Improving Guidance of AASHTO R 80/ASTM C 1778 for Alkali-Silica Reactivity (ASR) Potential and Mitigation

The objectives of this research are to improve guidance in AASHTO R 80 and ASTM C 1778 through the following: (1) Constructing and evaluating field exposure blocks with varying concrete materials placed in diverse environmental conditions to supplement the existing information. (2) Enabling better benchmarking of current performance and job-mixture tests that have been or are being developed currently. To achieve the objectives of this research study, concrete blocks will be cast and exposed to a range of real highway environmental conditions, alkali loadings, and cement contents to provide the crucial long-term benchmarking for the developments of ASR test methods for job mixtures and to validate and/or calibrate the prescriptive measures in AASHTO R 80 and ASTM C 1778. The results from the exposure blocks cast in this research study are expected to improve current guidelines for assessing ASR in field concrete in real environmental conditions. A sufficient number of concrete mixtures should be considered to include the following variables: (1) A range of fine and coarse aggregates (from non-reactive to very highly reactive) with an emphasis on moderately reactive aggregates; (2) Various alkali loading levels, as achieved through a range of cementitious contents (300-445 kg/m³; 500-750 lbs./yd³) and use of cements of various alkali levels (0.4%-1.0% Na₂O eq.) in the range used in pavements and highway structures with an emphasis on lower alkali loadings; (3) A range of SCM types and contents (0 to 50% SCM); and (4) Variation in environmental exposure; blocks from each mixture will be placed in at least three different climate locations to represent various temperature/humidity ranges across the United States as reflected in AASHTO R 80/ASTM C 1778. In addition to concrete blocks, samples will also be cast from each mixture for laboratory testing using the current and most promising performance tests for assessing aggregate reactivity and mitigation of ASR. The performance of the concrete exposure blocks will need to be monitored indefinitely beyond the proposed study period. This may include further data collection and evaluation and any refinement of AASHTO R 80/ASTM C 1778 in a future project. s.

Language

  • English

Project

  • Status: Active
  • Funding: $650000
  • Contract Numbers:

    Project 10-103

  • Sponsor Organizations:

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Jawed, Inam

  • Performing Organizations:

    University of Texas, Austin

    Center for Transportation Research, 3208 Red River Street
    Austin, TX  United States  78705
  • Principal Investigators:

    Drimalas, Thano

  • Start Date: 20190615
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01672254
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 10-103
  • Files: TRB, RIP
  • Created Date: Jun 18 2018 3:03PM