Guidelines for the Use of Pavement Warranties on Highway Construction Projects (2011) / Chapter Skim
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Pages 5-35
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From page 5... ...
These statelevel evaluations and selected pavement warranty specifications can be found on the FHWA's National Highway Specifications website at www.specs.fhwa.dot.gov. The findings from these sources formed the basis for the final guidelines and model specifications developed under this research effort and are documented in the following sections of this chapter.
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From page 6... ...
Warranty Types The workshop participants first considered and discussed warranty types/classifications and definitions. In general, warranty provisions have been implemented in conjunction with both method specifications under traditional design– bid–build delivery and performance specifications under design–build project delivery.
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From page 7... ...
When the DOT survey evaluations were conducted as part of this research effort, classifications of warranty projects characterized by DOTs in terms of materials and workmanship and short-term or long-term performance were retained; however, the following classifications for these three types of warranties are offered based on the preponderance of the warranty specifications reviewed and the general consensus of the workshop participants. Type 1 Warranties Type 1 (materials and workmanship)
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From page 8... ...
Type 3 warranties typically use higher-level performance criteria, establishing pavement performance standards or thresholds that the contractor must maintain for the service life of the pavement or beyond, and include planned and unplanned maintenance. As shown in Figure 5, the contractor involvement extends from design through construction and includes planned maintenance.
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From page 9... ...
This includes the distress measurement technique, the frequency and repeatability of measurement, the tolerances, the tester qualifications, and the test equipment calibration.
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Warranty provisions are sole measure of quality. -Meets broad parameters established by owner with mix work done with proprietary procedures.
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This includes the distress measurement technique, the frequency and repeatability of measurement, the tolerances, the tester qualifications, and the test equipment calibration. Determine a rational way to measure traffic if it is included as a limiting factor in performance.
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Also, to avoid issues related to excessive 12 Performance Parameter/Distress Within Contractor's Control Measurable & Quantifiable Remarks Smoothness Y Y Can establish standards based on rehabilitation versus new pavements versus thickness of lifts. Transverse and longitudinal cracking Y*
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From page 13... ...
The lower costs applied to rubberized asphalt concrete open graded high binder, polymer modified chip seals, dense graded asphalt concrete, and bonded wearing course. 13 Distress indicators and thresholds Identify typical and potential performance values that could be established for warranties and identify primary and secondary causes of distress evitcejbO tnioP noissucsiD General information Understand the background of pavement warranties in the DOT slairetam neewteb sehsiugnitsid TOD eht woh dnatsrednU ytnarraw fo epyT and workmanship and performance Guidelines and implementation Understand how guideline and implementation procedures are determined and conveyed to others etadidnac gninimreted rof ygolodohtem eht dnatsrednU noitceles tcejorP warranty projects Effects on contracting process Understand the effect of warranty on procurement, competition, and construction Warranty management Understand the responsibility of each party during the warranty period Benefits and future considerations Determine the perceived and/or documented benefits of implementing warranty projects Table 5.
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From page 14... ...
Colorado DOT (CDOT) CDOT has experience with materials and workmanship and performance warranties, having implemented 3-, 5-, and 10-year HMA pavement warranty projects and 5- and 10-year PCC pavement projects.
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Additionally, while every effort was made to match similar control projects to warranty projects for comparative purposes, in most cases the rehabilitation strategies did not match exactly, which may have contributed to the differences in the performance data. Table 7 shows the rehabilitation strategies on the warranty and the control projects.
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From page 16... ...
IDOT reported that this is an acceptable workload for district engineers since each district has only a few warranty projects, but as that number grows, dedicated personnel would be necessary to manage all the warranties. IDOT published an evaluation report in 2004; however, since none of the projects had reached the end of their warranty period and several were still under construction at that time, it was recommended that a decision on whether to continue the use of warranties be deferred until more performance data became available (Wienrank, 2004)
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• Warranties do not promote innovation because they require contractors to minimize risk, which is accomplished by relying on what has been proven to work. Iowa DOT is better suited to shoulder the risk associated with innovation.
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Materials and workmanship warranty projects may have one inspector assigned to five projects at a given time, while performance warranties may not be inspected until final acceptance. Approximately 3% of all projects require remedial action, and there have been relatively few documented cases of disputes.
