U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
REPORT |
This report is an archived publication and may contain dated technical, contact, and link information |
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Publication Number: FHWA-HRT-11-070 Date: July 2012 |
Publication Number: FHWA-HRT-11-070 Date: July 2012 |
Long-life pavements are needed to handle the congestion and traffic loading that pavements will experience in their lifetime. To meet a 30-year calendar design life, a pavement built today may need 70–100 percent more axle loads per mile than a similar pavement built 10 years ago.
One method for evaluating the performance of a particular pavement design is through accelerated loading at test tracks or ALFs. ALFs provide valuable performance data that allow engineers to improve current procedures and advance the state of the art. Throughout the 1980s and 1990s, many new accelerated testing programs with ALFs were installed. ALFs encourage innovation by eliminating the fear of failure associated with full-scale road testing, since ALFs can test innovations without the possibility of disastrous consequences that might occur on a real highway. ALFs also provide small-scale evaluation of full-scale designs to identify limitations and speed up the implementation of design improvements. At least 24 ALFs currently operate in the United States.
Data collection methods for monitoring test roads and in-service pavements can be developed and expanded further. Continuously monitoring pavement performance will help improve concrete pavement design procedures, construction standards and specifications, and rehabilitation techniques. Developing a performance feedback loop to provide continuous condition reports will allow prompt improvements to existing pavements that fall short of user needs. Additional data are also needed for new materials, new test sections, model validation and calibration, innovative joint designs, and surface characteristics advancements. This data can contribute to many of the research tracks in the CP Road Map, which depend on quality data for validation or calibration and require experimental installations or access to long-term data from in-service pavements.
The following research areas are needed to design, build, evaluate, and monitor long-life pavements:
The problem statements in this track will identify both conventional and innovative pavement types, design features, foundations, materials, construction QC/QA, and preservation treatments that will provide the traveling public with a long-life concrete pavement requiring minimal lane closures for maintenance or rehabilitation over the design life.
The track 9 objectives are as follows:
The track 9 research gaps are as follows:
The track 9 research challenges are as follows:
Table 49 shows the estimated costs for this research track.
Problem Statement | Estimated Cost |
Subtrack 9-1. Technologies for Measuring Concrete Pavement Performance | |
9-1-1. Stress-Sensing Concrete Pavements | $500,000–$750,000 |
9-1-2. Self-Inspecting Smart Concrete Pavements | $500,000–$750,000 |
9-1-3. Rolling Wheel Deflectometer for Concrete Pavements | $500,000–$750,000 |
Subtrack 9-2. Strategies for Long-Life Concrete Pavements | |
9-2-1. Identifying Long-Life Concrete Pavement Types, Design Features, Foundations, and Rehabilitation/Maintenance Strategies | $800,000–$1.2 million |
9-2-2. Design Catalog for Long-Life Concrete Pavements | $500,000–$1 million |
9-2-3. Strategic Application of Preservation Treatments to Preserve Long-Life Concrete Pavement | $500,000–$700,000 |
Subtrack 9-3. Construction Techniques and Materials Selection for Long-Life Concrete Pavements and Overlays | |
9-3-1. Development of Quality Control/Quality Assurance Testing Standards to Ensure Long-Life Concrete Pavements | $500,000–$600,000 |
9-3-2. Identification of Material Requirements and Tests for Long-Life Concrete Pavements | $1–$1.5 million |
9-3-3. Design, Construct, and Evaluate Experimental Long-Life Concrete Pavements | $3–$5 million |
9-3-4. Design, Construct, and Evaluate Concrete Overlays | $3–$5 million |
Subtrack 9-4. Planning and Design of Accelerated Loading and Long-Term Data Collection | |
9-4-1. Identification of Accelerated and Long-Term Data Needs | $750,000–$1.5 million |
9-4-2. Concrete Pavement Data Management and Distribution | $800,000–$1.2 million |
9-4-3. Master Plan for Conducting Accelerated Testing of Products and Full-Scale Road Experiments | $900,000–$1.5 million |
9-4-4. Develop Experimental Designs and a Data Collection and Performance Monitoring Plan for Accelerated Loading Facilities and Full-Scale Products Testing | $800,000–$1.5 million |
9-4-5. Concrete Pavement Rating System for Highways | $200,000–$400,000 |
Subtrack 9-5. Preparation of Data Collection/Testing Procedures and Construction of Test Road | |
9-5-1. Preparation of Concrete Pavement Data Collection and Testing Procedures | $500,000–$1 million |
9-5-2. Construction of Accelerated Loading Sections and Test Road Sections | $4.8–$7.2 million |
Subtrack 9-6. Long-Life Concrete Pavement Performance Implementation | |
9-6-1. Implementation of Long-Life Concrete Pavements | $800,000–$1.2 million |
9-6-2. Implementation of Accelerated Loading and Long-Term Data Collection | $800,000–$1.2 million |
Total | $21.2–$34.0 million |
Track 9 problem statements are grouped into the following six subtracks:
Each subtrack is introduced by a brief summary of the subtrack’s focus and a table listing the titles, estimated costs, products, and benefits of each problem statement in the subtrack. The problem statements follow.
