Difference between revisions of "Category:413 Surface Treatments and Preventive Maintenance"

From Engineering_Policy_Guide
Jump to navigation Jump to search
m
 
(20 intermediate revisions by 2 users not shown)
Line 1: Line 1:
==413.1 Materials Inspection==
+
'''What Is Preventive Maintenance?'''
  
===413.1.1 Scope===
+
One of the goals of MoDOT is to "take better care of what we have." Preventive maintenance is the planned strategy of cost-effective treatments to an existing roadway system that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system without substantially increasing structural capacity.
To establish procedures for mix design, inspection and acceptance of materials used in Micro-Surfacing, Scrub Seal, Ultrathin Bonded Wearing Asphalt Surface, Bituminous Fog Sealing, Bituminous Pavement Crack Sealing, Portland Cement Concrete Pavement Joint/Crack Sealing, Bituminous Pavement Crack Filling and Portland Cement Concrete Pavement Crack Filling.  Aggregate for use in surface treatments shall be inspected in accordance with Field Section 1001 in the Materials Manual.  Asphalt Binder for use in surface treatments shall be inspected in accordance with Field Section 1015 in Materials Manual.
 
  
===413.1.2 Procedure===
+
Pavement preventive maintenance is the application of one or more treatments, generally to the surface of a structurally sound roadway. It is performed before the pavement exhibits significant distress and provides for a more uniform performing pavement throughout its design life.
  
====413.1.2.1 Micro-Surfacing====
+
The term "maintenance" can have a different meaning to different people. To some, it is any action intended to keep a facility or its parts functioning as originally designed and constructed. To others it is the act of keeping fixed assets in an acceptable condition, that is, keeping conditions good enough, rather than at initial design levels. Regardless of the definition, maintenance activities are generally categorized as being either "reactive" or "preventive" depending on the intended purpose.
  
'''Mix Design Procedure'''
+
Reactive or corrective maintenance is performed after a deficiency occurs such as a pothole. This is generally little more than a stop-gap approach to keep traffic moving in a safe manner and does not contribute to the long-term performance of the pavement.
  
In order for a micro-surfacing mix formula to be approved, the contractor’s proposed job mix formula (JMF) shall be submitted as required in Standard Specification Sec 413.10.3.  Trial mix samples will not be required unless requested by the Field Office.  If requested, the samples are to be obtained and submitted to the Central Laboratory in accordance with Field Section 1001.  When possible, the JMF and correspondence should be transmitted electronically.  The Materials Field Office e-mail address is MFO.
+
Preventive maintenance is performing surface treatments to protect and preserve the condition of the pavement so that it is either brought back to design level condition or near design level condition.
  
413.2.1.2  District Procedure.  When the District receives a proposed trial mix formula, as required by the Standard Specifications, the mixture properties, components and proportions should be checked to ensure compliance with Specifications and that they are approved for the intended use.  It may be necessary for the District to advise the contractor to make changes in the proposed mixture in order to comply with Department policies.  A QC plan in accordance with Field Section 1001 covering each aggregate fraction should be on file in the District Office or received with the JMF. The target gradations shown on the QC plan and JMF must match.  When the District is satisfied that the proposed mixture is acceptable, a copy of the JMF and the contractor's letter shall be submitted to the Materials Field Office, accompanied by a letter of transmittal with comments, any corrections made and recommendations.  The transmittal letter shall contain the following information:
+
No conceptual study report is necessary for contract leveling course projects, but the core team should give the corridor an elementary examination and document major safety or operational deficiencies. Unless there are very low-cost countermeasures available, the narrow scope of these projects will require that most remedial work be accomplished with maintenance forces or programmed into future projects.
Project information – Job Number, Route, County, Contract Number.
 
Mixture Type
 
Grade and Source of Asphalt Binder
 
Letting Date
 
Proposed Work – Job Location and Length
 
Average Daily Traffic (ADT)
 
Mix Use – Mainline, Shoulders, Outer Roads, etc.
 
