Avg +5.7% Does Run 1 Meet Criteria? Does Run 2 Meet Criteria? okay okay okay okay okay okay okay Meets Criteria So Use Run 1…for Roughness Report

67 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

68 Bump Report Considered Other Methodologies –Profilograph Simulation, –Bumpfinder and Grinding Simulation –Localized Roughness (TEX S) Method Current System is Satisfactory

69 Bump Report Bump Report for only first error free profile run in each lane is presented to EPM Defect locations should be physically verified

70 Expectations MDT profiles finished surface 2 times –One run is “the” run –Second run is for quality control After QC activities and acceptance –Operator delivers IRI Report and Bump Report to EPM –Potential defects will be physically examined

71 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

72 File Directory Two Conventions –By Control Number –By Date D:\1022 D:\15JUL05 D:\1022 D:\15JUL05

73 Current Ride Specification Class Target (in/mi) Other Criteria I or more opportunities Pre-Pave IRI < 140 in/mi 2 Opportunities Pre-Pave IRI <90 in/mi Single Lift Overlay II55-75 Pre-Pave IRI  140 in/mi 2 Opportunities Pre-Pave IRI >90 in/mi and <140 in/mi Single Opportunity III56-80 Pre-Pave IRI  140 in/mi and <190 in/mi Single Opportunity IV61-90 Pre-Pave IRI >190 in/mi Single Opportunity

74 Data Set ClassCount Post-Pave IRI Avg (in/mi) Min IRI (in/mi) Maxi IRI (in/mi) Std Dev (in/mi) I II III IV

75 Post-Pave IRI (in/mi) Avg MDT Class I Avg MDT Class II Avg MDT Class III Avg MDT Class IV Class I Target Class II Target Class III Target Class IV Target

76 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

77 Category 2 Target IRI set at 55 to 60 in/mi Single lift overlays with pre- pave IRI value  110 in/mi and < 190 in/mi Maximum post-pave IRI should not be greater than 95 in/mi

78 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

79 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

80 Data Set ClassCount Post-Pave IRI Avg (in/mi) Min IRI (in/mi) Maxi IRI (in/mi) Std Dev (in/mi) I II III IV Cate gory Count Post-Pave IRI Avg (in/mi) Min IRI (in/mi) Maxi IRI (in/mi) Std Dev (in/mi)

81 Post-Pave IRI (in/mi) Class I Target Class II Target Class III Target Class IV Target Category 1 Target Category 2 Target Avg MDT Class I Avg MDT Class II Avg MDT Class III Avg MDT Class IV

82 Post-Pave IRI (in/mi) Avg Category 1 Avg Category 2 Category 1 Target Category 2 Target

83 Current Pay Adjustment Factor ClassActual IRI (in/mi)Pay Factor I < > II < > III < > IV < >900.90

84 Pay Adjustment Factor Category 1 IRI (in/mi)Pay Adjustment Factor < – 17/1000 * IRI 50 < IRI < – 3/200 * IRI 75 < IRI < > 90 Corrective Action Required (Initially Assumed as a Zero Pay)

85 Pay Adjustment Factor Category 2 IRI (in/mi)Pay Adjustment Factor < – 1/50 * IRI 55 < IRI < – 1/175 * IRI > 95 Corrective Action Required (Initially Assumed as a Zero Pay)

86

87

88 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

89 Economic Comparison classification categoryCompared current classification pay versus category pay Evaluated a total of 53 lanes –Category 1 would have 47 lanes –Category 2 would have 6 lanes

90 Total for Category 1

91 Total for Category 2

92 Total Difference Category Current System New System  % of Current System 1 $307,684$179,083$(128,601)58% 2 $43,120$22,389$(20,731)52%

93 Incentive for Category 1

94 Incentive for Category 2

95 Incentive Difference Category Current System New System  % of Current System 1 $362,072$301,494$(60,578)83% 2 $43,120$22,389$(20,731)52%

96 Disincentive for Category 1

97 Disincentive Difference Category Current System New System  % of Current System 1 $(54,388)$(122,411)$(68,022)225%

98 Economic Impact Example Control Number Direction Current Class Current Pay ($) Category New Pay ($) Post-Pave IRI (in/mi) 2945 EBI $ 8,4071 $ 9, WBI $ 6,4091$ 6, NBII $ 8,0962$ 4, SBII $ 7,5692$ 3,482 47

99 Economic Comparison Incentive –Payment will be similar to current system Disincentive –Penalty will be more rigorous than current system

100 Why Is Pavement Roughness Important? Ride Quality Impacts on Vehicle Maintenance User Cost Montana Residents FHWA Performance Goals National Trends

101 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

102 Questions Draft Revised Ride Specification

103 Compaction Issues – 2005

104 What’s the problem? Extensive problems encountered during 2005 Did not appear to be one specific problem Conditions varied between jobs

105 Glendive Area Projects

106 Potential Contributing Factors Binder problems ½” PMS Aggregate Surface Treatment Aggregate Surfacing Weather Contractor Operations

107 Questions? Compaction Issues – 2005

108 Aggregate Surface Treatment Proposed Experimental Project

109 What’s wrong with MC-70 High Volatile Organic Compounds or VOC’s Past “prime” failures

110 Purpose of Surface Treatment Dust abatement Surface preservation Seal Plant mix compaction aid

111 Current Practice Magnesium Chloride SS-1 or CSS-1

112 Advantages Relatively inexpensive Effective for dust abatement Helps preserve the section in most cases Assists with compaction in most cases

113 Disadvantages Affinity for water Needs “fines” and PI in the gravel for optimum performance Corrosion concerns

114 New Specification Currently working on writing Intend to allow more flexibility Possibly allow alternate products

115 Experimental Project(s) Trying alternate emulsified asphalt products Pugmilling SS-1 into the top lift of aggregate surfacing Control sections

116 Objectives Try on 2 or 3 projects early in the season Evaluate the constructability immediately If successful, implement as soon as possible

117 Questions? Aggregate Surface Treatments


Download ppt "Plant Mix Overview MDT Training Conference Billings, Montana March 1 & 2, 2006 Presented By: Matt Strizich and Danny Hood."

Similar presentations


Ads by Google