Samuel LabiGeoffrey LampteySravanthi KonduriKumares C. Sinha...
p.3-12页
查看更多>>摘要：Thin hot-mix asphalt (HMA) concrete overlays are preventive maintenance treatments used to address minor distresses, increase ride quality, and extend pavement life. This paper determines the long-term effectiveness of such treatments by using three measures of effectiveness: treatment service life, increase in average pavement condition, and area bounded by the performance curve. For each measure of effectiveness, the pavement performance indicators used are the international roughness index (IRI), rutting, and pavement condition rating (PCR). For each measure of effectiveness and performance indicator, treatment benefits were found to lie within a wide range because of the effect of varying levels of weather severity, traffic, and route type. The service life of the treatment ranges from 3 to 13 years (IRI performance indicator), 3 to 14 years (rutting), and 3 to 24 years (PCR). When the increase in average pavement condition is used as the measure of effectiveness, the results show that such treatments offer 18% to 36% decrease in IRI, 5% to 55% reduction in rutting, and 1% to 10% increase in PCR. For the area enclosed by the performance curve, thin HMA overlay effectiveness ranges from 40 to 360 IRI years (where IRI is in inches per mile), 0.13 to 0.76 RUT years (where RUT is in inches), and 7 to 130 PCR years (where PCR is on a 0 to 100 scale). The wide ranges of thin HMA overlay effectiveness for each combination of measure of effectiveness and performance indicator is suggestive of the sensitivity of the treatment effectiveness to levels of traffic loading and weather severity, and route type. The effectiveness of thin HMA overlay treatments is of interest to pavement professionals and is a vital input in the quest for cost-effective long-term pavement preservation practices.
查看更多>>摘要：This paper describes a recent research study that examined how changes in design life affected the pavement life-cycle cost and ultimately how the reduction in or addition to life-cycle cost attributed to superior or inferior in-service performance could be used as a basis for establishing a pay factor for a performance-based specification. Previous models were developed with data from the Canadian Long-Term Pavement Performance Program, which indicated that overlay thickness, total prior cracking, annual freezing index, annual days with precipitation, and accumulated equivalent single-axle loads (ESALs) after 8 years affected the slope of pavement deterioration for asphalt overlay pavements. One of these models, as well as data from the U.S. Long-Term Pavement Performance test sites, is used to determine the service life of asphalt overlay pavements. This paper examines how the variability associated with overlay thickness, total prior cracking, and accumulated ESALs after 8 years affects the service life of asphalt overlay pavements. Furthermore, this paper considers the variability associated with the discount rate and incorporates all associated variability into the life-cycle cost analysis (LCCA). LCCA is performed by using Monte Carlo techniques. On the basis of a recent study, distributions for service life and life-cycle costs are developed by using both normal and lognormal distributions for overlay thickness. With the LCCA values for typical design lives, a sensitivity analysis is subsequently performed to evaluate the impact of 10%, 20%, and 30% differences in the in-service performance as compared to the design life. These LCCA differences are then used as a basis for establishing pay factors. Overall the paper attempts to relate design to in-service performance life-cycle cost and the ultimate use of pay factors.
查看更多>>摘要：Pavement warranty is an innovative contracting procedure increasingly adopted by highway agencies. Many states view implementing warranties as a way to protect their investment in pavement construction. The major benefit of pavement warranty is enhanced pavement performance. However, establishing warranty criteria and monitoring the performance of warranted pavement are two technical issues that must be resolved. This paper presents the discoveries of a research project supported by FHWA to investigate the effectiveness of using the pavement management system (PMS) to monitor the performance of pavement under warranty. It has been discovered that most states establish their warranty specifications on the basis of performance data from their PMS database by using statistical analyses, expert opinions, and adaptation of other states' specifications. They also use the PMS data to monitor the performance of both warranty and nonwarranty pavements because the essential data, like ride, cracking, and rutting, are available in the database and are convenient for use. This paper also documents the unique features of the warranty specifications, including the warranty period, performance indicators, data collection methods, performance thresholds, remedial actions, and how the PMS database can be used to track the performance of pavements under warranty in five states: Indiana, Wisconsin, Ohio, Florida, and Michigan. Some comparisons of the performances of the warranted pavements and those of nonwarranted pavements of similar conditions are also presented. The survey indicated that an integrated PMS that links the materials and traffic database would offer better efficiency to monitor and analyze the performance of both warranty and nonwarranty pavements.