Quantity of Mix
 
  
413.2.1.3  Field Office Procedure.  The Materials Field Office is charged with the responsibility of processing the mix formula.  General procedures for processing a micro-surfacing mix formula are as follows:
+
<div id="Selection of Preventive Maintenance Strategy"></div>
 +
'''Selection of Preventive Maintenance Strategy'''
  
a. A letter from a District requesting a mix with a copy of the contractor's JMF and letter is received.
+
The following figure provides assistance in appropriate type of preventive maintenance.
 +
[[Image:413 Selecting Preventive Maintenance Strategy.gif]]
  
b. Contract specifications for the project are checked for necessary items.
+
Surface treatments can also be used to improve non-load associated distresses, roughness, skid resistance, and rutting not associated with unstable asphaltic concrete mixes.
  
 +
To supplement the articles and maintenance planning guidelines in this category there is also a Maintenance Planning Guideline for [[:Category:622 Pavement and Bridge Surface Removal and Texturing#622.1.2 Maintenance Planning Guideline for Coldmilling High Joints|Milling High Joints]] available.
  
c. Grade of asphalt as well as the refinery to be used and the percent asphalt recommended are reviewed.
+
'''Vertical Clearance'''
  
d. Gradations of the aggregates are checked for specification compliance.
+
The minimum vertical clearances used in the design of grade separation structures, as set out in [[:Category:747 Bridge Reports and Layouts#Grades|Bridge Reports and Layouts - Grades]], include an allowance of 6 in. for future resurfacing of the facility under the structure. The preparation of plans for resurfacing projects includes the checking of the vertical clearance at grade separation structures. Reduction of vertical clearance to less than the required minimum for 3R and 4R projects should be provided in the [[131.1 Design Exception Process|design exception information]] including the existing vertical clearance and the thickness of the proposed resurfacing. Upon approval of any design exceptions to minimum vertical clearances, the project manager should notify the District Construction and Materials Engineer so measurement and posting of final vertical clearance is coordinated (See [[:Category:760 General Construction Inspection for Structures#760.4 Vertical Clearance|reporting procedures]] for vertical clearance for more information).
  
e. All calculations on the proposed JMF are checked.
+
For information on erection of vertical clearance signs, see [[903.6 Warning Signs#903.6.22 Low Clearance Sign (W12-2 and W12-2a) (MUTCD Section 2C.27)|Warning Signs - Low Clearance Signs.]]
 
 
f. For verification, a trial may be prepared and submitted to the Laboratory. 
 
 
 
 
 
413.2.2  Scrub Seal.
 
 
 
413.2.2.1  District Procedure.  District procedures are described in Section 413.2.1.2. 
 
 
 
413.2.3  Ultra-Thin Bonded Asphalt Wearing Surface.
 
 
 
413.2.3.1  Mix Design Procedure.  In order for an Ultrathin Bonded Asphalt Wearing Surface mix formula to be approved, the contractor’s proposed job mix formula (JMF) shall be submitted as required in Standard Specification Sec 413.30.2.5.  The time for approval starts when the completed design is delivered to the District.  This time restarts when the District receives information omitted from the original JMF or corrected by the contractor.  Review/verification time includes District and Central Office processing, therefore, each mix should be processed as soon as possible.  Trial mix samples shall be obtained and submitted to the Central Laboratory in accordance with Field Section 1001.  When possible, the JMF and correspondence should be transmitted electronically.  The Materials Field Office e-mail address is MFO.
 
 
 
 
 
413.2.3.2  District Procedure.  District procedures are identical to those shown in Field Section 413.2.1.2.
 
 
 
413.2.3.3  Field Office Procedure.  The Materials Field Office is charged with the responsibility of processing the mix formula.  General procedures for processing an ultra thin bonded asphalt wearing surface mix formula are as follows:
 
 
 
a. A letter from a District requesting a mix with a copy of the contractor's JMF and letter is received.
 
 
 
b. Contract specifications for the project are checked for necessary items.
 
 
 
 
 
c. Grade of asphalt as well as the refinery to be used and the percent asphalt recommended are reviewed.
 
 
 
d. Gradations of the aggregates are checked for specification compliance and compared with the gradations determined by the Laboratory.
 
 
 
e. All calculations on the proposed JMF are checked.
 
 
 
f. For verification, a trial mix is prepared and submitted to the Laboratory.
 
 
 
g. When Central Laboratory tests are completed, the results are compared to the contractor’s and against the specifications.  If the mixes tested cannot be used, the mixture will be rejected.
 
