National Academies Press: OpenBook

Performance-Based Pavement Warranty Practices (2020)

Chapter: Appendix G - West Virginia DOH Warranty Information

« Previous: Appendix F - Pennsylvania DOT Warranty Information
Page 189
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 189
Page 190
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 190
Page 191
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 191
Page 192
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 192
Page 193
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 193
Page 194
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 194
Page 195
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 195
Page 196
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 196
Page 197
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 197
Page 198
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 198
Page 199
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 199
Page 200
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 200
Page 201
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 201
Page 202
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 202
Page 203
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 203
Page 204
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 204
Page 205
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 205
Page 206
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 206
Page 207
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 207
Page 208
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 208
Page 209
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 209
Page 210
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 210
Page 211
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 211
Page 212
Suggested Citation:"Appendix G - West Virginia DOH Warranty Information." National Academies of Sciences, Engineering, and Medicine. 2020. Performance-Based Pavement Warranty Practices. Washington, DC: The National Academies Press. doi: 10.17226/25870.
×
Page 212

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

A P P E N D I X G West Virginia DOH Warranty Information G-1 Section 102 Bidding Requirements and Conditions 102.5.1-Mandatory Proprietary Meetings: This project shall utilize Proprietary Meetings between the Contractor and Division Personnel. The purpose of the Proprietary Meeting is to give each potential bidder an opportunity to review with the Division the Contractor’s proposed pavement system and / or method of handling the requirements of the long-term pavement performance criteria associated with this Project in a confidential setting. At least two (2) calendar days before the scheduled Mandatory Proprietary Meeting date, the Bidder shall submit electronically the following information below to the Director of Contract Administration Division: a. List of personnel that will be attending the Proprietary meeting and their function. No more than five (5) members may attend such meetings. b. Specific meeting agenda presented in outline format. The meeting agenda must be specific in identifying all topics of the meeting which are intended to be presented and/or discussed. This agenda thoroughly review how the bidder plans to construct and maintain the contract to ensure that all performance criteria is met throughout the life of the contract. It shall include at a minimum the following: i. Detail scope of initial construction work. Include typical sections showing pavement lifts and thicknesses, pavement designs and calculations, or other proposed solution details, including details for bridge transitions and approaches. ii. Detail all Maintenance of Traffic (MOT) for all phases of work proposed. Including but not be limited to: addressing the Division’s Drop Off Guidance Design Directive, details of any proposed barrier systems, and / or channelizing devices. Estimated quantities of such items detailed in tables and phasing using current DOH item numbers should be included (The DOH realizes this is only an estimate and is to only be presented to assist the DOH in understanding the Contractor’s proposal). iii. Detail scope of any proposed maintenance schedule throughout the life of the pavement performance period. iv. The Bidder is advised that the Division may require a West Virginia Licensed Professional Engineer to sign and seal any such documents where the design falls outside of normal Division Directives, Specifications, Material Procedures, Manual on Temporary Traffic Control for Streets and Highways, and documented practices. If necessary the Division will allow two (2) working days to obtain such signatures. c. A list of specific questions to be discussed at the proprietary meeting. d. No electronic recording of any kind will be allowed during the Proprietary Meetings. The Division will notify the Contractor of acceptance of the Contractor’s proposed scope of Work, as defined above, and schedule the Bidders Mandatory Proprietary Meeting time. Any questions or request that cannot be answered during the course of the meeting shall be answered within two (2) working days of the Proprietary Meeting. The Division’s representatives will be at a minimum: 1. Specifications Engineer 2. Applicable Regional Construction Engineer

G-2 Performance-Based Pavement Warranty Practices 5. District Construction Engineer 6. FHWA Representative Additional personnel may be asked to attend based on the agenda presented as outlined above. The Bidder shall prepare a summary of minutes of their Proprietary meeting and within three (3) calendar days of the meeting, by 4:00PM furnish to the minutes in Microsoft Word format for review and concurrence by the WVDOH. Minutes may include, but are not limited to: attendees, accounts of what was said, and agreements reached. The minutes shall be submitted electronically to the Director of Contract Administration Division: Jason M Boyd, PE Director Contract Administration Division Jason.M.Boyd@wv.gov Respondents shall mark the summary minutes “Proprietary and Confidential”. The Division will review the minutes within five (5) working days of receipt. The Division reserves the right to edit and return such meeting minutes to the Bidder to reflect the Division’s understanding of the meeting. Because of the proprietary nature of these meetings, neither the agenda nor the minutes will be subject to disclosure until after the Award of the project. The Division will not respond if meeting minutes are not provided in accordance with the aforementioned time restriction. The Division will not accept nor approve meeting minutes that are not provided in accordance with this section. It should be noted that while discussions in these Proprietary Meetings are intended to be confidential, nothing shall preclude the Division from exercising any rights that it may have under this Proposal, including the right to issue addendums as a result of what is discussed in such meetings. Nothing herein shall be construed to preclude the Division from speaking with any Bidder/Contractor at any time prior to the letting date and the Division expressly reserves all such rights to do so. Section 109.30 Lane Rental 109.30.1-Description: This Project will utilize the Lane Rental concept. The intent of Lane Rental is to provide the road-users in the State of West Virginia with the most overall cost effective combination of traffic disruptions and Contract costs. The Lane Rental assessment rates established in this Contract are intended to minimize traffic disruptions, yet allow the Contractor flexibility in scheduling Contract work. They are intended to be reflective of the relative value of traffic disruptions from lane closures to the traveling public where the lane closure is located on the Project. 109.30.2-Lane Restrictions: The Division will pay a daily Lane Rental charge for lane closures within the project limits up to the Contractors bid quantity. Once the bid quantity is exceeded the Contractor will be charged per day fee for lane closures. This fee will be assessed on a per lane basis for each Calendar Day or portion thereof when traffic in either direction is limited to one lane of travel. Access to all residences and businesses shall be maintained. Lane restrictions will apply to all traffic restrictions utilized for all work performed on this project; work accomplished under moving operations will be chargeable. The Lane Rental charges will be assessed when lane closures are in place, whether or not work is in progress. Unless otherwise approved by the Engineer, the Contractor shall have all lanes of traffic open for Holidays, Holiday Weekends and WVU home football games. Due to the length of the Contract, the Contractor is advised that other dates may require two lanes of traffic to be maintained, and the Contractor will be given a minimum notice of 30 days when such situations arise. In the event construction operations are discontinued due to adverse weather or equipment breakdowns, lane closures shall be removed as quickly as possible. 109.30.3-Basis of Payment: The unit value for Lane Rental established in the proposal for Item 109030-002 will be in Dollars / Day ($/DA) and will be computed by the Division. This number reflects the relative value of traffic disruptions from lane closures to the traveling public and the surrounding area. Lane Rental rates do not apply during initial construction work, but will apply any time during the life of the contract after the Acceptance Date of Initial Construction Work, as defined in SP490. The Lane Rental value entered by the Contractor in the Proposal for Item 109030-002 will be the amount of Days the Contactor anticipates for this work. 3. Pavement Engineer – MCS&T Division 4. District Design Engineer or Project Manager