This subtrack will develop and evaluate new technologies for measuring concrete pavement performance. Table 50 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-1-1. Stress-Sensing Concrete Pavements | $500,000–$750,000 | Evaluation of stress-sensing monitors that record actual wheel-load stresses over concrete pavement life. | Measurement of actual wheel-load stresses over concrete pavement life. |
9-1-2. Self-Inspecting Smart Concrete Pavements | $500,000–$750,000 | Evaluation of potential smart sensing and communicating technologies that could be integrated into the concept of self-inspecting concrete pavements. | Smart and self-inspecting concrete pavements. |
9-1-3. Rolling Wheel Deflectometer for Concrete Pavements | $500,000–$750,000 | A rolling wheel deflectometer that can be operated at various speeds and addresses specific concrete pavement technology issues. | Assessment of pavement condition using a rolling wheel deflectometer at operating speed. |
When concrete pavements are designed, fatigue damage is anticipated by estimating the total number of all weights and types of axle loads that the pavement will experience over its lifetime. Weigh-in-motion sites are often unavailable; however, fully measuring the number and weight of axle loads that the pavement actually experiences over its lifetime is nearly impossible. Overweight trucks are known to damage a pavement more significantly than trucks with legal axle weights, but special permit trucks with heavier than legal weights are allowed to use the pavement.
This problem statement will investigate the viability of stress-sensing pavements that can measure and log wheel load stresses over the pavement life. Stress can be measured indirectly through instantaneous strain or deflection under a wheel load. Pavement stresses from environmental loading also can be measured. This stress-sensing technology can lead to smart pavements that predict remaining pavement life or time until rehabilitation. The technology will also provide better information to pavement designers about when and how to design a rehabilitation alternative.
The tasks include the following:
Benefits: Measurement of actual wheel load stresses over concrete pavement life.
Products: Evaluation of stress-sensing monitors that record actual wheel load stresses over concrete pavement life.
Implementation: This research will provide the groundwork for additional research into other sensing and self-inspecting concepts, such as that in problem statement 9-1-2.
This problem statement will investigate the viability of a pavement that is capable of continuously and remotely monitoring key behaviors that ultimately can be tied to structural or functional degradation. For example, embedded sensors can be used to monitor load (stresses or strains), compressive stress buildup over time (blowups), climatic changes (temperature and moisture), and deflections (joint LTE, joint faulting, and corner deflection). This smart pavement concept will benefit the industry in a number of ways. For example, critical events such as an overloaded vehicle or a climatic anomaly can be detected. Potential blowups can be detected long before the probability of one is significant, so that action can be taken to relieve the pressure. In addition, the collected data can help improve concrete pavement design, construction, and maintenance continuously and establish more rational performance standards for concrete paving.
The tasks include the following:
Benefits: Smart and self-inspecting concrete pavements.
Products: Evaluation of potential smart sensing and communicating technologies that could be integrated into the concept of self-inspecting concrete pavements.
Implementation: This research may require a preceding investigation of available sensors (see problem statement 9-1-1), which may in turn lead to more long-range research efforts.
Operating speed deflection testing equipment that determines deflections in concrete pavements is missing from today’s pavement condition assessments. System-wide deflection data are the missing component of a network analysis method that requires IRI, distress survey, climatic, and traffic data to understand pavement performance fully and evaluate pavement rehabilitation strategies adequately.