 
 
413.2.4  Bituminous Fog Sealing.
 
 
 
413.2.4.1  District Procedure.  District procedures are described in Field Section 413.2.1.2.
 
 
 
413.2.5  Bituminous Pavement Crack Sealing.
 
 
 
413.2.5.1  District Procedure.  District procedures shall be in accordance with the applicable sections of Field Section 1057.
 
 
 
413.2.6 Portland Cement Concrete Pavement Joint/Crack Sealing.
 
 
 
413.2.6.1  District Procedure.  District procedures shall be in accordance with the applicable sections of Field Section 1057.
 
 
 
413.2.7  Bituminous Pavement Crack Filling.
 
 
 
413.2.7.1  District Procedure.  District procedures shall be in accordance with the applicable sections of Field Sections 1015 and 1057.
 
 
 
413.2.8  Portland Cement Concrete Pavement Crack Filling.
 
 
 
413.2.8.1  District Procedure.  District procedures shall be in accordance with the applicable sections of Field Section 1057.
 
 
 
413.3  REPORT.
 
 
 
413.3.1  Micro-Surfacing.  A letter of transmittal will accompany the approved mixture to the district Operations Engineer with distribution as follows:
 
 
 
Title Copy of Letter ofTransmittal & Approved Mix
 
District Operations Engineer 1
 
Project Operations Clerk 1
 
Resident Engineer 1
 
Field Office File 1
 
 
 
The letter of transmittal and the approved mixture will be sent by electronic mail to the individuals listed above.
 
 
 
A copy of the approved formula accompanied by a letter of transmittal from the District Operations Engineer is to be forwarded to the contractor.
 
 
 
413.3.2  Ultra-Thin Bonded Asphalt Wearing Surface.  Reporting procedures are identical to those shown in Section 413.3.1.
 

Latest revision as of 14:00, 7 April 2017

What Is Preventive Maintenance?

One of the goals of MoDOT is to "take better care of what we have." Preventive maintenance is the planned strategy of cost-effective treatments to an existing roadway system that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system without substantially increasing structural capacity.

Pavement preventive maintenance is the application of one or more treatments, generally to the surface of a structurally sound roadway. It is performed before the pavement exhibits significant distress and provides for a more uniform performing pavement throughout its design life.

The term "maintenance" can have a different meaning to different people. To some, it is any action intended to keep a facility or its parts functioning as originally designed and constructed. To others it is the act of keeping fixed assets in an acceptable condition, that is, keeping conditions good enough, rather than at initial design levels. Regardless of the definition, maintenance activities are generally categorized as being either "reactive" or "preventive" depending on the intended purpose.

Reactive or corrective maintenance is performed after a deficiency occurs such as a pothole. This is generally little more than a stop-gap approach to keep traffic moving in a safe manner and does not contribute to the long-term performance of the pavement.

Preventive maintenance is performing surface treatments to protect and preserve the condition of the pavement so that it is either brought back to design level condition or near design level condition.

No conceptual study report is necessary for contract leveling course projects, but the core team should give the corridor an elementary examination and document major safety or operational deficiencies. Unless there are very low-cost countermeasures available, the narrow scope of these projects will require that most remedial work be accomplished with maintenance forces or programmed into future projects.

Selection of Preventive Maintenance Strategy

The following figure provides assistance in appropriate type of preventive maintenance. 413 Selecting Preventive Maintenance Strategy.gif

Surface treatments can also be used to improve non-load associated distresses, roughness, skid resistance, and rutting not associated with unstable asphaltic concrete mixes.

To supplement the articles and maintenance planning guidelines in this category there is also a Maintenance Planning Guideline for Milling High Joints available.

Vertical Clearance

The minimum vertical clearances used in the design of grade separation structures, as set out in Bridge Reports and Layouts - Grades, include an allowance of 6 in. for future resurfacing of the facility under the structure. The preparation of plans for resurfacing projects includes the checking of the vertical clearance at grade separation structures. Reduction of vertical clearance to less than the required minimum for 3R and 4R projects should be provided in the design exception information including the existing vertical clearance and the thickness of the proposed resurfacing. Upon approval of any design exceptions to minimum vertical clearances, the project manager should notify the District Construction and Materials Engineer so measurement and posting of final vertical clearance is coordinated (See reporting procedures for vertical clearance for more information).

For information on erection of vertical clearance signs, see Warning Signs - Low Clearance Signs.