West Virginia DOH Warranty Information G-3 Rental fee, for any necessary lane closures or restrictions, based on the unit values established in this Contract for Item 109030-002. At the conclusion of the construction project, the Contractor shall receive the balance due for the lane rental items defined below. Lane Closures resulting from Extra Work and Force Account as defined in 104.3 and 109.4 will not accrue Lane Rental charges. In the event that Extra Work is done concurrently with regular Contract work, the lane rental charges will still apply. 109.30.4-Pay Items: ITEM DESCRIPTION UNIT 109030-002 Lane Rental Day (Maintenance) Dollars / Day ($/DA) Section 490 Nine Year Pavement Performance Criteria 490.1-Description: The pavement performance period shall consist of satisfying the performance criteria requirements of the work contained in the appendices. This special provision establishes the common terms and definitions. The pavement performance criteria assure and protect the Division from specific defects found in the pavement. 490.1.1-Definitions: Initial Acceptance Date of Initial Construction Work-The date when the work is completed and is continuously open to traffic. This shall be the date of initial acceptance and constitutes the start date for the performance criteria period. For divided highways, there may be more than one acceptance date of work for a project. Performance Lane(s)-The portion of the pavement considered performance criteria work. Each of the following shall be considered a separate performance lane. • Each individual mainline lane and adjacent shoulder • The sum of all ramp lanes and the associated acceleration/deceleration lanes • The sum of all auxiliary lanes, such as passing lanes and turn lanes Approaches and driveways are not considered. Performance Criteria Work - Work that is guaranteed to meet the performance requirements as defined and calculated in Appendix A, throughout the performance rating period. Maintenance Work - Corrective action taken by the Contractor to bring the performance criteria work into compliance with the performance requirements and calculations detailed in Appendix A. July 12, 2017 490.2-Initial Acceptance: The Division and the Contractor shall jointly review all completed work, or a portion thereof, as determined by the Division. If the Division determines that the work is in compliance with the contract specifications and is continuously open to traffic, then the date of initial acceptance occurs. If the work does not meet contract requirements, the Contractor shall make all necessary corrections, at its expense, prior to initial acceptance. The date on which initial acceptance occurs shall be termed the Initial Acceptance Date of Initial Construction Work and is to be documented in accordance with this special provision. As stated in Section 490.1.1, once the Initial Acceptance date has been determined this shall act as the start date for the performance criteria period. The Division may accept any portion of the work and begin the performance period to accommodate seasonal limitations or staged construction, excluding any area needing corrective work. 490.3-This Section Intentionally Left Blank: 490.4-Rights and Responsibilities of the Division: The Division: • Reserves the right to approve the time, traffic control and methods for performing any work. • Reserves the right to approve the schedule proposed by the Contractor to perform work. • Reserves the right to determine if work performed by the Contractor meets the contract specifications. Once the Contractor has utilized the bid quantity for Item 109030-002, the Contractor will be billed a per lane, Lane

G-4 Performance-Based Pavement Warranty Practices • Reserves the right to perform, or have performed, routine core maintenance activities during the performance period, which this routine core maintenance will not diminish the Contractor’s responsibility under the performance criteria. Core Maintenance activities consist of: Mowing, Snow Removal, Striping, Guardrail Repair, Signing, and Maintaining Ditches and other Drainage Structures. • Reserves the right, if the Contractor is unable, to make immediate emergency repairs to the pavement to prevent an unsafe road condition as determined by the Division. The Division will attempt to notify the Contractor that action shall be required to address an unsafe condition. The Division will record the time and date of the attempts for Contractor notification. However, should the Contractor be unable to comply with this requirement, to the Division’s satisfaction and within the required time frame specified by the Division, the Division will perform, or have performed any emergency repairs deemed necessary. Any such emergency repairs undertaken will not relieve the Contractor from meeting the performance requirements of this Special Provision. Any costs associated with such emergency repairs due to defective work will be paid by the Contractor. • Shall be responsible for monitoring the pavement throughout the performance period and will provide the Contractor any written reports of the surface condition or maintenance activities, or both related to pavement performance. • Shall be responsible for notifying the Contractor, in writing, of any corrective action required to meet the pavement performance requirements. 490.5-Rights and Responsibilities of the Contractor: The Contractor: • Shall ensure that the work will be free of defects as measured by the performance parameters and specified threshold values as defined in Appendix A and as measured and defined in Appendix B. • Shall be responsible for performing all work including, but not limited to, maintaining traffic and restoring all associated pavement features, at the Contractor’s expense. • Shall be responsible for performing all work in accordance with any contract details, established WVDOH policies, or Industrywide Best Management Practices, or combination thereof. Use of repair materials different than the constructed pavement structure may be permitted on a temporary basis and no such temporary repairs shall remain in place at the end of the current rating period. Any deviations from such policies shall be approved by the Engineer and may require a signature and seal of a currently Licensed West Virginia Professional Engineer. • Shall be responsible for performing all temporary or emergency repairs, resulting from being in non- compliance with the pavement performance requirements, using Division approved materials. • Shall notify the Division and submit a written course of action for performing the needed work, ten calendar days prior to commencement of said work, except in the case of emergency repairs as detailed in this special provision. The submittal must propose a schedule for performing the work and the materials and methods to be used. • Shall follow a Division approved temporary traffic control plan when performing work. • Shall pay lane rental fees as stipulated in the Contract, during maintenance work. • Shall complete all work required by this special provision and prior to conclusion of the pavement performance period, or as otherwise agreed to by the Division. 490.6-Evaluation Method: The Division will conduct pavement evaluations in accordance with Appendix A and Appendix B of this section. Evaluation may include use of the Division’s Pavement Management System or field pavement condition reviews, including roughness measurements, or both. This evaluation may be waived in emergency situations. Results of the Division’s pavement evaluation will be handed over to the Contractor within thirty (30) days of August 31. These results will detail any bonus or penalties along with locations for various distress areas that require corrective action. 490.7-Pavement Performance Requirements: Maintenance work will be required as per the requirements and calculations of Appendix A.

West Virginia DOH Warranty Information G-5 If included as part of the Contract, the sole responsibility of the Dispute Resolution Board (DRB) is to provide a decision on disputes between the Division and the Contractor regarding application or fulfillment of the pavement performance requirements. The DRB will be in accordance with Section 105.18. July 12, 2017 The DRB will determine the scope of work and select the party to conduct the investigation. All costs related to the forensic investigation will be shared proportionally between the Contractor and the Division based on the determined cause of the condition. 490.9-Emergency Repairs: If the Division determines that emergency repairs are necessary for public safety, the Division or its agent may take repair action. Prior to emergency repairs, the Division will document the basis for the emergency action, will preserve evidence of the defective condition, and document all materials and methods used for the repair. 490.10-Non-Extension of Contract: This Special Provision shall not be construed as extending or otherwise affecting the claim process and statute of limitation applicable to this Contract. July 12, 2017 Section 490: Appendix A Pavement Performance Nine Year Performance Criteria and Evaluation Preliminary Project Evaluation - In order to help facilitate design of a system that meets the criteria set forth in this contract, the Division may perform the following and make available the results to prospective bidders. • Perform Non-Destructive Testing (NDT) to help delineate pavement layer thickness and to help delineate transitions within the overall pavement structure in the pavement performance section. • Perform field coring of pavement at selected locations based on pavement condition, or at locations where abrupt changes in NDT results may indicate a transition in pavement section, or both. Performance Requirements – Pavement Performance Requirements are set for three different categories: Ride Quality (Section A1), Threshold Limits (Section A2), and Pavement Surface Rating (PSR) (Section A3). The finished road surface shall be evaluated annually during the performance period no later than August 31 of each year; this date shall not be extended for any reason. The Contractor can ask the Division to perform the rating prior to August 31. Contractor’s personnel will be allowed to participate and review the evaluation process. If desired, the contractor may monitor and survey the pavement in addition to the work being performed by this agency. However, any destructive work such as coring or milling shall not be performed without approval by the Engineer and at no additional cost to the Division. Corrections for deficient shoulder conditions based on Threshold Limits (Section A2) are included in performance criteria Work, however no PSR ratings or IRI ratings shall be performed on shoulders and no bonuses or penalties shall be received or collected due to shoulder conditions. The Contractor shall be notified of shoulder areas needing corrective action after each Roadway Evaluation, or in case of emergencies. A1 Ride Quality Shoulder work shall be exempt from ride quality measures. Yearly IRI values shall be in accordance with Special Provision 720, Ride Quality for Pavement Surfaces, for the entire length of the project limits. The yearly IRI values shall be determined by the Division no later than August 31 of each year; this date shall not be extended for any reason. The Contractor can ask the Division to perform the rating prior to August 31. The overall IRI shall meet or exceed the following in Table A1 at the specified age: July 12, 2017 Table A1. IRI Criteria Year IRI Criteria for Bonus Bonus IRI Criteria for Penalty Penalty One <65 0.11% >81 0.22% Two <65 0.11% >81 0.22% Three <65 0.28% >81 0.56% Four <65 0.28% >81 0.56% Five <65 0.44% >81 0.88% Six <65 0.44% >81 0.88% 490.8-Dispute Resolution Board:

G-6 Performance-Based Pavement Warranty Practices Seven <65 0.89% >81 1.78% Eight <65 0.89% >81 1.78% Nine <65 1.56% >81 3.12% As noted above, the subject contract allows for payment bonuses and penalties for IRI. Bonus and Penalty Payments are not cumulative and do not carry over from year to year. A2 Threshold Limits and Corrective Action Each distress in the following sections A2.1 and A2.2 has a threshold level applied to each segment of each performance lane before corrective action (maintenance work) shall be required. Following the annual review, this work shall be completed prior to June 10 of the next calendar year. Each lane mile will be divided into 10 equal 0.1 mile segments starting at the beginning milepost. Threshold limits apply to the entire performance section, and have been established to allow a certain extent of low severity distresses within 0.1 mile segments before corrective action is required. Any extent of medium or high severity distresses observed shall require corrective action. Polished Aggregate will be described for informational purposes to support overall characterization of the road surface. Skid testing will be used to quantify acceptable levels of surface friction. Skid Testing will be conducted yearly and completed by the Division or an independent testing firm. Any skid number less than 35 shall require corrective action. Any corrective action required by DOH for skid numbers 35 or greater shall be paid for in accordance with section 109.4. When corrective action is taken to address thresholds within a pavement segment, all distresses associated with that threshold must be addressed in that 0.1 mi segment and the adjacent lane. If a segment that is adjacent to a partial segment (roadway less than 0.1 mile) is subject to corrective action, that adjacent partial segment shall also receive the same corrective action in both lanes. Similarly, should a partial segment be subject to corrective action, the adjacent full segment shall receive the same corrective action in both lanes. Additionally, if a continuous distress exceeds threshold limits and lies within two or more adjacent segments (full or partial), that shall also require corrective action in both lanes. All corrected sections will be monitored for performance. If distresses are repaired and integrity of repair is maintained, it shall not be counted against threshold limits. Any permanent repairs shall be of equal or better quality material than the original section. The Contractor is advised that any permanent repairs consisting of different material properties than was originally placed shall be done over the entire rating segment. July 12, 2017 Additionally, if a repair extends or lies within two or more adjacent segments (full or partial), the adjacent section shall receive the same repair solution. This restriction does not apply to temporary fixes, such as those placed for emergency purposes or placed to slow deterioration during winter. Shoulders have no threshold limits for low severity distresses; however, medium and high severity distresses shall require corrective action. A2.1 Asphalt Pavement Asphalt Surface Threshold Limits of Low Severity Distresses Distress Type Limit Unit Alligator Cracking 23 LF Block Cracking 76 LF Longitudinal Cracking 76 LF Longitudinal Joint Deterioration 50 LF Lane Edge Cracking/ Deterioration 100 LF Raveling/Weathering 40 LF Patching (Note 1) LF Rutting (Note 2) LF Potholes/Surface Delamination (Note 3) 0 Count Note 1: Patches shall require corrective action if any other distresses are found within them. Note 2: Any individual measurement of ½ inch or greater shall require corrective action.

West Virginia DOH Warranty Information G-7 Note 3: Potholes/Surface Delamination refers to bowl-shaped holes or separation of surface and underlying pavement courses of various sizes within the pavement surface, but with generally a minimum plan dimension of 0.5 ft. Areas with excessive segregation or raveling/weathering or areas exhibiting bleeding/flushing will be subject to measurements of Macrotexture as per MP 401.07.24 Standard Test Method for Measuring Pavement Macrotexture Depth using a Volumetric Technique. These open areas will be monitored throughout the performance period. Should the condition of these distresses continue to deteriorate, further investigation will be required to determine if maintenance work is required. If the average macrotexture test depth in flushed areas is less than or equal to 0.006 inches (0.152mm) then maintenance work is required. A2.2 PCC Pavement PCC Surface Threshold Limits of Low Severity Distresses Distress Type Limit Unit Transverse Joints Spalls (Note 1) 5 Count Blowups 0 Count Longitudinal Cracking 76 LF Longitudinal Joint Spalling 76 LF Lane Edge Spalling 76 LF D Cracking (Note 2) 0 Count Scaling (Note 3) 39 LF Patching (Note 4) LF Popouts 76 LF Note 1: There is no threshold for low severity spalls with no loss of material. Note 2: Should D-Cracking occur, a special evaluation may be conducted and corrective action will be paid for by section 109.4. Note 3: Scaling or map cracking greater than one inch in depth shall require corrective action. Note 4: Partial Depth Repairs with any other distresses in them shall require corrective action. A3 Pavement Surface Rating The Pavement Surface Rating (PSR) will represent the West Virginia Division of Highways (WVDOH) crack and surface distress index for this contract. It uses a 0.0 to 100.0 rating scale: the higher the number, the less overall distress shall be present. Generally, a perfect or newly constructed road has a PSR of 100.0. As the type, amount and severity of the various defects increase, the PSR drops. The pavement distresses that make up the PSR are determined by the Division using the criteria contained in this provision and Appendix B. Each lane mile will be divided into 10 equal 0.1 mile segments starting at the beginning milepost. Initially, the road surface evaluation for determining the (PSR) will be performed at two 0.1 mile (528’) segments within each lane mile by the Division. • One PSR evaluation segment will initially lie between 0.4 and 0.5 miles within that lane mile. • An additional PSR evaluation segment within each mile will be selected randomly by the Engineer. • Partial mile sections at the beginning and end of a contract shall also have segments for determination of PSR identified. • For sections less than 0.6 miles in length, one 0.1 mile segment shall be randomly selected. • For sections 0.6 miles or greater in length, two 0.1 mile segments shall be randomly selected. Once the PSR evaluation segments are identified, the same segments will be used for the remainder of the performance period. If, however, it is suspected that the resulting PSR is not representative of the general overall road surface condition, one or more new segments may be randomly selected for determination of PSR. If corrective action is performed on a PSR evaluation segment, a new segment may be selected for determination of PSR. The overall PSR shall meet or exceed the following in Table A3 at the specified age: Table A3. PSR Criteria Year PSR Criteria for Bonus Bonus PSR Criteria for Disincentive Penalty One 98 0.11% <96 0.22%

G-8 Performance-Based Pavement Warranty Practices Year PSR Criteria for Bonus Bonus PSR Criteria for Disincentive Penalty Two 97 0.11% <95 0.22% Three 96 0.28% <94 0.56% Four 90 0.28% <88 0.56% Five 90 0.44% <88 0.88% Six 90 0.44% <88 0.88% Seven 85 0.89% <80 1.78% Eight 85 0.89% <80 1.78% Nine 85 1.56% <80 3.12% Please note that the subject contract allows for payment bonuses for PSR. Bonus and Penalty Payments are not cumulative and do not carry over from year to year. A3.1 Calculating the Pavement Surface Rating (PSR) A3.1.1 Step One – Categorize and measure all distresses in the roadway Refer to Appendix B for definitions of distress types and severity levels. For bituminous surfaced pavements, the following distress types are measured and recorded for calculation of PSR. Asphalt Distress Severity Levels How to Measure Transverse Cracking Low, Medium, High Count Longitudinal Cracking Low, Medium, High Linear Feet Longitudinal Joint Deterioration Low, Medium, High Linear Feet Lane Edge Cracking Low, Medium, High Linear Feet Block Cracking Low, Medium, High Linear Feet Alligator Cracking Low, Medium, High Linear Feet Rutting Low, High Linear Feet Raveling & Weathering None Linear Feet Patching None Linear Feet For jointed concrete pavements, the following distress types are measured and recorded for calculation of PSR. PCC Distress Severity Levels How to Measure Transverse Joint Spalling Low, Medium, High Count Transverse Joint Faults Low, Medium, High Count Blowups None Count Patching None Linear Feet D-Cracking None Linear Feet Longitudinal Joint Spalling Low, Medium, High Linear Feet Lane Edge Spalling Low, Medium, High Linear Feet Transverse Cracks Low, Medium, High Count Longitudinal Cracks Low, Medium, High Linear Feet Scaling None Linear Feet Popouts None Linear Feet Important details to remember for PCC Pavements: • Count the total number of joints in each 0.1 mile (528’) rating segment. If the segment starts exactly on a joint, do not count the last joint if the segment also ends exactly on a joint.