查看更多>>摘要：One of the biggest challenges for any public organization is how to prioritize projects to maximize existing funding. With so many programs competing for the same funding, it is especially important to optimize pavement rehabilitation programs to allow for funding for other programs, such as safety, capacity improvements, and environmental improvement projects. This report describes how the Nevada Department of Transportation (NDOT) optimized its available funding while improving pavement condition by using an eight-step pavement management system based on financial consequence. This eight-step procedure includes administration support, contract database implementation, roadway system division, performance models, project prioritization, and strategy selection. This procedure can easily be adopted by other states. A nominal amount of information is required to initiate this system, and the reward can be exceptional. NDOT saves $42 million a year with this methodology. An advantage of a pavement management system based on financial consequence over a conventional network optimization system is that process allows engineers to communicate with top administrators in a nontechnical way. Administrators can understand the concept and make good roadway funding choices without needing a great deal of technical input from engineers. For example, administrators see that the cost of delaying a 10-mi roadway section on an Interstate system by 2 years can cost the agency an additional $6 million for rehabilitation; but that delaying a 10-mi roadway section on a relatively low-volume road can cost only a few thousand dollars.
查看更多>>摘要：It is widely accepted that the success of pavement management systems largely depends on the quality of the deterioration models embedded in their structure. As such, much research has concentrated on developing a large array of approaches to model and predict pavement distress and deterioration. This study develops surface distress prediction models for pavement failure times (the initiation of cracking on the surface of flexible and semirigid pavements) on the basis of a large (more that 1,000 observations) and recent (1998) data set collected from in-service pavements in 15 European countries by using the principles of stochastic duration (hazard) models. The results indicate that, as expected, construction, traffic, and climatic factors affect pavement distress and that the lognormal functional form, in contrast with the findings of previous studies, best describes the distress initiation process.
Theodore H. PoisterPhilip M. GarveyAbdulilah Z. ZineddinMartin T. Pietrucha...
p.43-51页
查看更多>>摘要：This paper reports the findings of research conducted for the Pennsylvania Department of Transportation (PennDOT) to develop customer-based standards for ride quality on four functional classes of highway: Interstate highways, other national highway system (NHS) roads, secondary roads with average annual daily traffic (AADT) greater than 2,000, and secondary roads with AADT less than 2,000. The field work, in which subjects evaluated the ride quality of predetermined test sections of pavements, was conducted in six Pennsylvania counties to incorporate a variety of settings across the state. These subjective ratings were regressed on international roughness index (IRI) values for each of the four highway classes and revealed a fan-shaped pattern in which motorist satisfaction with ride quality dropped off with increased roughness most sharply on Interstate highways, less so for other NHS roads, and still less for secondary roads. PennDOT's current standards for what constitutes good ride quality for each of the four road types equates closely with the 70% level of motorist satisfaction, whereas the standards for excellent ride quality coincide with the 90% motorist satisfaction level for all but the lower-volume secondary roads. The results also suggest that motorist satisfaction with ride quality is extremely sensitive to IRI in rural settings, moderately sensitive to IRI in urban settings, and less so in major metropolitan suburban areas. This pattern is the reverse for NHS roads, and for secondary roads motorist satisfaction is very sensitive to IRI in rural areas and less so in urban and suburban areas. From these results, PennDOT could consider adopting more ambitious ride quality standards, targeting even higher levels of customer satisfaction. However, adopting such standards would require a careful analysis of the cost implications, which is beyond the scope of the research reported here.
