The Superpave Mix Design System: Anatomy of a Research Program (2012) / Chapter Skim
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Pages 97-158
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From page 97... ...
95 CHAPTER 5. IMPLEMENTATION PHASE This chapter summarizes the efforts to implement the results and products developed during the research phase of the program.
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From page 98... ...
96 SHRP Chairman John Tabb also encouraged attendees to start thinking about implementation. He said, "We are counting on you to start the implementation effort here and now by going back home to champion the emerging products of SHRP within your own agencies." He also recognized that implementation is a major effort, requiring "money, effort, time and patience." He likened SHRP implementation to the advent of personal computing.
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From page 99... ...
97 5.2 TRANSITION TO IMPLEMENTATION Although the seeds of implementation had been sown earlier during the research phase, implementation planning activities increased markedly as the research phase drew to a close. During 1992, the groundwork was laid for the later implementation efforts in the SHRP offices and at FHWA.
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98 Table 11 Detailed Steps in the SHRP Program Office Implementation Plan (After Kulash, 1992)
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99 Ultimately, this boiled down to three major concerns about SHRP implementation: 1. The gap between management and materials 2.
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100 5.2.2 Transition to Implementation at FHWA While it is well-documented that FHWA did not play a lead role during the research phase, it was assumed that FHWA would be playing a role in the implementation of the research. Heretofore, the only major roles played by FHWA were Executive Director Dean Carlson sitting on the Executive Committee and FHWA Loaned Staffers Dick McComb and Paul Teng.
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From page 103... ...
101 5.2.2.1 1992-93 Implementation – FHWA Timeline One key element of managing the program was the establishment of a formal timeline to achieve acceptance of the binder and mix specifications and tests as standard practice. FHWA developed a timeline, shown in Figure 39, to guide implementation efforts.
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From page 104... ...
102 Figure 39 FHWA April 1992 Timeline for Superpave Implementation The implementation plan for Superpave that was eventually developed called for the following activities and organizations: Pooled-Fund Equipment Purchase TE19 Technical Assistance Program National Asphalt Training Center (NATC) DP90 Mobile Asphalt Lab Program In addition to these activities, other groups and efforts also played a role, as will be discussed in Section 5.4.
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From page 105... ...
103 5.2.2.2 Pooled-Fund Equipment Buy Program (1992-93) One of the first major efforts of the FHWA Implementation Program was the acceptance of a pooled-fund study that would procure sets of binder and mix equipment for each state DOT.
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From page 106... ...
104 rigorous testing followed by the manufacture and shipment of the approved equipment," remembered D'Angelo. 5.2.2.3 Superpave Loaner Equipment (1992)
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From page 107... ...
105 1) the FHWA could transition to Superpave or AAMAS, and 2)
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From page 108... ...
106 implementation approaches. The key to the entire implementation program was this line item for SHRP implementation at the level of $50M, in addition to FHWA's normal technology development funds.
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From page 109... ...
107 In this plan, the goals of the implementation process were defined as well (18) : To fully and professionally communicate final SHRP research findings to the US highway community.
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From page 110... ...
108 academia are kept informed of implementation efforts and issues. This internal FHWA group coordinated activities as appropriate with other interested groups, including the TRB-SHRP committee.
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From page 111... ...
109 technical area. While a significant element of the assignment was to coordinate the flow of information, the need for more technical involvement was paramount in order to make the transfer timely and effective.
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110 5.4 KEY GROUPS AND ACTIVITIES FOR IMPLEMENTATION Under FHWA during the first phase of implementation, several groups became active in the Superpave implementation efforts – some were spins offs of existing organizations and others were new entities developed specifically to participate in Superpave implementation. Most of these groups and activities are still in existence though they have adapted to changes in the status of implementation.
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From page 113... ...
111 problems can be the death knell for the product. Those early users get a bad taste in their mouths and may not be willing to try a second time.
