Transition Plan-Executive Summary

BACKGROUND

At the beginning of the Lead States Program, alkali-silica reactivity (ASR) was not considered one of the more dynamic outputs from the SHRP suite of research products. ASR, although a noted problem since the 1930s in major dam construction, was not an "accepted" problem of the current highway industry. It soon became obvious that there was a bigger problem with ASR than first recognized. The Team tackled the implementation in four steps:

1. Convince the States and industry that a problem existed;
2. Identify the presence, characteristics, and extent of the problem;
3. Define the deterioration mechanism; and
4. Work toward cost effective mitigation measures and guidelines.

The Team membership included representation from industry, academia, and FHWA. The response capabilities of the membership were considerably varied, due to the differing operational and business practices of the member organizations.

The core of the Lead State Team for ASR included the professional staff of states, agencies, and private industry involved in the early implementation efforts. This team included:

• DOT - Pennsylvania, Virginia, North Carolina, South Dakota, and New Mexico
• Federal - FHWA and the Department of Energy
• Private Industry - FMC
• Academia - University of New Hampshire

ACCOMPLISHMENTS

The Lead States Team has many significant accomplishments, including:

• A survey of State Highway Agencies to assess the extent of ASR.
• An updated SHRP "Handbook for the Identification of ASR in Highway Structures."
• The development of an AASHTO Guide Specification on ASR-Resistant Concrete.
• An updated SHRP ASR bibliography, adding an electronic format.
• A Q&A web forum with on-line training materials.
• An ASR glossary of terms.
• An aggregates databases and a list of resources.
• A list of ASR Lead State contacts, along with a bulletin board for technical assistance.
• Providing technical assistance to other State highway agencies and electric companies.

Lead State Team Members participated in ASR-related research that included:

• Testing existing pavement.
• Developing ASR mitigation processes.
• Developing a new environmentally safe ASR field test.
• Preventing ASR reoccurrence when using recycled aggregate from ASR affected concrete, and
• Improving laboratory test methods for determining the effectiveness of ASR mitigation techniques.

Overall, the ASR Lead State Program fostered an expanded knowledge of mitigation technologies with a better understanding of materials, including lithium, glass, and fly ash. The Program also led to the development and fostering of a FHWA/ACI durability workshop that is now available as a training course, an expanded focus on international coordination.

TRANSITION ISSUES

While much was accomplished, the effort did more to point out how much still remains to be done. The following issues are offered to AASHTO for future consideration:

Test Methods - Champion the need for test methods to rapidly and reliably evaluate performance of concrete mixes for ASR susceptibility and contribute resources toward the answering of this need. Decisions based on the use of data from tests currently in use, carry an unacceptable risk or conservative cost with regard to high performance concrete and extended service life parameters.

Mitigation of ASR in Existing Concrete - Provide continued guidance for managing or providing ASR mitigation in existing concrete. Provide a Program Guide for Existing Facility ASR Mitigation for use by State agencies. The guide should include decision trees, recommended mitigation practices, and program application guidance; to include 1) use of available lithium technology and other strategies, 2) use of available technology combinations, and 3) mitigation time lines based on aggregate reactivity for cost-effective control of ASR.

Managing ASR in New Construction - Provide continued guidance for managing ASR in new construction through state of the practice evaluation. Continue to monitor and evaluate work being done to improve aggregate evaluation for ASR and test methods, use of pozzolanic mitigation materials, and advances or improvements in forestalling or mitigating ASR degradation of Portland cement concrete. Knowledge of impacts on mitigation, such as fly ash composition, fly ash addition rate and aggregate lithology/reactivity is essential for the development of effective mitigation actions, compared to current one-size-fits-all procedures for designing ASR-proof concrete.

Monitoring Existing ASR Test Sites - Champion the continued monitoring of existing ASR test sites along with timely reporting. Verification of the ASR remediation trials and effective treatments is needed and should include cost/benefit ratios of each recommended remediation or treatment. Such work needs to factor in the effect of traffic, climate, aggregate reactivity, original and available cement alkali, deicing and freeze-thaw potential. As field-test site performance data becomes available, there will be a need for data interpretation and evaluation, recommendations for new research, and technology transfer and implementation efforts. Provide a single dedicated collection and archive location for oversight information and data collected from existing and future ASR test sites.

Technology Transfer and Information Management

Develop and continue support of the ASR Web Site after September 30, 2001 when the current contract expires.

Continue collecting and distributing ASR information under one uniform umbrella, including the publication of an ASR-related newsletter.

Continued technology transfer activities, outreach and other communication efforts as a greater depth of ASR knowledge is reached

Ad Hoc Group

Identify and commit personnel to the ASR effort through an Ad Hoc Group to work with AASHTO Subcommittee(s). The Subcommittee(s) sponsoring the formation of the ASR Ad Hoc Group should seek experts from the individual AASHTO member states to participate. The Ad Hoc Group should participate in ASR-related activities sponsored by ACI, ASTM, ICAR, CANMET, and PCA. Within the Ad Hoc Group, the ASR Lead State Team should be continued. The Group should commit to assisting these experts to be given the time and funding to participate in the effort.

Future Funding

To effectively promote ASR technology, consideration should be given to establishing a source of dedicated funding. This could be through a pool fund. Creative ways should also be developed that would better be able to combine private and public funding to raise support, and other cooperative agreements with the private sector.

CONCLUSION

In conclusion, the ASR Lead State Team has championed the further awareness of ASR, and the continued development and promotion of ASR avoidance and mitigation. In transitioning the program to AASHTO, the ASR Lead State Team looks forward to a strong cooperative effort with the AASHTO Subcommittees in carrying on the program.

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