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Mississippi DOT developed a software program (DEDUCT) that translates different distress thresholds for pavement performance measures into a common point system for pavement distress.
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The committees also established the bond price, which was based on the estimation of the typical repairs costs. ODOT stated that project selection criteria for warranty projects included simple projects with well-defined pre-existing conditions and overall consistency compared to a typical urban main-street project in a downtown area where there are many crossings, signals, and transitions.
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From page 21... ...
TxDOT has developed warranty specifications for hot-mix asphalt concrete, surface treatments, and microsurfacing, but has only implemented the microsurfacing specification. TxDOT reported issues in developing reliable thresholds for pavement warranties due to inconsistencies in its historical performance data, both in the type of pavement characteristic measured and how these characteristics were measured.
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From page 22... ...
This cost comparison concluded that even where an initial cost was up to 7% greater, warranty pavements were still more cost effective than standard pavements. The report also examined the comparative performance data on the warranty and non-warranty projects over the 5-year period.
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Another programmatic-level criterion that appeared to play a part in the project selection criteria was level of industry cooperation. Mississippi DOT reported that the level of competition on warranty projects varied among districts, which often plays a role in the decision to apply a warranty.
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From page 24... ...
Most practitioners would agree that key technical and managerial elements must be considered in guidelines as part of implementation regardless of objectives for use or type of warranty. In addition to project selection criteria, other key considerations include selecting performance indicators, setting distress thresholds, warranty durations, bonding, and risk allocation and contracting considerations.
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From page 25... ...
For example, Illinois DOT described reviewing sample specifications from other DOTs, national reference manuals, historical performance data, and statistical analyses and using a joint DOT–industry work group to develop its performance-based warranty specifications. Table 13 shows representative samples of performance indicators used to gauge performance on warranty contracts.
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From page 26... ...
Threshold values are structured several different ways. Some performance indicators use a single, minimum threshold value, while others may specify levels of thresholds with different remedial procedures that correspond to the severity of the distress.
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The manner in which performance data is tracked and evaluated should be considered when setting threshold values. Selecting performance indicators similar to distresses tracked under the standard pavement management system is useful for developing comparative performance data; however, consideration should be given to the length of the segment over which data points are measured when setting thresholds.
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PMS data for IRI and rutting for INDOT 10-year HMA using a high-speed inertial profiler and rut bar based on 1.0 mile segment lengths. Figure 7.
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From page 29... ...
. An example of deterioration curves using regression analysis for data from different aged HMA pavement from the Indiana DOT's Interstate highway system is shown in Figure 9.
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The warranty bond is $2,000,000.00 for the warranted HMA/SMA pavement. The bond is intended to insure completion of required warranty work, including payments for all labor, equipment, materials, and closure periods used to remediate any warranted pavement distresses.
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From page 31... ...
Some performance warranty provisions also give contractors control over the methods used to construct the work. Based on the interview responses and an examination of specifications, it was difficult to classify some of the pavement specifications as material and method versus performance because of subtle differences in responsibility for mix design.
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From page 32... ...
Again, the warranty provisions should clearly define the roles and responsibilities of each party for inspection and testing in the warranty provisions. Alternative Contracting Design–Build–Warranty Recent international scan studies have reported that European agencies routinely use warranties in conjunction with design–build contracting and rely more on the private sector to maintain and operate highways.
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Depth measured using an automated device in compliance with Texas DOT standards. Straightedge used to measure rut depth for localized areas.
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From page 34... ...
If the contractor does not agree with the survey results or the scope of the remedial work or believes that the cause of the distress was beyond its control, it can dispute the results and refer the matter to a dispute resolution team or board to render a final or independent decision. Dispute Resolution Procedures Most warranty provisions establish measures for settling disagreements for potential disputes over remedial action.
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From page 35... ...
These guidelines and specifications have been updated in this report to reflect the current state of practice for warranties, including project selection criteria for warranty types, risk allocation based on contract type, and model specifications for both HMA and PCC pavements covering both materials and workmanship and performance warranties. The next chapter discusses the approach to developing these guidelines.
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