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112 Table 12 Members of AASHTO Task Force on SHRP Implementation Member Representing Joe Mickes (1996-97) Missouri DOT Bob Templeton (1996-97)
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113 Subcommittees under SCOH include Design, Construction, Materials, the Technology Implementation Group (TIG) and more.
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114 Faster implementation, giving states the benefit of earlier cost savings, and Better understanding of the technology and end results. In June 1996, Task Force Chairman Templeton wrote to six states inviting them to assume the role of Lead States for Superpave implementation.
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115 Jim Warren Florida Industry Rick Smutzer (later David Andrewski) Indiana DOT Gerald Huber Indiana Industry Rebecca McDaniel Indiana Superpave Center Lee Gallivan Indiana FHWA, IN Division Larry Michael Maryland DOT Jim Dunne Maryland FHWA, Region 3 Jitesh Parikh Maryland FHWA Maghsoud Tahmoressi Texas DOT Erv Dukatz Texas Industry Gary White Texas FHWA, TX Division Wade Betenson Utah AASHTO SCOH Liaison Cameron Peterson Utah DOT Gerald Barrett Utah DOT Mike Worischeck Utah Industry Tim O'Connell Utah Industry Tom Harman FHWA HQ Technical Resource Gary Henderson FHWA HQ Superpave Delivery Team Jeanne Fuchs Missouri Facilitator Martin Delaney (1999)
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From page 118... ...
116 Table 14 Superpave Lead State Team Goals and Strategies Goal Strategies 1. Develop local state pool of technically experienced people to assist with pilot projects in design, construction, and trouble shooting by January 1997 a.
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From page 119... ...
117 Binder testing services. The Lead State Team continued meeting in St.
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118 • Recommended high-priority research topics to FHWA and the Mixture Expert Task Group including reevaluating Ndesign, investigating the need for different VMA values for fine and coarse aggregates, and addressing field construction concerns. • Established a Lead State website for dissemination of information.
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From page 121... ...
119 5.4.2.1 Lead State Guidance The Lead States periodically released guidance, formally and informally, to assist states and industry. One of the main documents was released in June 1998 following a March meeting in Orlando with FHWA and a number of states.
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From page 122... ...
120 specifications had been fully implemented by 25 states and 15 additional states had implementation plans in place. Figure 40 Superpave Projects Awarded and Planned (in 2000)
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From page 123... ...
121 Expert advice Expert user support Long-range plan for research Standards adoption Visibility Communication Coordination State-of-the-art implementation Technology transfer and training Universal implementation Recommendations were made in each of the areas above for what needed to be done and what organization should assume responsibility for ensuring completion. The details are probably not important here, but the fact that plans were made to continue the effort is.
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From page 124... ...
122 5.4.3 Superpave Centers One might think that the concept of Superpave Centers was driven in large part by the idea of implementing FHWA's organizational ideas of regional and local management of SHRP and Superpave efforts. That was in the background, but one of the keys was the troublesome process of procuring SSTs and IDTs.
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From page 126... ...
124 is not to say the other Centers were not successful – they all were in their own ways – but the Centers that had strong regional support also had greater longevity and visibility. Each Center developed its own strengths in response to the needs of its region.
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From page 127... ...
125 Figure 41 Principals of the Five Superpave Centers meeting at the Asphalt Institute, circa 1996. (L to R, David Anderson, Northeastern; Jon Epps, Western; Rebecca McDaniel, North Central; Ray Brown, Southeastern; Bob McGennis, South Central)
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From page 128... ...
126 A 1997 AASHTO resolution (22) aimed to strengthen the support for the regional Centers.
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From page 129... ...
127 For each of the high-priority research projects, the group provided details of the problem, proposed research, potential benefit to highway agencies, as well as estimates of funding and time required to conduct the research. In addition to the high-priority research needs, the group identified and classified as highly important an additional research project entitled Refinement of Binder and Mix Tests, Specifications and Models, with funding to be provided by the FHWA.