The currently used falling weight deflectometer (FWD) test can perform individual test setups, but gaining access to busy roadways during the peak measurement times is becoming increasingly difficult. FHWA is developing a rolling deflectometer based on laser technology but has yet to prove the concept sufficiently for concrete pavements. The rolling dynamic deflectometer at the University of Texas has produced excellent data, but it is only a prototype and moves at 1.5 mi/h. This research will evaluate prototype defection equipment at various operating speed capabilities.
The tasks include the following:
Benefits: Assessment of pavement condition using a rolling wheel deflectometer at
operating speed.
Products: A rolling wheel deflectometer that can be operated at various speeds and addresses specific concrete pavement technology issues.
Implementation: This work will result in a long-term implementation strategy for promising deflection prototype devices. While this technology should operate at typical highway speeds, devices that operate at lower speeds will be evaluated due to the unique concrete pavement response issues.
This subtrack structures the approach to long-life pavements from the strategic approaches to the design catalogs. The problem statements in this subtrack rely on the work conducted under track 2. Table 51 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-2-1. Identifying Long-Life Concrete Pavement Types, Design Features, Foundations, and Rehabilitation/ Maintenance Strategies | $800,000–$1.2 million | Feasible pavement strategies and promising features for providing long life for each type of concrete pavement selected and case studies of past long-life concrete pavements. | Feasible pavement strategies for providing long life that will provide input throughout track 8. |
9-2-2. Design Catalog for Long- Life Concrete Pavements | $500,000–$1 million | An interim design catalog of long-life pavement designs (produced within 2 years of starting) and contents that will be updated as more information obtained from research activities under this track becomes available. | A catalog of long-life pavement designs that will provide practicing engineers with the tools for designing long-life cost-effective pavements with minimal restoration and rehabilitation. |
9-2-3. Strategic Application of Preservation Treatments to Preserve Long-Life Concrete Pavement | $500,000–$700,000 | Recommendations on the type, design, construction, and optimum application timing of restoration or rehabilitation treatments for extending pavements service life or indefinitely preserving the original pavement structure. | Recommendations on the optimum application timing of restoration or rehabilitation treatments that will extend pavement service life or indefinitely preserve the original pavement structure and a tool for practicing engineers to use in designing long-life cost-effective concrete pavements with minimal restoration. |
This research will identify both conventional and innovative pavement types likely to provide a long life, including an evaluation of the advantages and limitations of different pavement designs for long-life applications and the possible preservation strategies for each pavement type. With certain pavement types, pavement service life may be significantly extended through preservation treatments, although in some design situations, any major pavement treatment within a certain period may be unacceptable. Examples of promising design features include continuous reinforcement, widened slabs, stabilized base, positive subdrainage, large-diameter dowel bars, and uniform and stable foundations. This research will investigate various means of satisfying the long-life pavement goals, considering the entire pavement life cycle and including rehabilitations where appropriate. Site conditions, such as traffic level, subgrade properties, climate, and local aggregate and material properties, significantly affect pavement performance, and feasible pavement strategies will be identified in light of such factors.
The tasks include the following:
Benefits: Feasible pavement strategies for providing long life that will provide input throughout track 9.
Products: Feasible pavement strategies and promising features for providing long life for each type of concrete pavement selected and case studies of past long-life concrete pavements.
Implementation: This research will be coordinated closely with work in tracks 2 and 6. Case studies and the identification of promising types and design features developed in this research will be essential to the rest of this track.
This research will develop a catalog of long-life pavement designs that lists feasible pavement design alternatives for different site conditions. The design conditions may be classified in terms of climatic region (or key climatic factors), traffic level, and subgrade or foundation type. Each design entry in the catalog will describe the structural section (base/subbase type and thickness and slab thickness), slab width, joint spacing, material requirements, and other design features such as load transfer design and subsurface drainage. While the catalog will discuss slab thickness in relation to other design features, slab thickness will not be included in each section of the catalog because thickness requires detailed analyses in light of all other design features and site conditions. Instead, the design catalog will focus on design aspects other than slab thickness. It will also provide QC/QA testing guidelines to ensure adequate construction quality for all layers and the foundation. Based on available information, an interim guide will be developed that will be updated based on the results of other research conducted under this track.
The tasks include the following:
Benefits: A catalog of long-life pavement designs that will provide practicing engineers with tools for designing long-life cost-effective pavements with minimal restoration and rehabilitation.
Products: An interim design catalog of long-life pavement designs (produced within 2 years of starting) and contents that will be updated as more information obtained from research activities under this track becomes available.
