Performance Specifications for Rapid Highway Renewal (2014)

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44 C h a p t e r 4 A review of the information gathered during the R07 research effort—including findings from the literature review, practi- tioner input, and analysis of case studies and demonstration projects—shows that performance specifications can increase quality, encourage innovation, promote the use of new mate- rials and technology, and reduce an agency’s quality assur- ance burden during construction. To achieve these benefits, performance specifications should emphasize desired out- comes (either through as-constructed end-result require- ments or target levels of service over some defined period of performance) while eliminating unnecessary constraints on materials selection and construction methods. The successful implementation of performance specifications requires care- ful project selection and institutional support. Success also depends on following systematic approach to specification development. research products The R07 team recognized that guidance is needed for decision makers and project managers to properly implement per- formance specifications at the program or project level, and for engineers and specifiers to develop performance spec- ifications for any type of application. Therefore, the team developed guide performance specifications and associated implementation guidelines to help support the application of performance specifications across a wide range of work and projects. Guide Performance Specifications To help agencies develop and implement performance speci- fications, the R07 team drafted a set of AASHTO-formatted guide specifications to be used by engineers and specifiers as a template from which to develop project-specific performance specifications for various topic areas. Guide performance specifications are provided in the areas of HMA and PCC pavement, concrete bridge decks, geotechnical application areas, work zone traffic control, and quality management. The specifications include commentary to help specifiers select performance parameters and performance measure- ment strategies (test methods, sampling plans, target values, pay adjustment mechanisms) that best align with the proj- ect’s goals and the capabilities of the agency and local indus- try. Emphasis is placed on the use—to the extent possible—of new and emerging nondestructive testing (NDT) techniques which facilitate rapid renewal and performance parameters that validate mechanistic models used for design. As applicable, the guide specifications have been tailored to specific delivery approaches (design-bid-build, design-build, warranty, and design-build-operate-maintain). The chosen approach can significantly affect how much performance risk can be placed on the private sector. Thus the team factored in both possible changes to traditional roles and responsibilities with respect to design, quality management, and postcon- struction maintenance, and the level at which performance parameters may be set. If properly implemented, the guide specifications will pro- vide agencies with a useful tool to motivate and empower the private sector to offer innovative solutions to save time, mini- mize disruption, and achieve long life in the interest of rapid renewal for these specific applications. The audience for the guide specifications includes design, construction, materials, and maintenance personnel from within a state or local highway agency, and industry partners including consultants, researchers, industry advisory mem- bers, and reference standard organizations. Implementation Guidelines To accompany the guide specifications, the team also prepared a two-volume set of implementation guidelines. Strategies for Implementing Performance Specifications: Guide for Executives and Project Managers provides a broad overview Summary and Conclusions

45 of the benefits and challenges associated with implementing performance specifications. Recommendations address proj- ect selection criteria, procurement and project delivery options, industry and legal considerations, and the various cultural and organizational changes needed to support the implementation of performance specifications. The audience for the strategies guidelines includes mid- level to senior managers and project engineers within state or local highway agencies and industry partners such as contrac- tors, subcontractors, and material suppliers. The anticipated benefits of the strategies guide are as follows: • Improved decision making by executives and project man- agers leading to more effective implementation of perfor- mance specifications and a more performance-oriented business model; and • Improved understanding of the changes in risk allocation and contract administration associated with different proj- ect delivery methods. Framework for Developing Performance Specifications: Guide for Specification Writers presents a flexible framework for assess- ing whether performance specifying is a viable option for a par- ticular project or project element. When applicable, this volume explains how performance specifications can be developed and used to achieve project-specific goals and satisfy user needs. The guidance is intended to be accessible to both experienced and novice members of a