查看更多>>摘要：The Alabama Department of Transportation (ALDOT) has used a vendor to perform automated pavement condition surveys for the Alabama pavement network since 1997. In 2002, ALDOT established a quality assurance (QA) program to check the accuracy of the automated pavement condition data. The QA program revealed significant discrepancies between manual and automatically collected data. ALDOT uses a composite pavement condition index called pavement condition rating (PCR) in its pavement management system. The equation for PCR was developed in 1985 for use with manual pavement condition surveys; however, ALDOT continues to use it with data from automated condition surveys. Since the PCR equation was developed for manual surveys, the discrepancies between the manual and automated data led ALDOT to question the continuity between its manual and automated pavement condition survey programs. A regression analysis was completed to look for any systematic error or general trends in the error between automated and manual data. Also, Monte Carlo simulation was used to determine which distress parameters most influence the PCR and whether they require more accuracy. The regression analysis showed the following general trends: automated data overreport outside wheelpath rut depth, under-report alligator severity Level 1 cracking, and overreport alligator severity Level 3 cracking. Through Monte Carlo simulation, it was determined that all severity levels of transverse cracking, block cracking, and alligator cracking data require greater accuracy.
查看更多>>摘要：To select the optimal strategy for treatment of a cracked asphalt pavement, it is important to determine the extent of cracking (partial depth or full depth). This paper presents the results of an explanatory study aimed at examining the applicability of the ultrasonic technology for evaluation of cracks and longitudinal joints in flexible pavements. It was shown that this technology, which has been used successfully for many years for the evaluation of concrete structures, could provide a simple, quick, and objective procedure for evaluation of surface distresses in asphalt concrete pavements. The results of laboratory testing and field testing at the Minnesota Road Research Project test facility demonstrate the potential of this technology.
Imad L. Al-QadiSamer LahouarKun JiangKevin K. McGhee...
p.69-78页
查看更多>>摘要：In this paper, the accuracy of ground-penetrating radar (GPR) for estimating pavement layer thicknesses is studied on the basis of the investigation of 17 pavement sites in Virginia. The considered sites have different types of pavement systems (flexible, continuously reinforced, jointed concretes, and composite) and different ages (0 to 5 years; 10 to 15 years; older than 20 years with a surface less than 10 years; and older than 20 years with a surface older than 10 years). Because of the diversity of the test sections considered, the accuracy of the GPR thicknesses was studied for pavement age for the same type of pavement and against pavement type for sites of the same age category. For flexible pavements, the GPR thickness error was found to increase as the pavement's age increased (4.4% error for pavements 0 to 5 years old versus 5.8% error for pavements older than 20 years with surfaces older than 10 years). Moreover, for the same age category, flexible pavements were found to have a relatively high thickness error (4.4%) compared with the continuously reinforced concrete pavements (3.0%) and with the jointed plain concrete pavements (2.3%) because of the relative homogeneity of concrete for electromagnetic wavelength when compared with the different dielectric profile of aged hot-mix asphalt layer.
Parisa ShokouhiNenad GucunskiAli MaherSameh M. Zaghloul...
p.79-88页
查看更多>>摘要：Discrete wavelet transform (DWT) was proposed as a new diagnostic tool for locating various frequency-related features of profiles, such as repeated waves and short-lived surface distress, that affect ride quality. The shortcomings of power spectrum density (PSD) analysis in evaluating the distribution of energy of a profile between various frequency band-widths were pointed out. The theoretical background and the basics of the DWT decomposition algorithm are discussed. Advantages of DWT analysis over PSD analysis in detection of short-lived features of the profile are illustrated by an example. The results of both the PSD and DWT analyses of three profile data, taken from data collected as a part of an ongoing research project sponsored by New Jersey Department of Transportation, are presented. The results indicate that DWT analysis can capture both short-lived high-frequency and long-lived low-frequency features of the profile and, consequently, provides a better representation of the profile characteristics. The application of DWT in the development of new ride indices is also discussed.
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