Implementation: This research will be coordinated closely with work in track 2. The research will result in a practical product for immediate use in designing long-life concrete pavements.
Through strategic use of restoration and rehabilitation techniques, extending the service life of concrete pavements may be possible. This research will investigate the feasibility of applying restoration or rehabilitation treatments to preserve and further extend the service life of long-life pavements. All possible alternatives should be considered including CPR treatments and concrete overlays. The optimum application timing, based on pavement condition and rehabilitation objectives, should also be determined. Finally, the feasibility of indefinitely preserving the original pavement structure should be investigated.
The tasks include the following:
Benefits: Recommendations on the optimum application timing of restoration or rehabilitation treatments that will extend pavement service life or indefinitely preserve the original pavement structure and a tool for practicing engineers to use in designing long-life cost-effective concrete pavements with minimal restoration.
Products: Recommendations on the type, design, construction, and optimum application timing of restoration or rehabilitation treatments for extending pavements service life or indefinitely preserving the original pavement structure.
Implementation: This research will be coordinated closely with work in track 2. The research will provide a product needed to ensure that long-term preservation treatments are considered fully and available. This problem statement is linked to problem statement 7-4-1.
This subtrack addresses the materials, construction, and QA requirements unique to long-life concrete pavements and overlays. Table 52 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-3-1. Development of Quality Control/Quality Assurance Testing Standards to Ensure Long-Life Concrete Pavements | $500,000–$600,000 | QC/QA procedures for assessing the overall construction quality to determine whether the construction quality can achieve long life. | QC/QA guidelines that provide practicing engineers with the tools for ensuring that concrete pavements are constructed as designed, thereby reducing possible discrepancies in anticipated service life. |
9-3-2. Identification of Material Requirements and Tests for Long-Life Concrete Pavements | $1–$1.5 million | Material requirements and testing guidelines for establishing the suitability of long-life pavement materials for a wide variety of climates considering concrete, base, and other materials. | Reliable requirements and testing guidelines for identifying suitable concrete materials as well as base and other materials and tools for practicing engineers that will design against possible material-related problems and distress. |
9-3-3. Design, Construct, and Evaluate Experimental Long-Life Concrete Pavements | $3–$5 million | Design and construction of several promising concrete pavement types with appropriate design features, foundations, materials, construction, QC/QA, and preservation treatments, considering advancements from other research and development including precast joints and advanced materials, as well as pavements monitored for performance over time. | Design, construction, and monitoring of several promising concrete pavements that will prove the long-life pavement concept and strongly encourage implementation of other such long-life projects. |
9-3-4. Design, Construct, and Evaluate Concrete Overlays | $3–$5 million | Promising concrete overlay types with appropriate design features, surface characteristics, foundations, materials, construction, QC/QA, and preservation treatments. | An exceptionally strong long-life pavement with concrete overlay, combining the strengths of a solid concrete foundation with a renewable surface designed around functional requirements. |
This research will establish standards for QC/QA testing to ensure LTPP. The standard will specify the type of testing to be conducted, testing procedures, testing frequency, and reporting requirements. The acceptable construction tolerances will also be specified for key construction factors, including slab thickness, joint spacing, concrete strength, joint LTE, dowel bar alignment, tie-bar placement accuracy, and foundation uniformity and stability. Repairs may be permissible for certain deficiency types. In such cases, the acceptable repairs for the deficiencies also will be specified. A procedure for assessing the overall construction quality also will be developed to determine whether the construction quality can achieve long life.
The tasks include the following:
Benefits: QC/QA guidelines that provide practicing engineers with the tools for ensuring that concrete pavements are constructed as designed, thereby reducing possible discrepancies in anticipated service life.
Products: QC/QA procedure for assessing the overall construction quality to determine whether the construction quality can achieve long life.
Implementation: This research will ensure that long life concrete pavements are constructed with the appropriate quality and that no major construction problem will result in premature pavement failures.
Good material performance is essential for long-life pavement. Materials that must perform well include concrete, a base layer, a subbase layer, tie-bars, dowel bars, and deformed reinforcement. This research will document material problems that have caused premature pavement failures in the past, along with information about high-risk areas for such problems. A long design life may not be practical in some areas due to a high risk of developing material problems. If such limitations exist, identifying the high-risk areas and materials, as well as the practical design life limit, can optimize pavement design. However, the material problem can often be mitigated using various treatments and certain design features. This research will result in testing guidelines for identifying potential material problems as well as mitigation strategies.