project team, as well as adaptable to any project element and delivery method. In addition to providing a step-by-step “how-to” guide for developing performance specifications, the document also contains guidance on specific application areas (e.g., pave- ments, bridge decks, earthworks, and work zone) found to have the greatest need or potential for performance specifying. Demonstration projects An important step in implementing performance specifica- tions is to demonstrate their viability on actual projects, by collecting data to measure and evaluate performance against traditional specifications and using the lessons learned to make improvements and support continued implementation. For example, an important objective is to move beyond the use of specification acceptance properties that act only as sur- rogates for performance to the use of measures that more directly correlate with performance and the assumptions in the design process. Demonstrating the new specifications pro- vides a means to begin the move toward more performance- oriented requirements. The team completed two projects, the Missouri DOT Route 141 Roadway Improvement Project, dem- onstrating the use of roller-integrated compaction monitoring (RICM) technology for improved compaction of the roadway foundation, and the Virginia DOT Lake Anna Bridge Reha- bilitation Project, demonstrating the use of acceptance prop- erties that place more emphasis on durability. Missouri DOT Route 141 Roadway Improvement Project—Geotechnical Performance Specifications As part of the development of the geotechnical performance specification for earthworks, a field project was conducted in partnership with Missouri DOT in the fall of 2010 and 2011 on Route 141 in Chesterfield, Missouri. The project involved working with Missouri DOT, the contractor (Fred Weber, Inc.), and an equipment provider (Caterpillar Inc.) to demonstrate earthwork QC/QA performance measurement technologies, including RICM technology, in combination with mechanistic- related QA testing methods (plate load tests, dynamic cone penetration tests, and borehole shear tests). The results of the field-testing phase of the project were used to evaluate the proposed earthwork performance and proof mapping specifications, which are included in Appendix C. One of the key attributes of the proposed specifications was the use of mechanistic-based performance measurements and the geospatially referenced RICM data. This approach eliminates traditional moisture/density testing with a nuclear gauge and requires the contractor to field control the operation around performance design values. Some of the important findings from the research work on the Missouri DOT project include the following: • Traditional nuclear density testing results are not necessar- ily repeatable between the QC and QA agents. Further, the RICM MVs are not well correlated to percent relative com- paction or moisture content. • Alternative in situ testing methods—including plate load testing, light weight deflectometer testing, and dynamic cone penetration testing—provide quality measurements of support conditions. • Final acceptable procedures based on proof rolling with a loaded dump truck can be replaced with RICM proof map- ping. Using RICM eliminates the need to use loaded trucks, provides integrated measurements, and is faster with greater coverage. • Challenges remain with implementation of RICM and alternative testing methods because of the lack of training and accepted test methods and standards. Virginia DOT Route 208 Lake Anna Bridge Rehabilitation Project The Virginia DOT project demonstrated a performance shadow specification for a hydraulic cement concrete bridge

46 deck using construction parameters that relate to perfor- mance (e.g., PCC deck permeability, cracking, joint condi- tion, skid, smoothness, and thickness and cover depth). A PWL was developed for construction parameters (e.g., cover depth, thickness, strength, and permeability), and pass–fail criteria were used for other parameters (e.g., cracking, joint condition, and cross-slope). The performance specification was shadowed to compare results with Virginia DOT’s end- result specification, which incorporates a PWL with pay adjustments for strength and permeability. Compared with the Virginia DOT specification, the pay factors for the R07 performance specification would have resulted in a more severe penalty for certain parameters (e.g., cover depth and thickness) and a higher bonus for others (e.g., strength and air content). An important consideration is that agencies will need to carefully set limits for parameters and use pay adjustment formulas that balance targeted per- formance with what industry can reasonably achieve. Another important lesson learned from this demonstration project was that workmanship issues can have a large effect on performance outcomes, and such issues may not necessarily be addressed or identified through the use of performance parameters measured through end-result testing. Given this result, the team developed a checklist, included in Appendix F, for use as a companion document with the guide specifica- tion. The checklist addresses inspector certification, transpor- tation and handling, preplacement and placement inspection, and postplacement inspection. Louisiana DOTD US-90 Frontage