West Virginia DOH Warranty Information G-9 • Any full depth concrete repairs will add to the number of joints. For example, a full depth repair on a joint will replace the existing joint with two spaced joints, where a full depth repair on a mid-panel crack will simply add two joints. • Partial depth concrete repairs do not add to the number of joints, however, their length will be counted towards patching. A3.1.2 Step Two – Convert the amount of distress to a percent (round to the nearest 0.1%) The amount of each distress type at each severity level must be converted to percent as described below. Bituminous Pavements: For bituminous pavements, the number of transverse cracks, at all severities, shall be converted to percent using the following: Percent Cracks (%) = Number of Cracks x 2.85 (not to exceed 100%) For other distresses, simply divide the length of each defect by the length of the surveyed section, 528’ in most cases, and then multiply the quotient by 100 to get percent. For distresses measured in linear feet, the sum of the length of all levels of severities for that distress type shall not exceed 528 feet. If multiple severities of the same distress type exist in the same linear foot, the higher severity shall be used. Jointed Concrete Pavements: For jointed concrete pavement, as with bituminous pavements, the number of transverse cracks, at all severities, shall be converted to percent using the following: Percent Cracks (%) = Number of Cracks x 2.85 (not to exceed 100%) Count the total number of joints in the segment. Distresses that occur at transverse joints, i.e., transverse joint spalls, transverse joint faults, and blowups, are to be measured by counting the number of affected joints. This count is then divided by the total number of transverse joints to get the percent affected. All other distresses, such as longitudinal cracking, longitudinal joint spalling, and scaling, shall be measured on a length basis. This number is then divided by the total segment length to get percent affected. For distresses measured in linear feet, the sum of the length of all levels of severities for that distress type shall not exceed the segment length. If multiple severities of the same distress type exist in the same linear foot, the higher severity shall be used. A3.1.3 Step Three – Weight Factors Weight Factors are a numerical representation given to the types of roadway distresses at different severity levels. These weight factors are pre-determined by the division and are listed in the table below. Table A3.1.3 – Weight Factors Asphalt Distress Severity Weight Factor Concrete Distress Severity Weight Factor Transverse Cracks Low 0.02 Transverse Cracks Low 0.04 Medium 0.11 Medium 0.1 High 0.2 High 0.21 Edge Cracking Low 0.015 Transverse Joints Spalls Low 0.02 Medium 0.025 Medium 0.075 High 0.08 High 0.15 Alligator Cracking Low 0.14 Transverse Joint Faults Low 0 Medium 0.24 Medium 0.11 High 0.34 High 0.21 Block Cracking Low 0.055 Blowups - 0.25 Medium 0.105 High 0.165 Low 0.02 Low 0.03

G-10 Performance-Based Pavement Warranty Practices Asphalt Distress Severity Weight Factor Concrete Distress Severity Weight Factor Longitudinal Cracking Medium 0.03 Longitudinal Cracking Medium 0.09 High 0.06 High 0.19 Longitudinal Joint Deterioration Low 0.025 Longitudinal Joint Spalling Low 0.02 Medium 0.045 Medium 0.06 High 0.08 High 0.15 Lane Edge Cracking/Deterioration Low 0.01 Lane Edge Spalling Low 0.01 Medium 0.02 Medium 0.05 High 0.04 High 0.15 Raveling/Weathering - 0.04 D Cracking - 0.1 Patching - 0.03 Scaling - 0.02 Rutting Low 0.065 Patching - 0.03 High 0.15 Popouts - 0.035 Note: For Jointed Concrete Pavements, since distress factors are based on 35 joints per segment (15’ slabs), and there can be a varying number of joints and slab lengths, a normalized weight factor needs to be calculated for the distresses that are counted on a joint basis. To do this, multiply the original weight factor by the number of joints divided by 35. Please note this only applies to transverse joint spalls, transverse joint faults, and blowups. A3.1.4 Step Four – Calculate the Individual Weighted Distress Multiply the percent of each distress by the appropriate weight factors. A3.1.5 Step Five – Calculate the Total Weighted Distress (TWD) Sum up all the Individual Weighted Distress to get the Total Weighted Distress. A3.1.6 Step Six – Convert the TWD to PSR Use the TWD in the following formula or Table A3.1.6 to find the PSR of the segment. PSR = 25 [ 1.386−(0.045)( )] Values may need to be interpolated for either column. PSR should be reported to the nearest decimal. Traditional rounding procedures for numbers 5 and above are to be used when determining PSR. Do not use WVDOH rounding procedures. Table A3.1.6 Total Weighted Distress PSR Total Weighted Distress PSR 0.0 100.0 3.4 85.8 0.2 99.1 3.6 85.0 0.4 98.2 3.8 84.3 0.6 97.3 4.0 83.5 0.8 96.4 5.0 79.8 1.0 95.6 6.0 76.3 1.2 94.7 7.0 73.0 1.4 93.9 8.0 69.7 1.6 93.0 9.0 66.7 1.8 92.2 10.0 63.7 2.0 91.4 15.4 50 2.2 90.5 20.4 40 2.4 89.7 26.8 30

West Virginia DOH Warranty Information G-11 2.6 88.9 30.8 25 2.8 88.1 35.8 20 3.0 87.3 42.1 15 3.2 86.6 51.2 10 A3.1.7 Step Seven – Average the PSR for all individual segments within the contract A3.2 Asphalt Pavement Example: One 528’ segment within one lane mile of Hot-Mix Asphalt constructed road was surveyed and found to have the following defects: A3.2.1 Step One – Categorize and measure all distresses in the roadway Distress Type Severity Amount Transverse Cracking Low 20 Cracks Transverse Cracking Medium 5 Cracks Longitudinal Joint Deterioration Medium 528 Linear Feet Block Cracking High 53 Linear Feet A3.2.2 Step Two – Convert the amount of distress to a percent (round to the nearest 0.1%) Distress Type Severity Percent Transverse Cracking Low 20*0.0285 = 57.0% Transverse Cracking Medium 5*0.0285 = 14.3% Longitudinal Joint Deterioration Medium 528/528 = 100% Block Cracking High 53/528 = 10.0% A3.2.3 Step Three – Weight Factors Obtained from Table A3.1.3 A3.2.4 Step Four and Five – Calculate the Individual Weighted Distress and Total Weighted Distress (TWD) Distress Type Severity Weight Factor Percent Individual Weighted Distress Transverse Cracking Low 0.02 X 57.0 1.14 Transverse Cracking Medium 0.11 X 14.3 1.57 Longitudinal Joint Deterioration Medium 0.045 X 100 4.5 Block Cracking High 0.165 X 10.0 1.66 Total Weighted Distress (TWD) 8.86 A3.2.5 Step Six – Convert the TWD to PSR The TWD of 8.86 shall be considered on the left side of Table A3.1.6 and by using the formula: PSR = 25 [ 1.386−(0.045)( )] Using both methods, a TWD of 8.86 yields a PSR of 67.1. The contract contains a total of four travel lanes covering four miles. Therefore, with two segments per lane mile, a total of 32 individual sections will be evaluated. The values for each section are summed and divided by 32, yielding the reported PSR for the entire contract section. A3.2.6 Step Seven – Average the PSR for all individual segments within the contract

G-12 Performance-Based Pavement Warranty Practices A3.3.1 Step One – Categorize and measure all distresses in the roadway Distress Type Severity Amount Transverse Cracking Low 8 Transverse Joint Spalling Medium 13 Joints Longitudinal Joint Spalling Medium 156 Linear Feet Transverse Joint Faults Medium 8 Joints A3.3.2 Step Two – Convert the amount of distress to a percent (round to the nearest 0.1%) Distress Type Severity Percent Transverse Cracking Low 8*0.0285 = 23% Transverse Joint Spalling Medium 13 joints/88 joints = 14.8% Longitudinal Joint Spalling Medium 156/528 = 30% Transverse Joint Faults Medium 8 joints/88 joints = 9.1% A3.3.3 Step Three – Weight Factors Obtained from Table A3.1.3. Calculating the Normalized Weight Factor will be necessary for Transverse Joint Spalling. With a total of 88 transverse joints in the segment and a weight factor of 0.075, ℎ = 0.075 × ( 88 35 ) = 0.19 A3.3.4 Steps Four and Five – Calculate the Individual Weighted Distress, and Total Weighted Distress Distress Type Severity Weight Factor Normalized Weight Factor (if applicable) Percent Individual Weighted Distress Transverse Cracking Low 0.04 - X 23 0.91 Transverse Joint Spalling Medium 0.075 0.19 X 14.8 2.79 Longitudinal Joint Spalling Medium 0.06 - X 30 1.77 Transverse Joint Faults Medium 0.11 - X 9.1 2.51 Total Weighted Distress (TWD) 7.98 A3.3.5 Step Six – Convert the TWD to PSR The TWD of 7.98 shall be considered on the left side of Table A3.1.6 and by using the formula: PSR = 25 [ 1.386−(0.045)( )] Using both methods, a TWD of 5.23 yields a PSR of 69.8. A3.3.6 Step Seven – Average the PSR The contract contains a total of four travel lanes covering four miles. Therefore, with two segments per lane mile, a total of 32 individual sections will be evaluated. The values for each section are summed and divided by 32, yielding the reported PSR for the entire contract section. Section 490: Appendix B Pavement Performance Distress Identification Manual This manual is used to define distresses and their severity levels found in pavements, to be used with roads manually surveyed for the calculation of PSR on 0.10 mile long test sections as part of WVDOT Special Provision Section 490: Nine Year Pavement Performance Criteria. A3.3 PCC Example One 528’ segment within one lane mile of Portland Cement Concrete constructed road was surveyed and found to have the following defects for a 6’ x 6’ panel overlay system:

West Virginia DOH Warranty Information G-13 B1.1 Transverse Cracks – Transverse cracks are any cracks within the travel lane predominantly perpendicular to the pavement centerline. This may include reflection cracking in composite pavements. In the case of full width patching that produces transverse construction joints, evaluate distresses in these joints as transverse cracks using the severity levels described in Longitudinal Joint Deterioration. Rate the entire crack at highest level present for 10% or more of total crack length. Extent is calculated by multiplying amount of cracks at each distress level by 2.85. The sum of all three severities cannot exceed 100%. If this happens, disregard cracks of the lowest severity present until the sum of percentages equals 100%. B1.1.1 Low • unsealed cracks 0 – ¼ inch wide, no blowups, no adjacent random cracking, and no loss of material • sealed cracks with sealant material in good condition, no faulting, no blowups, no adjacent random cracking, and no loss of material B1.1.2 Medium • any crack ¼ – ¾ inch wide, no blowups, no adjacent random cracking, and no loss of material • any crack less than ¾ inch wide with adjacent low severity cracking, no blowups, and no loss of material B1.1.3 High • any crack greater than ¾ inch wide • any crack with adjacent medium or high severity random cracking • any crack with a noticeable blowup • any crack with noticeable loss of material B1.2 Edge Cracking – Edge cracking refers to any crescent shaped or predominantly longitudinal cracks in the travel lane (including the paint stripe) that are within 2 feet of the pavements edge. This can occur only where there is an unpaved shoulder. Edge cracking may include longitudinal reflection cracking in composite pavements. Rate the entire crack at highest level present for 10% or more of total crack length. For each severity, the total length of edge cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. In the event of a one lane road with unpaved shoulders on both sides of the travel lane surveyed, the calculation will remain the same however now there will be the potential for a maximum of 200%. B1.2.1 Low • unsealed cracks 0 – ¼ inch wide and no loss of material • sealed cracks with sealant material in good condition B1.2.2 Medium • any crack ¼ – ¾ inch wide and no loss of material B1.2.3 High • any crack greater than ¾ inch wide • any crack with noticeable loss of material or loose pieces of pavement B1.3. Alligator Cracking – Alligator cracking occurs only in areas subjected to repeated traffic loadings (wheelpaths). The exact location of the wheelpath is based on the inspector’s judgment but will usually occur approximately 1.5 feet from paint stripes and extend about 2.5 feet from that point. Alligator cracks appear as interconnected cracks in early stages and may develop into many sided, sharp angled pieces, usually less than 1 foot in any dimension, characteristically with a chicken wire/alligator pattern. Meandering longitudinal cracking with adjacent random cracking can be considered alligator cracking if it is within the wheelpath. In this case it cannot also be counted as longitudinal cracking. Severity of alligator cracking can change between each linear foot of pavement. Rate cracks at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of alligator cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. If alligator cracking is present in both wheelpaths, consider only the higher severity within each linear foot. For example, if a ten foot section of pavement exhibits low severity alligator cracking in the left wheelpath and high severity alligator cracking in the right wheelpath, only ten feet of high severity alligator cracking shall be recorded. If that same section exhibit low severity alligator cracking in both wheelpaths, only ten feet of low severity alligator cracking shall be recorded. B1. Asphalt Surfaces These distress definitions, severity levels, and calculations are specific to asphalt surfaced roads. This may also include composite pavements (concrete pavements with asphalt overlays).

G-14 Performance-Based Pavement Warranty Practices B1.3.1 Low • an area with only a few connecting cracks and no noticeable loss of material B1.3.2 Medium • an area of interconnecting cracks that forms a complete pattern but no considerable loss of material B1.3.3 High • an area of interconnecting cracks with noticeable loss of material or loose pieces B1.4 Block Cracking – Block cracking is a pattern of cracks that divides the pavement into approximately rectangular pieces greater than 1 foot and less than 10 feet in any dimension. This can occur anywhere within the lane. If a series of cracks is identified as block cracking, it should not also be counted as any other distress. Severity of block cracking can change between each linear foot of pavement. Rate cracks at highest level present for 10% or more of each section within the block cracking pattern. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of block cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B1.4.1 Low • unsealed cracks 0 – ¼ inch wide, no adjacent random cracking, and no loss of material • sealed cracks with sealant material in good condition B1.4.2 Medium • any crack ¼ – ¾ inch wide, no adjacent random cracking, and no loss of material • any crack less than ¾ inch wide with adjacent low severity cracking, and no loss of material B1.4.3 High • any crack greater than ¾ inch wide • any crack with adjacent medium or high severity random cracking • any crack with noticeable loss of material B1.5 Longitudinal Cracking – Longitudinal cracks are any cracks within the travel lane predominantly parallel with the pavement centerline. This may include reflection cracking in composite pavements. If a crack has been identified as longitudinal cracking, it should not be counted as any other distress. Severity of longitudinal cracking can change between each linear foot of pavement. Meandering longitudinal cracking with adjacent random cracking can be considered alligator cracking if it is within the wheelpath. In this case it cannot also be counted as longitudinal cracking. Rate cracks at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of longitudinal cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. If multiple longitudinal cracks are present in any linear foot of the lane, record only the highest severity within each linear foot. B1.5.1 Low • unsealed cracks 0 – ¼ inch wide, no adjacent random cracking, and no loss of material • sealed cracks with sealant material in good condition, no adjacent random cracking, and no loss of material B1.5.2 Medium • any crack ¼ – ¾ inch wide, no adjacent random cracking, and no loss of material • any crack less than ¾ inch wide with adjacent low severity cracking, and no loss of material B1.5.3 High • any crack greater than ¾ inch wide • any crack with adjacent medium or high severity random cracking • any crack with noticeable loss of material B1.6 Longitudinal Joint Deterioration – Longitudinal joint deterioration refers to any distresses affecting the deterioration of longitudinal construction joints found entirely within travel lanes. Any distress occurring exclusively within six inches of a longitudinal joint should be counted only as joint deterioration. Any longitudinal joint located within (or 6 inches from) the paint line separating a lane from a shoulder shall be evaluated with the lane edge cracking distress. Otherwise count deterioration in whichever lane the joint is located. If a longitudinal joint is found within the