The tasks include the following:
Benefits: Reliable requirements and testing guidelines for identifying suitable concrete materials as well as base and other materials and tools for practicing engineers that will design against possible material-related problems and distress.
Products: Materials requirements and testing guidelines for establishing the suitability of long-life pavement materials for a wide variety of climates, considering concrete, base, and other materials.
Implementation: This research will be coordinated closely with work in track 2. The results of this research are essential to reliable long-life concrete pavement designs, materials, and construction. Results will be immediately useful and will be used to design and construct the test sections under problem statement 9-3-3.
This research will develop innovative designs that promise superior long-term performance and test them in an ALF, test roads (e.g., MnROAD), or as a highway test section (e.g., LTPP). The designs may include innovative structural section, including concrete overlays; precast designs and advanced materials; and innovative pavement service life management that considers rehabilitation strategy as a part of life-cycle design. Based on the results of this research, the long-life pavement design guidelines developed under this research track may be modified.
The tasks include the following:
Benefits: Designing, constructing, and monitoring several promising concrete pavements that will prove the long-life pavement concept, strongly encouraging implementation of other such long-life projects.
Products: Design and construct several promising concrete pavement types with appropriate design features, foundations, materials, construction, QC/QA, and preservation treatments, considering advancements from other research and development including precast joints and advanced materials. Pavements that will be monitored for performance over time.
Implementation: This research will be coordinated closely with work in subtrack 9-4. Constructing the most promising designs will demonstrate the feasibility of long-term concrete pavement. Results from design, construction, and materials will be useful immediately to States. Performance will be useful over time.
Concrete overlays are discussed throughout the CP Road Map, especially in the problem statements addressing the use of asphalt bases throughout track 1. This problem statement will develop approaches to long-life pavements that consider concrete overlay construction principles during initial construction and over the analysis period. The research in this problem statement addresses JCPs or CRCPs over an asphalt base or subbase with a cement/epoxy-type or porous concrete surface. For all surface types, the surface is renewable, and the concrete slab is expected to require little maintenance or rehabilitation for 30–50 years or more.
The tasks include the following:
Benefits: An exceptionally strong long-life pavement with concrete overlay, combining the strengths of a solid concrete foundation with a renewable surface designed around functional requirements.
Products: Promising concrete overlay types with appropriate design features, surface characteristics, foundations, materials, construction, QC/QA, and preservation treatments.
Implementation: The research in this problem statement will be coordinated with work in subtrack 9-4. This research also will be integrated with SHRP 2 Renewal Project R21, Composite Pavement Systems, as it pertains to concrete overlays.(12) Results from the design, construction, and materials aspects of this research will be useful immediately to States, while performance data will be useful over time. This research also may be addressed in other tracks (i.e., tracks 2, 4, 6, and 8). This problem statement is linked to problem statement 8-3-4.
This subtrack addresses the full design of a new long-term data collection program for concrete pavements and integration with a concrete pavement rating system. This subtrack will provide the information necessary to support the modeling work identified in other tracks and the analysis of new experimental sections. Table 53 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-4-1. Identification of Accelerated and Long-Term Data Needs | $750,000–$1.5 million | A detailed plan outlining data needs to support research planned under the CP Road Map, consisting of both accelerated loading sections and long-term road tests. | An effective and productive research program for collecting data through ALFs and full-scale road tests in support of the CP Road Map. |
9-4-2. Concrete Pavement Data Management and Distribution | $800,000–$1.2 million | A comprehensive plan for a Web-based, easy-to-access, and easy-to-use system for collecting, evaluating, and distributing data that incorporates a mechanism for importing data from other databases, as well as reliable and accurate data for developing, calibrating, and validating tools required for pavement design, evaluation, rehabilitation, construction, etc., and a flexible system that allows data structure to be modified easily at any point. | Reliable and accurate data that pavement engineers can use to develop new tools or calibrate and validate existing tools or technology for pavement design, evaluation, rehabilitation, etc. |
9-4-3. Master Plan for Conducting Accelerated Testing of Products and Full-Scale Road Experiments | $900,000–$1.5 million | An overall master plan for conducting accelerated testing of products developed under the CP Road Map, detailing the effectiveness of using ALFs in fast-track pavement testing, identifying appropriate testing needs for ALFs and new approaches that might improve the ALF testing process, and determining ways in which ALFs might accomplish research needs, as well as a master plan for conducting full-scale long-term road tests of products developed under the CP Road Map. | A program to test, verify, and validate products developed under the CP Road Map, giving credibility and validity to many of the individual research efforts. |
9-4-4. Develop Experimental Designs and a Data Collection and Performance Monitoring Plan for Accelerated Loading Facilities and Full-Scale Products Testing | $800,000–$1.5 million | Experimental designs and a data collection and performance monitoring plan for ALF and full-scale road testing of products developed under this track, as well as four ALFs and four test roads. | Experimental design for testing products developed under this track using ALF or full-scale in-service pavements and materials, construction, design, traffic, and materials data collected from both ALF and full-scale testing that will provide many years of reliable pavement analysis data. |
9-4-5. Concrete Pavement Rating System for Highways | $200,000–$400,000 | Guidelines for State highway agencies to improve their pavement rating systems and implementation documents to be used directly by highway agencies to make use of high-speed highway pavement rating procedures. | A more accurate and efficient high-speed highway pavement rating system for use by State highway agencies. |
This research will identify data needs and existing data sources to support other research planned under the CP Road Map.