Roads The team advised LTRC on the development of a research plan and draft specifications to evaluate the use of non- destructive roller-integrated compaction monitoring (RICM) and mechanistic-based in situ point measurements on a new pavement section, including subgrade, stabilized subgrade, base course, and HMA layers. The Louisiana DOTD and LTRC are moving forward with a demonstration project with the following goals: • Demonstrate the value of real-time quality control of com- paction operations to accelerate construction, reduce rework, and improve uniformity; • Improve the value of field data and reduce the frequency of traditional sampling through improved construction pro- cess control; • Evaluate the reliability and potential use of RICM data for acceptance and measurements of in situ stiffness of the constructed earth materials, and link properties that relate more directly to design (e.g., modulus) and in-service performance; • Establish the value of using RICM and mechanistic-based point measurement technologies for rapid renewal projects by benchmarking against sections built using standard con- struction techniques; and • Establish long-term monitoring sections and monitoring protocols/assessments for LTRC to document the value of implementing this specification approach and technologies. LTRC began collecting performance data for the earthwork operations in December 2012. Additionally, North Carolina State University, under FHWA Project DTFH61-08-H-00005, plans to collect HMA materials from this project during con- struction and characterize them with the mechanistic-based tests (e.g., S-VECD) being developed under the FHWA con- tract. Louisiana DOTD and LTRC are also planning to test the materials and perform long-term monitoring of the project. This supplemental work will enhance the future validation of performance specifications as advances are made in testing. recommendations for Future activities and Implementation The team has identified a number of potential follow-on activ- ities that would help move the products of this research effort into practice. These activities can be classified into four gen- eral areas: future demonstration projects, continued specifi- cation development, training and outreach, and development of automated tools for specification development. Demonstration Projects Demonstration projects are a proven tool for validating and fine-tuning new procedures, specifications, and contracting practices resulting from research. The validation process typ- ically involves benchmarking by comparing the outcomes of projects using traditional procedures with the performance of projects using the new practices to determine the relative success. The team reached out to a number of agencies during the project to explore the possibility of conducting demonstra- tions. Agencies expressed a high level of interest in demon- strating performance specifications. For example, 10 agencies (Caltrans, Missouri DOT, Louisiana DOTD, Virginia DOT, Pennsylvania DOT, Florida DOT, South Carolina DOT, Wis- consin DOT, Utah DOT, and Delaware DOT) explored with the team the potential for implementing performance speci- fications on a suitable demonstration project. Given the R07 budget and schedule, the team decided to move forward with three demonstration projects (Missouri DOT, Virginia DOT, and Louisiana DOTD). However, the team believes that sig- nificant opportunities for additional demonstrations exist.

47 Performance specifications could be further validated by conducting long-term, postconstruction performance moni- toring to assess their relative value. Particularly useful would be demonstrations of the long-term performance outcomes for warranty and DBOM specifications using postconstruc- tion performance parameters. Suitable project types for this scenario would likely involve pavement applications but could also include bridge or structural elements for which long-term performance evaluations (i.e., health monitoring) would be necessary to assess value. Continued Performance Specification Development and Implementation Before initiating the SHRP 2 R07 project, FHWA convened an expert technical group (ETG) with representatives from AAS- HTO, industry, and academia to provide guidance and support for the continued development of performance specifications, with particular focus on PRS for rigid and flexible pavements. With the issuance of draft performance guide specifications and implementation guidelines under SHRP 2 R07, the team sees a need to reestablish a performance specification ETG to provide continued support and guidance for implementation of the performance specifications developed under the R07 project and to identify additional performance specifications to test and implement. The ETG’s activities could potentially cover several areas. The ETG’s primary activity would be to assist with the adoption of selected R07 specifications as AASHTO guide specifications by providing additional vetting of the specifi- cations and acting as liaisons to the relevant AASHTO sub- committees. The ETG could also help build the business case and institutional support for the use of performance specifi- cations. That would involve fostering a performance-based culture within owner organizations, handling legal issues, addressing industry concerns (i.e., risk management, insur- ance and bonding, and subcontractor relationships), and also addressing project delivery and procurement considerations. In the area of pavements, the ETG could further develop and demonstrate test methods and acceptance criteria using NDT that more directly relate to performance (e.g., mechanistic- based properties) and could support PRS demonstrations (e.g., FHWA-sponsored research and demonstrations using Pave- Spec for PCC and HMA predictive models). For bridges, the ETG could develop performance specifications for additional elements (e.g., piers, beams, or whole bridge performance), develop performance criteria for field acceptance of modular bridge components or innovative bridge technology (e.g., fiber- reinforced polymer composite bridges), and monitor systems for long-term performance of technological advancements and data management. For geotechnical applications, the ETG could develop additional performance specifications for ground improve- ment and pavement foundations, develop and test accep- tance criteria for RICM on the basis of mechanistic properties (e.g., modulus), and integrate geotechnical and pavement performance specifications. In the area of work zone traffic control, the ETG could support the advancement of tools for monitoring performance, the standardization of methods for calculating incentives and disincentives, and the manage- ment of data and independent verification of data. The ETG could also take the lead on development of performance specifications for other highway construction elements (e.g., lighting, signals, signage, pavement markings, guardrails, and landscaping). And finally, the ETG could provide training and outreach to stakeholders at AASHTO, FHWA, local agen- cies, and industry partners. Training and Outreach As part of a short-term implementation strategy, the products of this research effort can be effectively broadcast to stake- holders through a series of webinars, supplemented by articles and presentations at highway industry forums. For example, a potential topic area for project managers may include “Decid- ing When to Use Performance Specifications,” which could address project selection criteria, delivery and procurement considerations, risk allocation, contract administration, and other management considerations related to the use of per- formance specifications. A potential webinar for specification writers could address the step-by-step process for drafting performance specifications, which could be further tailored to a specific project type or element (e.g., pavement, bridge deck replacement, work zone traffic). Longer-term outreach activities could entail developing materials for 1-day or 2-day workshops or more formalized training programs sponsored by the National Highway Insti- tute, the FHWA Resource Center, state highway agencies, university-affiliated transportation institutes, or other forums. For example, the National Highway Institute presents a con- struction course titled, “Principles of Writing Highway Con- struction Specifications.” Module 4 of the course addresses approaches to writing end-result specifications. This mod- ule could be updated to include the SHRP 2 R07 guidance for drafting performance specifications. Additional topics for formal training could include specific PRS training for pavements. Web-Based Specification Development Tool The team believes that the development of an electronic tool to help specifiers write performance specifications for specific applications would have significant value. This approach is

48 consistent with current agency trends toward developing and maintaining web-based specifications. The tool would gener- ally be based on the guide for specification writers and could be database-driven with standard language and templates for different types of product specifications. The tool would guide the specification writer through steps or decision points with various options to consider depending on the project scope and characteristics. On a very high level, these steps may include the following: 1. Identifying project scope and characteristics; 2. Defining project goals; 3. Assessing whether goals can best be achieved through use of performance or method specifications; 4. Selecting the appropriate project delivery approach aligned with project goals and risk allocation; 5. Assessing which performance parameters to use and how to measure and test them to manage performance; 6. Selecting appropriate template language from a database or e-library of performance guide specifications on the basis of delivery method; and 7. Adapting the specification to the specific project on the basis of guidance and options for roles and responsibili- ties, testing, verification and acceptance, and payment system. The level of effort needed to develop this tool would depend in part on the product areas and types of performance spec- ifications considered in the tool. One possible approach would be to develop the tool incrementally, focusing on a specific product area (e.g., pavements) and developing a beta version for testing. The beta version should also be compat- ible or work in conjunction with other web-based specifi- cation development tools, for example, SpecRisk Quality Assurance Specification Development and PaveSpec soft- ware tools.