West Virginia DOH Warranty Information G-15 divider line between travel lanes, consider that joint a part of the slower (right) lane. Severity of longitudinal joint deterioration can change between each linear foot of pavement. Rate cracks at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of longitudinal joint deterioration measured in linear feet will be divided by 528 and then multiplied by 100 to determine the percent of test section affected. In the unlikely event that multiple longitudinal joints are found within a single lane, percent affected could exceed 100%. B1.6.1 Low • unsealed crack 0 – ¼ inch wide propagating from the joint into the pavement, no adjacent random cracking • minor loss of material on either side of a construction joint and no adjacent random cracking within 6 inches of the joint • any other low severity distress located within 6 inches of a joint B1.6.2 Medium • a crack ¼ – ¾ inch wide propagating from the joint into the pavement, no adjacent random cracking • a crack less than ¾ inch wide propagating from the joint into the pavement, adjacent random cracking less than ¼ inch wide • minor loss of material on either side of a construction joint and adjacent random cracking less than ¼ inch wide • any other medium severity distress located within 6 inches of a joint B1.6.3 High • a crack greater than ¾ inch wide propagating from the joint into the pavement • a crack propagating from the joint into the pavement with adjacent random cracking greater than ¼ inch wide • major loss of material on either side of a construction joint • minor loss of material on either side of a construction joint and adjacent random cracking greater than ¼ inch wide B1.7 Lane Edge Cracking/Deterioration – Lane edge cracking/deterioration refers longitudinal joint deterioration specifically between a travel lane and a paved shoulder. A paved shoulder here is defined by at least two feet of pavement past the paint stripe. Lane edge cracking/deterioration also includes any distress which occurs or stretches into the paint stripe or first 6 inches of lane. All definitions of longitudinal joint deterioration apply to this location. Additionally lane edge cracking will include cracking in the paint stripe which propagates into the pavement and is caused by the paint itself. Severity of lane edge cracking/deterioration can change between each linear foot of pavement. Rate cracks or deterioration at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of lane edge cracking/deterioration measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B1.7.1 Low • unsealed crack 0 – ¼ inch wide propagating from the paint into the pavement, no adjacent random cracking • unsealed crack 0 – ¼ inch wide propagating from the joint into the pavement, no adjacent random cracking • minor loss of material on either side of a construction joint and no adjacent random cracking within 6 inches of the joint • any other low severity distress located within 6 inches of a joint B1.7.2 Medium • a crack ¼ – ¾ inch wide propagating from the paint into the pavement, no adjacent random cracking • a crack less than ¾ inch wide propagating from the paint into the pavement, adjacent random cracking less than ¼ inch wide • a crack ¼ – ¾ inch wide propagating from the joint into the pavement, no adjacent random cracking • a crack less than ¾ inch wide propagating from the joint into the pavement, adjacent random cracking less than ¼ inch wide • minor loss of material on either side of a construction joint and adjacent random cracking less than ¼ inch • wide any other medium severity distress located within 6 inches of a joint

G-16 Performance-Based Pavement Warranty Practices B1.7.3 High • a crack greater than ¾ inch wide propagating from the paint into the pavement • a crack propagating from the paint into the pavement with adjacent random cracking greater than ¼ inch wide • a crack greater than ¾ inch wide propagating from the joint into the pavement • a crack propagating from the joint into the pavement with adjacent random cracking greater than ¼ inch wide • major loss of material on either side of a construction joint • minor loss of material on either side of a construction joint and adjacent random cracki • ng greater than ¼ inch wide B1.8 Raveling/Weathering – Raveling and weathering refer to the wearing of pavement surface characterized by the dislodging of aggregate particles and loss of asphalt binder. It may range from loss of fines and binder between coarse aggregate to very rough and pitted surface with obvious loose aggregate. Raveling/weathering is recorded in linear feet. If any of the pavement within the lane appears to be raveled/weathered then it should be recorded. The total length of raveling/weathering measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B1.9 Patching – Patching refers to any portion of pavement surface that has been replaced or added to after the original construction. This includes full depth repairs. All other distresses found within the patch shall still be recorded. The perimeter of a patch does not get recorded as any type of cracking as long as it is maintained. Patching of any type, width, depth, etc. within the lane is recorded in linear feet. The total length of patching measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B1.10 Rutting – Rutting refers to pavement surface depression due to repeated loading, within the wheelpath, and occurring in the longitudinal direction. Rutting severity is based on the average rut depth of 5 measurements in each wheelpath. These measurements should be taken approximately at the 64th, 164th, 264th, 364th, and 464th foot of the test section. These rut measurements will be taken using a 5 foot long straight edge, placed perpendicular to the pavement centerline. Rut depth is measured at the point of greatest distance from the bottom of the straightedge to the pavement surface. Measurements must be accurate to the closest 1/16th inch. If the average rut depth for the five measurements in either wheelpath qualify for a severity, then that entire test section is recorded at that severity. Also if both wheelpaths qualify, the higher severity shall be recorded. If the average rut depth qualifies for a severity, then 100% of that section is recorded at that severity. B1.10.1 Low • average rut depth ¼ – less than ½ inch B1.10.2 High • average rut depth greater than or equal to ½ inch B2.Concrete Surfaces These distress definitions, severity levels, and calculations are specific to all concrete surfaced roads. This may include jointed reinforced concrete pavements, jointed plain concrete pavements, and continuously reinforced concrete pavements. Surveys on pavements with concrete surfaces require an input for number of joints within the 1/10th mile segment as some extent calculations are dependent on this. If the segment starts exactly on a joint, do not count the last joint if the segment also ends exactly on a joint. B2.1 Transverse Cracks – Transverse cracks are cracks predominantly perpendicular to the pavement centerline and propagate through the width of the slab. This may count a linear crack that separates a corner of a slab. This is sometimes referred to as a corner break but shall be recorded as a transverse crack if it is predominantly perpendicular to the pavement centerline. Rate entire crack at highest level present for 10% or more of total crack length. Extent is calculated by multiplying amount of cracks at each distress level by 2.85. The sum of all three severities cannot exceed 100%. If this happens, disregard cracks of the lowest severity present until the sum of percentages equals 100%. B2.1.1 Low • unsealed cracks less than 1/8 inch wide, no faulting, no spalling sealed cracks with sealant material in good condition, no faulting, no spalling

West Virginia DOH Warranty Information G-17 B2.1.2 Medium • any crack 1/8 to less than ¼ inch wide, no faulting, no spalling • any crack less than ¼ inch wide with faulting up to 3/8 inch • any crack less than ¼ inch wide with spalling up to 3 inches wide • any crack that would otherwise be considered Low Severity but is accompanied by additional Low Severity cracks that fragment the slab B2.1.3 High • any crack greater than ¼ inch wide • any crack with greater than 3/8 inch faulting • any crack with greater than 3 inch wide spalling • any crack that would otherwise be considered Medium Severity but is accompanied by additional Low or Medium Severity cracks that fragment the slab B2.2 Transverse Joint Spalls – Transverse joint spalling refers to cracking, breaking, chipping, or fraying of slab edges at transverse joints. Spalling includes any cracking within 1 foot of the face of the joint. Spalling is counted on a per joint basis so it does not matter if the spalling occurs on the leave or approach slab. Spall width is based on the distance from the face of the joint to the crack or end of displaced material on either side of the joint. If there is no loss of material but cracking is still present, the spall width is zero but it is still considered spalled at low severity. Rate a joints spalling as the highest severity present for at least 10% of the joint length. Spalling is recorded on a per joint basis so the entire joint is considered spalled at that severity. Record the number of transverse joints with spalling at each severity level. Divide the amount of affected joints at each severity level by the total number of joints in the segment. Multiply by 100 to determine the extent of segment affected. B2.2.1 Low • spall widths up to 2 inches • joints with low severity cracking in crescent shaped patterns or parallel to the joint within 1 foot of the joint B2.2.2 Medium • spall widths 2 – 4 inches B2.2.3 High • spall widths greater than 4 inches B2.3 Transverse Joint Faults – Transverse joint faulting refers to the difference in elevation across a transverse joint. This can be an increase or decrease in elevation from the leave to the approach slab. It is recorded on a per joint basis. Rate a joints faulting as the highest severity present for at least 10% of the joint length. Faulting is recorded on a per joint basis so the entire joint is considered faulted at that severity. Record the number of transverse joints with faulting at each severity level. Divide the amount of affected joints at each severity level by the total number of joints in the segment. Multiply by 100 to determine the extent of segment affected. B2.3.1 Low • measurable faulting to a maximum of 1/8 inch B2.3.2 Medium • faulting greater than 1/8th inch but less than ½ inch B2.3.3 High • faulting ½ inch or greater B2.4 Blowups – Blowups refer to localized upward movement of pavement surface at transverse joints, possible accompanied by shattering of concrete in the area on either side of the joint. Blowups can occur midslab at a transverse crack but these shall not be counted in this distress. If a joint is experiencing a blowup, there is no need to also record faulting or spalling at that joint. Record the number of transverse joints with a blowup. Divide the amount of affected joints at by the total number of joints in the segment. Multiply by 100 to determine the extent of segment affected. B2.5 Longitudinal Cracking – Longitudinal cracks are cracks predominantly parallel to the pavement centerline and propagate through the length of the slab. This may count a linear crack that separates a corner of a slab. This is