The tasks include the following:
Benefits: A detailed plan that provides an effective and productive research program for collecting data through ALFs and full-scale road tests in support of the CP Road Map.
Products: A detailed plan outlining data needs to support research planned under the CP Road Map consisting of both ALFs and long-term road tests.
Implementation: This research will be coordinated closely with work in tracks 2 and 6 and subtrack 9-3. The data needs identified in this research will be planned for and obtained throughout the CP Road Map.
This research will develop an initial comprehensive framework and a computerized database for collecting, evaluating, and distributing data. The system will be Web-based and user-friendly and should incorporate a mechanism that easily imports data from existing databases. The database will be organized by specific objectives (e.g., modeling of slab cracking, faulting, smoothness, noise, productivity, etc.) to streamline the data elements for any given objective. The system must also allow the data structure to be modified easily and flexibly at any point, letting users add or delete data elements and reorganize the data tables as needed. The system will provide raw data as well as processed results. The type and format of the processed results offered should be established in light of various user needs (e.g., FHWA, State highway agencies, contractors, researchers, material suppliers, equipment manufacturers, and trade organizations). The database will initially be populated by existing data from previous concrete pavement ALFs and road tests, but it will include input for data identified under problem statement 9-4-1. The database will expand as new testing data is obtained.
The tasks include the following:
Benefits: Reliable and accurate data that pavement engineers can use to develop new tools or calibrate and validate existing tools or technology for pavement design, evaluation, rehabilitation, etc.
Products: A comprehensive plan for a Web-based, easy-to-access, and easy-to-use system for collecting, evaluating, and distributing data that incorporates a mechanism for importing data from other databases. Reliable and accurate data for developing, calibrating, and validating tools required for pavement design, evaluation, rehabilitation, construction, etc. A flexible system that allows data structure to be modified easily at any point.
Implementation: The results of this research will be used in many research activities throughout the design track.
Several time-consuming factors (i.e., field trials and testing) are required to develop and launch an innovative idea or product successfully for concrete pavement design or construction. This is because the idea or product must be shown to improve current procedures genuinely in the short, intermediate, and long term and must be cost effective. For a concrete pavement structure, full-scale testing may include constructing in-service pavements that are subjected to both climate and traffic loads for more than 10 years. However, specific design aspects, such as transverse joints, could be tested more rapidly under an ALF.
Accelerated testing can significantly reduce the time needed to prove that an idea or a product is effective. This recently has been made possible by the development of several ALFs throughout the United States. ALFs can fast-track field testing and thus reduce the time between the development of an idea or concept and its implementation in the form of design guidelines or catalogues. However, ALFs do not always simulate field conditions entirely, and this shortcoming must be considered to determine whether ALFs can effectively obtain field performance data that assesses the usefulness of an innovative design. The following tasks will determine the effectiveness of using ALFs to fast-track pavement testing.
The tasks include the following:
Benefits: A program to test, verify, and validate products developed under the CP Road Map, giving credibility and validity to many of the individual research efforts.