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From page 130... ...
128 producer group in the Midwest. The invitees included representatives of the Indiana, Iowa and Minnesota DOTs and asphalt paving associations plus Dick Ingberg, the SHRP Regional contractor.
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From page 131... ...
129 To this day, the meetings are generally structured to provide information about what is happening in the asphalt arena on the national, regional and state levels. These meetings are one of a very few opportunities to learn about regional issues and solutions.
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From page 132... ...
130 A National Asphalt User-Producer Group was also active for several years. Its first meeting was held in Minneapolis in August 1993.
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From page 133... ...
131 Many of these QA contractors had recently built laboratories and now were being asked to discard their Marshall hammers, which cost $1200, and replace them with a gyratory compactor, estimated to cost $16,000. And since there was generally one laboratory at each hot-mix plant, the cost of implementation just for Level 1 mix design was considered excessive.
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From page 134... ...
132 Place Date 1 Atlanta, GA Jun 24 & 25, 1993 2 St Paul, MN May 26 & 27, 1994 3 Lexington, KY (Asphalt Institute) Aug 24 & 25, 1994 4 Austin, TX Feb 7 & 8, 1995 5 Reno, NV May 16 & 17, 1995 6 Baltimore, MD Sep 19 & 20, 1995 7 Phoenix, AZ Mar 4 & 5, 1996 8 Seattle, WA Sep 10 & 11, 1996 9 San Antonio, TX Mar 4 & 5, 1997 10 Colorado Springs, CO Sep 22 & 23, 1997 11 Orlando, FL Mar 10 & 11, 1998 12 Baltimore, MD Sep 22 & 23, 1998 13 Phoenix, AZ Mar 18 & 19, 1999 14 Washington, DC Sep 21 & 22, 1999 15 Washington, DC Mar 28 & 29, 2000 16 Indianapolis, IN Sep 11 & 12, 2000 17 Phoenix, AZ Apr 3 & 4, 2001 18 Washington, DC Aug 28 & 29, 2001 19 Denver, CO Feb 20 & 21, 2002 20 Minneapolis, MN Aug 28 & 29, 2002 21 Las Vegas, NV Sep 16, 17 & 18, 2003 22 Washington, DC Feb 11, 12 & 13, 2004 23 Washington, DC Sep 27 & 28, 2004 24 Madison, WI Jul 20 & 21, 2005 25 Denver, CO May 11 & 12, 2006 26 Crystal City, VA Sep 25 & 26, 2006 27 Denver, CO Jul 24 & 25, 2007 28 Tampa, FL Feb 25 & 26, 2008 29 Irvine, CA (Beckman Center)
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From page 135... ...
133 Similarly, the Asphalt Binder ETG dealt with issues regarding the asphalt binder specification. For example, the original SHRP research recommended the use of direct tension testing for the grading of modified asphalt binders.
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From page 136... ...
134 • Tender zone – mix could not be compacted because it is tender. • VMA – Superpave mixtures could not be designed with our aggregates to meet VMA requirements.
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From page 137... ...
135 apprehension in the industry. There were inevitable cost impacts associated with implementing Superpave that industry would have to bear – and pass along to their customers.
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From page 138... ...
136 with a corporate vision to be leaders and innovators also had a leg up. Good relationships – partnerships – between agencies and industry also helped overcome the reluctance to change.
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From page 139... ...
137 constructed a total of three pilot SPS-9 projects.) Each site consisted of multiple test sections to allow comparison of the existing state practice to Superpave.
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From page 140... ...
138 Availability of Superpave testing equipment has also increased greatly since the implementation phase began. In some cases, this equipment has been provided by industry to ensure that engineers graduating from those schools have the opportunity to become familiar with the technology they will be expected to use in practice.
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From page 141... ...