G-18 Performance-Based Pavement Warranty Practices sometimes referred to as a corner break but shall be recorded as a longitudinal crack if it is predominantly parallel to the pavement centerline. Rate the entire crack within a single slab at the highest level present for 10% or more of total crack length. Longitudinal cracks are recorded on a linear foot basis so if multiple longitudinal cracks are present on a single slab, record it as a single crack and increase the severity. For each severity, the total length of longitudinal cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B2.5.1 Low • unsealed cracks 0 – 1/8 inch wide, no faulting, no spalling • sealed cracks with sealant material in good condition, no faulting, no spalling B2.5.2 Medium • any crack 1/8 – ¼ inch wide, no faulting, no spalling • any crack less than ¼ inch wide with faulting up to ¼ inch • any crack less than ¼ inch wide with spalling up to 3 inches wide • any crack that would otherwise be considered Low Severity but is accompanied by additional Low Severity cracks that fragment the slab B2.5.3 High • any crack greater than ¼ inch wide • any crack with greater than ¼ inch faulting • any crack with greater than 3 inch wide spalling • any crack that would otherwise be considered Medium Severity but is accompanied by additional Low or Medium Severity cracks that fragment the slab B2.6 Longitudinal Joint Spalling – Longitudinal joint spalling refers to any cracking, breaking, chipping, or fraying of slab edges at longitudinal construction joints found entirely within travel lanes. Spalling includes any cracking within 1 foot of the face of the joint. Any longitudinal joint located within (or 1 foot from) the paint line separating a lane from a shoulder shall be evaluated with the lane edge spalling distress. Otherwise count spalling in whichever lane the joint is located. If a longitudinal joint is found within the divider line between travel lanes, consider that joint a part of the slower (right) lane. Spalling is counted as a distress to the joint so it does not matter which side of the joint experiences spalling. Spall width is based on the distance from the face of the joint to the end of displaced material on either side of the joint. If there is no loss of material but cracking is still present, the spall width is zero but it is still considered spalled at low severity. Severity of longitudinal joint spalling can change between each linear foot of pavement. Rate spalls at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the total length of longitudinal joint spalling measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. If multiple longitudinal joints are found within a single lane, extent could exceed 100%. This is relevant when slab widths are smaller than lane widths. B2.6.1 Low • spall widths up to 2 inches • joints with low severity cracking in crescent shaped patterns or parallel to the joint within 1 foot of the joint B2.6.2 Medium • spall widths 2 – 4 inches B2.6.3 High • spall widths greater than 4 inches B2.7 Lane Edge Spalling – Lane edge spalling refers to longitudinal joint spalling specifically between a travel lane and a shoulder. This includes both paved and unpaved shoulders. Spall width is based on the distance from the face of the joint to the end of displaced material on either side of the joint. If no material is displaced but cracking is still present, the spall width is zero but it is still considered spalled. In the case of unpaved shoulders, where there is technically no joint, spalling still can be experienced on the edge of the slab. Severity of lane edge spalling can change between each linear foot of pavement. Rate spalls at highest level present for 10% or more within each linear foot where appropriate. If severity changes frequently, inspector’s judgment should be applied. For each severity, the

West Virginia DOH Warranty Information G-19 total length of lane edge spalling measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. In the event of a one lane road with shoulders (paved or unpaved) on either side, lane edge spalling could be present on both sides, therefore, extent could exceed 100%. B2.7.1 Low • spall widths up to 3 inches • joints with low severity cracking in crescent shaped patterns or parallel to the joint within 1 foot of the joint B2.7.2 Medium • spall widths 3 – 6 inches B2.7.3 High • spall widths greater than 6 inches B2.8 D Cracking – D cracking, sometimes known as durability cracking, refers to closely spaced hairline cracking crescent shaped patterns that follow the edge of a slab near all joints. This is a very distinct distress that is usually caused by unideal properties of aggregate in concrete. It can increase in severity to entire slabs showing this patterned crack with significant loss of material across the surface. It is not to be confused with spalling which generally leads to loss of material specifically at the joint, or scaling which is usually a more random cracking pattern in the surface of the concrete. The total length of D cracking measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B2.9 Scaling – Scaling, also known as map cracking, refers to a series of interconnected cracks in the surface of concrete. This can range in severity from noticeable interconnected hairline cracks, to sections with significant loss of material across the surface. Generally, scaling will not result in displaced material deeper than ½ inch from the original pavement surface. The total length of scaling measured in linear feet will be divided by 528 and then multiplied by 100 to determine the percent of test section affected. B2.10 Patching – Patching refers to any portion of pavement surface that has been replaced or added to after the original construction. Full depth, full width repairs will not be considered patches. However, it should be noted that full depth repairs could change the amount of joints and slabs within test sections for future surveys. For example, a full depth repair on a joint will replace the existing joint with two spaced joints, where a full depth repair on a mid- panel crack will simply add two joints. Partial depth concrete repairs do not add to the number of joints, however, their length will be counted towards patching. All other distresses found within the patch shall still be recorded. Patching of any type, width, depth, etc. within the lane is recorded in linear feet. The total length of patching measured in linear feet will be divided by 528 and then multiplied by 100 to determine the extent of test section affected. B2.11 Popouts – Popouts are small pieces of pavement broken loose from the surface, normally ranging in diameter from 1 - 4 inches and depth from ½ - 2 inches. Take note if significant sections of pavement or entire slabs appear to exceed an average popout density of 3 popouts per square yard. Popouts are measured on a linear foot basis, so record the length of sections, or the length of slabs exhibiting excessive popouts. The total length in linear feet will be divided by 528 and then multiplied by 100 to determine the percent of test section affected. Section 636 Maintenance of Traffic 636.23 – Method of Measurement: Add the following subsection to the section: 636.23.30 – Lump Sum Traffic Control: Work under this Section consists of providing, installing and maintaining various traffic control devices for the protection of the traveling public and working personnel during construction and maintenance operations, and includes channelizing devices, signs, barricades, markings, lighting devices, flaggers, pilot trucks, traffic director, hand signal devices, and all other applicable methods as described in Section 636 and the Division’s Manual on Temporary Traffic Control for Streets and Highways, 2006 Edition. The Contractor shall be responsible for the installation of adequate safety precautions for the protection of the traveling public and his/her own personnel. All materials provided by the Contractor under the items of this section shall remain the property of the Contractor upon Completion of the project.

G-20 Performance-Based Pavement Warranty Practices All work under this Section shall be reviewed and accepted by the Engineer prior to installation of the traffi c control set up. 636.25 – Pay Items: ITEM DESCRIPTION UNIT 636001-001 Traffic Control Lump Sum Section 695 Mainline Pavement—Performance Paving 695.1-Description: This Special Provision shall define the requirements to construct a mainline pavement system, which includes roadway pavement, paved shoulders, and rumble strips, to the limits as shown by the contract plans and related documents. Excluding horizontal and vertical geometric improvements, the contractor shall construct a pavement system either asphalt or concrete, that shall meet all the criteria as defined by including, but not limited to, West Virginia Department of Transportation, Division of Highways Design Directives (DD’s), Standard Details Volume I, II, and III, American Association of State Highway and Transportation Officials (AASHTO) Policy on Geometric Design of Highways and Streets, “WVDOH Standard Specifications Roads And Bridges”, and all current supplemental, addenda and errata. The Contractor is advised that any proposed pavement system not designed using the above criteria shall be signed and sealed by a Professional Engineer licensed in West Virginia, however this system must be presented at the Proprietary Meeting. Additionally if the Contractor proposes a Pavement System not covered by the above criteria, the Contractor will allow the Division 30 days to establish Pavement Surface Rating criteria for the proposed system. The Contractor and the Division shall agree upon the new proposed rating system prior to any work being performed on the Project. However this 30 day review period will not affect the completion date of the Project. Asphalt Pavement System: An asphalt pavement system shall consist of all work and materials including asphalt wearing surface. The system may include, but is not limited to, an asphalt base courses, free draining base, fabric for separation, subgrade, underdrains, and subgrade preparation. Concrete Pavement System: A concrete pavement system shall consist of all work and materials. The system may include a free draining base, fabric for separation, subgrade, and subgrade preparation. 695.2–Restrictions: The Contractor is permitted to submit proposed Quality Control Plans for either pavement system or both and select the desired system at a later time. The entire “Mainline Pavement System” shall be constructed by a single pavement system. Any overlay equal to or less than two inches (</= 2 in), placed in the year of ninth performance rating period will require a three year warranty bond to ensure meeting the criteria as outlined in Section 490. The Division may or may not evaluate this addition warranty period annually, no bonuses or penalties shall be given after the final pavement surface rating according to Section 490. 695.3–Adjustments: 695.3.1–Material Adjustments: The following adjustments shall apply throughout the life of the pavement performance period. 695.3.1.1-Asphalt Adjustment: This Special Provision shall make use of the 2017 Standard Specifications and applicable Special Provisions for asphalt adjustments, except as described by this special provision. The proposed Job Mix Formula (JMF) submitted by the contractor, as described in Subsection 401.4.2, shall provide the quantity of asphalt cement, per square yard- inch (SY-IN), for each JMF. The asphalt adjustment shall be based on the lots used for thickness verification. If the pavement section is determined to be less than plan, the ratio of the average thickness to the plan thickness shall be applied to the asphalt cement quantity, for the lot considered for adjustment.