Products: A master plan for conducting accelerated testing of products developed under the CP Road Map, detailing the effectiveness of using ALFs in fast-track pavement testing, identifying appropriate testing needs for ALFs and new approaches that might improve the ALF testing process, and determining ways in which ALFs might accomplish research needs, as well as a master plan for conducting full-scale long-term road tests of products developed under the CP Road Map.
Implementation: This research will be coordinated closely with work in tracks 2 and 6 and subtrack 9-3. The data needs identified in this research will be planned for and obtained throughout the CP Road Map.
Each ALF and full-scale road testing experiment conducted under this track will require experimental designs. Well-designed experiments will maximize information while minimizing costs and offer the greatest chance for achieving reliable results. Each ALF and full-scale road testing experiment will require a data collection and performance monitoring plan to test products developed under this research. The research in this problem statement should account for experiments studying a range of traffic loadings from low- to high-traffic volume roadways as well as experiments that address accelerated durability testing for concrete paving materials and design.
For each experiment conducted, the following tasks must be done as a minimum:
Benefits: Experimental design for testing products developed under this track using ALF or
full-scale, in-service pavements, as well as materials, construction, design, traffic, and materials data collected from both ALF and full-scale testing that will provide many years of reliable pavement analysis data.
Products: Experimental designs and a data collection and performance monitoring plan for ALF and full-scale road testing of products developed under this track, as well as four ALFs and four test roads.
Implementation: This research will be coordinated closely with work in tracks 2 and 6 and subtrack 9-3. The data needs identified in this research will be planned for and obtained throughout the CP Road Map.
State highway agencies use many procedures to rate their pavements for management and engineering purposes. These vary widely from State to State. This research will develop guidelines for State highway agencies to improve their pavement rating systems.
The pavement condition index (PCI) procedure was developed in the 1970s and 1980s for airport pavements and city street pavements. The main scope of PCI was to provide a simple yet consistent tool for rating pavements that would reflect the experience of many experienced engineers. The rating scale, from zero to 100, was divided into categories such as excellent, very good, good, fair, poor, and very poor. This procedure found wide use and acceptance by the U.S. military, Federal Aviation Administration (FAA), and some cities. Its main advantage is that it provides a simple, consistent, and uniform way to rate pavements with an overall score, but it also includes individual distresses to determine the causes of deterioration, making it possible to better recommend rehabilitation treatments. In the 1980s, FHWA sponsored research to adapt the PCI to high-speed highways, and an initial procedure was completed. This initial work needs further consideration regarding its value today for State highway agencies as a consistent rating procedure.
The tasks include the following:
Benefits: A more accurate and efficient high-speed highway pavement rating system for use by State highway agencies.
Products: Guidelines for State highway agencies to improve their pavement rating systems and implementation documents to be used directly by highway agencies to make use of high-speed highway pavement rating procedures.
Implementation: This work will result in implementation documents to be used directly by highway agencies to use the PCI procedures for high-speed highways.
This subtrack addresses the preparation of concrete pavement data collection and testing procedures and the construction of accelerated loading sections and test road sections. Table 54 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-5-1. Preparation of Concrete Pavement Data Collection and Testing Procedures | $500,000– $1 million |
Development of data collection, testing procedures, protocols, as well as laboratory, ALF, and full-scale testing specifications for projects developed under problem statement 9-5-2. | Adoption of existing or development of new and more reliable test protocols for use in the pavement performance experiments. |
9-5-2. Construction of Accelerated Loading Sections and Test Road Sections | $4.8– $7.2 million |
Execution of experimental plans developed under previous tasks, including the establishment of experimental test sections, a materials testing program, and performance monitoring to obtain data for developing pavement analysis and tools, as well as data stored in the database developed under problem statement 9-4-4 that will be used for calibration, validation, and other activities for the pavement performance models used in the CP Road Map. | Available construction, design, traffic, and materials data collected from both ALFs and full-scale testing for pavement analysis. |
Because consistent and calibrated testing is critical to the success of all research in this track, substantial efforts must be mobilized to achieve this goal. The research in this problem statement will adopt existing or develop new standard data collection and testing procedures and specifications for laboratory, ALFs, and test road experimental sections. The plan will specify the testing to be conducted for each data element identified in previous problem statements.
The tasks include the following:
Benefits: Adoption of existing or development of new and more reliable test protocols for use in the pavement performance experiments.
Products: Development of data collection, testing procedures, protocols, as well as laboratory, ALF, and full-scale testing specifications for projects developed under problem statement 9-5-2.