139 Continuing in 1996 until 2000 biannual workshops were sponsored by FHWA, with various co-sponsors including the Asphalt Institute, TRB, state DOTs, the Superpave Centers and other industry groups. The themes and locations of the workshops are shown below.
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From page 142... ...
140 offered. Sessions dealt with mix design, material selection, construction, and performance testing and modeling.
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From page 143... ...
141 5.5 IMPLEMENTATION AT RISK – THE TEA-21 YEARS In 1999, the Superpave world was about to change and very few people saw it coming. It started with the Transportation Equity Act for the 21st Century (TEA-21)
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From page 144... ...
142 Sort through complex Superpave performance-related tests and prediction methods to identify a "simple" procedure that could be used to confirm design values, and guide quality control and quality assurance; Validate the Superpave procedures and specifications by looking back at some Superpave mixes that had up to five years of field service; Assure that specification parameters and tolerances are set so that cost-effectiveness and product quality are maintained at an appropriate balance. In this far-reaching resolution (23)
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From page 145... ...
143 Table 17 Members of the TRB Superpave Committee Name Organization Joseph A Mickes, Chair Missouri DOT David Anderson Pennsylvania State University Martin F
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144 AASHTO's Standing Committee on Research (SCOR) reviewed in detail the Committee's slate of projects and recommended funding.
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From page 147... ...
145 The Superpave development and deployment program was moving forward with the support and participation of AASHTO, FHWA, the individual state DOTs, and the hot-mix paving industry; Mechanisms to monitor and coordinate Superpave and related hot-mix asphalt research had been established; and An effective long-range financial and technical plan for completion of Superpave implementation and deployment was under development. In many respects, 1999 was a landmark year.
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From page 148... ...
146 Goal 3. Superpave will integrate the binder and mix requirements into a performancebased construction quality control specification system Goal 4.
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From page 149... ...
147 completed NCHRP project (9-22, Beta Testing and Validation of HMA Performance-Related Specifications) developed software derived from the MEPDG to allow these comparisons and develop pay factors based on the anticipated pavement life compared to the design life.
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From page 150... ...
148 5.6.1 Binder Testing and Specifications There had been approximately 15 versions of the PG binder specifications prepared and modified during the research phase. Eventually, the framework and guiding concepts were set, and they are still in use today, for the most part, though there have been refinements in some of the testing procedures, application of the specifications, proposed new test methods, etc.
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From page 151... ...
149 FHWA has continued working with a Multi-Stress Creep and Recovery (MSCR) test to better account for the effects of modified binders.
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150 are – issues with excess fine aggregates being generated, so industry and agencies are working on identifying beneficial uses for these materials. Finer mixes and small nominal maximum aggregate sized mixes (4.75 mm)
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From page 153... ...
151 these tests was then input into software that would predict the rutting and cracking likely to develop. While the low-temperature prediction models were generally acknowledged to correlate fairly well to thermal cracking, the rutting models in particular appeared to have problems.
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From page 154... ...
152 There were many reports from the field of increased mix tenderness. This tenderness interfered with compaction of the mixes.
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From page 155... ...
153 conventional wisdom would say fatigue and rutting typically do not happen in the same mixtures because of their conflicting mechanisms. The mix design procedure favored coarse mixes, but WesTrack suggested that these mixes, in particular, would be prone to performance problems.
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From page 156... ...
154 in the curves and the mixes in the curves did not rut as much as in the tangents. Their theory was that coarse-graded mixes experience more strain in the mastic than fine-graded mixes because there are fewer points of contact between the aggregates.
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From page 157... ...
155 lift thicknesses to allow for better compaction, changing the design gradation or increasing the crushed content to increase VMA, changing release agents and more. The real significance of this document (36)
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From page 158... ...
156 As use of Superpave has become routine in individual states, the use by local agencies and in private work has also increased. In some cases, owners may not realize that they are getting Superpave mixes, but that is what contractors provide.
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