West Virginia DOH Warranty Information G-21 The bidding index (Ib) and the placement index (Ip) may be found posted at the Department Of Transportation’s website Contract Administration’s Lettings page: http://www.transportation.wv.gov/highways/contractadmin/Lettings/Pages/Fueland AsphaltPrices.aspx#CementPrices 695.3.1.2-Cement Adjustment: The compensation for the quantity of Portland cement used in the Concrete Pavement System shall be adjusted based on the latest published price, in dollars per ton, for Portland Cement (Type I) quoted for the average of Cincinnati and Pittsburgh in the Engineering News Record (ENR), Construction Economics Section available at the ENR website: http://enr.construction.com/economics/default.asp using the posted price as published on Wednesday of the first full week of the month. The adjustment shall apply regardless of an increase or decrease in the published price as described above. The contract items listed in the Proposal in the Table Of Materials To Be Adjusted For Price Of Portland Cement At The Time Of Placement will be adjusted in accordance with the Division’s indices for Portland Cement. The bidding index (Ib) for Portland cement will be equal to the placement index for the month immediately prior to the month in which the project is originally scheduled to be let. Any dispute concerning the bidding index shall be resolved during the first voucher estimate review. The placement index (Ip) will be the price in effect for the month in which the specified adjustable material was actually placed. Both the bidding index (Ib) and the placement index (Ip) will be based on the average of the posted prices described above. The bidding Portland cement index (Ib) and the placement cement index (Ip) may be found posted at the Department Of Transportation’s website Contract Administration’s Lettings page: http://www.transportation.wv.gov/highways/contractadmin/Lettings/Pages/FuelandAsphaltPrices.aspx#cementpr ices 695.3.1.3–Price Adjustment Formula: The portion of the contract unit price which reflects the cost of the specified material will be adjusted for the change in accordance with the following formula: = [( ÷ )− ] ( ) Where: Pa = Price Adjustment Ip = Price Index at time of placement Ib = Price Index for Bidding Q = “As Constructed” Quantity (converted to CY for Cement Adj.) (converted to TN for Asphalt Adj.) C = see below: C (asphalt) = refer to Section 109.10 ( )= ( )( ) Where: Ib = Price Index for Bidding Wc = tons cement per cubic yard from approved mix design Tadj = (tavg) / (tplan) as per 695.3.1.3 The price index for determining price adjustments for all work performed after the contract completion date, as revised by approved time extensions, will be determined as follows: The price index (Ip) shall be for the month in which the contract completion date (as extended), or the price index for the month in which the work was performed, whichever is less. The quantity of fly ash substitution shall not be included in the quantity eligible for adjustment. The Portland cement adjustment shall be based on the lots used for thickness verification. If the pavement section is determined to be less than plan, the ratio of the average thickness to the plan thickness shall be applied to the Portland cement quantity, for the lot considered for adjustment.

G-22 Performance-Based Pavement Warranty Practices 695.3.2–This section intentionally left blank 695.3.3–Fuel Adjustments: 695.3.3.1–Subgrade and Free draining Base: Any fuel adjustment for these items shall be applied directly to the subgrade and free draining base layers of the pavement section as per the table in Section 109.9 of the Standard Specifications. The quantities shall be determined by the cubic yard (CY) calculation that was placed for the respective items in a given month applying the specifications formulas accordingly. 695.3.3.2–Pavement System: The Contractor shall include the unit weight per SY-IN of the pavement system placed (excluding subgrade and free draining base) for the conversion to the Fuel Adjustment as described in Subsection 109.9 Table Of Materials To Be Adjusted And Cost Adjustment Factors For Diesel Fuel Usage. For this adjustment, the total square yardage will be the measured quantity accepted and the thickness in inches will be based upon the lots as established for thickness verification. If the pavement section is determined to be less than plan, the ratio of the average thickness to the plan thickness shall be applied to the Fuel Adjustment quantity, for the lot considered for adjustment. 695.4-Method of Measurement: The quantity of Mainline Pavement to be paid for will be the number of square yards (meters) complete in place and accepted. The width for measurement will be the width of the pavement shown on the surface of the typical cross section of the Plans and additional widening where called for or as otherwise directed in writing by the Engineer. This width shall be verified by field measurements. Widths exceeding the plan dimensions shall not be paid for. The length will be measured on the surface along the centerline of each roadway ramp. Bridge approach expansion joints will be measured separately and shall be the actual number of joints constructed, complete in place and accepted. Mainline Pavement is to be placed on all side roads up to the edge of the radius return furthest from the edge of mainline traveled way as shown by the detail in the plans. No additional square yard payment shall be made after any initial work is complete and after the terms of Initial Acceptance (Section 490.2) are met. No additional payment for Permanent Pavement Markings or Delineators will be made after the Date of Initial Acceptance for Performance work as defined in Section 490. Any pavement markings, delineators or rumble strips removed by necessary corrective action for work shall be replaced by the Contractor at his or her expense and shall meet the requirements of Section 663. Temporary Pavement Markings are no substitute for Permanent Pavement Markings. The Contractor may be able to coordinate work with regularly scheduled Statewide Paving Contracts, if approved by the Engineer and the Statewide Striping Contractor. 695.5-Basis of Payment: 695.5.1-General: The quantities, determined as provided above, will be paid for at the contract unit prices less adjustments as required by the specifications, which shall constitute full compensation for furnishing all materials as described in the item’s specification and all labor, equipment, tools, field laboratory, supplies and incidentals necessary to complete the work. 695.5.2-Progress Payments: The Progress Payment Schedule shall be based upon the pavement system as proposed by the Contractor. This schedule is intended to compensate the contractor for the material and work accepted. This project will require a CPM schedule, and the Contractor shall designate an activity for Item 695009-* in the Construction Schedule. Current Estimate Payments will be determined by the percent complete for that designated activity on the Construction Schedule as submitted and reviewed by the Engineer. 695.6-Pay Item: ITEM DESCRIPTION UNIT 695009-001 Mainline Performance Pavement System, “Year-duration”** Square Yard ** “Year-duration” – supplemental description for the year in which the Performance Pavement System was bid and duration in years (i.e., 2011-9, 2012-10)

Abbreviations and acronyms used without definitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACI–NA Airports Council International–North America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FAST Fixing America’s Surface Transportation Act (2015) FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TDC Transit Development Corporation TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S. DOT United States Department of Transportation

TRA N SPO RTATIO N RESEA RCH BO A RD 500 Fifth Street, N W W ashington, D C 20001 A D D RESS SERV ICE REQ U ESTED N O N -PR O FIT O R G . U .S. PO STA G E PA ID C O LU M B IA , M D PER M IT N O . 88 Perform ance-Based Pavem ent W arranty Practices N CH RP Synthesis 553 TRB ISBN 978-0-309-48155-7 9 7 8 0 3 0 9 4 8 1 5 5 7 9 0 0 0 0

Performance-Based Pavement Warranty Practices Get This Book
×
 Performance-Based Pavement Warranty Practices
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Pavement warranties have been common in the United States at various points in time, coming back into favor during the 1990s. While there is no national pavement warranty standard, agencies have developed their own specifications with varying criteria.

The TRB National Cooperative Highway Research Program'sNCHRP Synthesis 553: Performance-Based Pavement Warranty Practices documents highway agency practices associated with the use of performance-based pavement warranties, focusing on asphalt, concrete, and composite pavement projects (new, preservation, and rehabilitation) with warranty periods of at least one year.

READ FREE ONLINE

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!