Implementation: The results of this research will be used in many research activities throughout the design track.
This task will execute the experimental plans developed under problem statements 9-4-4 and 9-5-1. An expert panel consisting of State highway agencies, FHWA, academia, industry representatives, and consultants will prioritize different experiments and set schedules. To the extent practical, standard procedure will be established and followed in documenting the attributes of the as-built experimental section, and standard protocol will be followed in monitoring and reporting performance.
The tasks include the following:
Benefits: Available construction, design, traffic, and materials data collected from both ALFs and full-scale testing for pavement analysis.
Products: Execution of experimental plans developed under previous tasks, including the establishment of experimental test sections, a materials testing program, and performance monitoring to obtain data for developing pavement analysis and tools. Data stored in the database developed under problem statement 9-4-4 that will be used for calibration, validation, and other activities for the pavement performance models used in the CP Road Map.
Implementation: This research will be coordinated closely with work in tracks 2 and 6 and subtrack 9-3. The data needs identified in this research will be planned for and obtained throughout the CP Road Map. These results will also be immediately used in calibration, validation, and other activities for models and engineering procedures developed in various research projects conducted under the CP Road Map.
Note: Assume four to six ALFs and four to six test roads will be constructed and tested each at approximately $600,000. Some funds from the private sector may be available ($1 million). These costs include engineering, testing, instrumentation, weather stations, construction, QC/QA, and monitoring, but not actual construction costs except for ALFs. For economy or expediency, any of these experimental test sites could be adjacent to asphalt test roads.This subtrack provides for the implementation of the long-life pavement research developed in the track, including accelerated loading and long-term data collection. Table 55 provides an overview of this subtrack.
Problem Statement | Estimated Cost | Products | Benefits |
9-6-1. Implementation of Long-Life Concrete Pavements | $800,000–$1.2 million | Strong transfer of long-life concrete pavement design and construction technology to the workforce using workshops, conferences, and Web-based personnel training. | A knowledgeable workforce and management that can use the design procedure to design, construct, and specify materials and preserve long-life concrete pavements properly when long-life designs are required. |
9-6-2. Implementation of Accelerated Loading and Long-Term Data Collection | $800,000–$1.2 million | Immediate transfer of results from the accelerated or long-term test facilities to researchers working on the overall concrete pavement research plan, using various research contracts conducting the work, the Internet, and summary reports presented at onsite workshops and conferences, as well as constructing, testing, and monitoring several experimental ALFs and full-scale road test sections, producing unbiased results that are useful for calibrating, validating, and developing various key prediction models in the CP Road Map. | Field-proven performance data that theory has predicted, important for calibrating and validating studies for the various models and predictions developed under the CP Road Map. |
Implementing long-life concrete pavement requires significant efforts in both training the workforce and convincing management that long-life concrete pavement is feasible and reliable. This task addresses both of these efforts. The results from many other tracks and projects will help develop long-life pavements, and these other efforts will be used in this task without being repeated. For example, track 2 offers a design procedure that is fully capable of designing long-life pavements. However, additional design work will be needed to ensure a reliable design.
The tasks include the following:
Benefits: A knowledgeable workforce and management that can use the design procedure to design, construct, specify materials, and preserve long-life concrete pavements properly when long-life designs are required.
Products: Strong transfer of long-life concrete pavement design and construction technology to the workforce using workshops, conferences, and Web-based personnel training.
Implementation: This work will provide the technology transfer critical to the success of the long-life concrete pavement track.
Implementing the accelerated loading and long-term data collection advancements developed in this track will support many projects in the CP Road Map. The project research team will work extensively with contractors from other projects that need either accelerated or long-term performance data to ensure that the data needed is obtained properly.
The tasks include the following:
Benefits: Field-proven performance data that theory has predicted, which is important for calibrating and validating studies for the various models and predictions developed under the CP Road Map.
Products: Immediate transfer of results from the accelerated or long-term test facilities to researchers working on the overall concrete pavement research plan, using various research contracts conducting the work, the Internet, and summary reports presented at onsite workshops and conferences. Constructing, testing, and monitoring several experimental ALFs and full-scale road test sections, producing unbiased results that are useful for calibrating, validating, and developing various key prediction models in the CP Road Map.
Implementation: This work will provide the technology transfer critical to the success of track 9.