Development of Mixture Designs for Pumpable Concrete for Extreme Weather

With the recent budget crisis, U.S. Departments of Transportation (US DOTs) are trying to extend their construction funds while still providing long lasting and durable infrastructure. This is especially challenging in locations where there is extreme weather, as infrastructure is often replaced more frequently. In concrete structures, cement is the most expensive ingredient and the largest contributor to the carbon footprint. It can also lead to increased cracking through shrinkage.The initial cost and long term performance of concrete would benefit from the reduction of cement in concrete mixtures. One area where states have begun to economize their construction materials is in the use of "optimized graded concrete". These concrete mixtures are designed to use less cement, and use proportionately more aggregate with a more controlled distribution of aggregate sizes. This aggregate control allows a concrete mixture to have increased workability and strength. However, research has shown that historic design techniques for optimized graded concrete do not work for all aggregate sources and that current DOT specifications are inadequate and do not ensure the benefits of optimized graded concrete. Another study has aimed to improve optimized graded concrete specifications for slip formed paving concrete. This research will extend the study to a larger number of materials and focus on the performance of these materials in extreme environments, specifically freezing environments. To provide freeze thaw durability to concrete, microscopic bubbles are added with specialized admixtures during the mixing process. These bubbles provide places for freezing water to escape once the concrete has hardened. During pumping it has been widely documented that the pressure cycles cause the bubbles to implode and then reform when the pressure is removed. Past research has shown that this process can coarsen the air void system in fresh concrete and ultimately threaten the freeze thaw durability of the concrete. This study will seek to better understand this process and ensure that frost durable concrete can be achieved. Implementation will allow immediate changes to be made to the optimized graded concrete specifications for structural concrete.

    Language

    • English

    Project

    • Status: Active
    • Funding: $369900.00
    • Contract Numbers:

      DTRT13-G-UTC36

      SPTC 14.1-38

    • Sponsor Organizations:

      Oklahoma Department of Transportation

      200 NE 21st Street
      Oklahoma City, OK  United States  73105

      Research and Innovative Technology Administration

      University Transportation Centers Program
      1200 New Jersey Avenue
      Washington, DC  United States  20590
    • Performing Organizations:

      Oklahoma State University, Stillwater

      School of Civil & Environmental Engineering
      207 Engineering South
      Stillwater, OK  United States  74078
    • Principal Investigators:

      Ley, Tyler

    • Start Date: 20141001
    • Expected Completion Date: 0
    • Actual Completion Date: 20160930
    • Source Data: RiP Project 37441

    Subject/Index Terms

    Filing Info

    • Accession Number: 01543051
    • Record Type: Research project
    • Source Agency: Southern Plains Transportation Center
    • Contract Numbers: DTRT13-G-UTC36, SPTC 14.1-38
    • Files: UTC, RiP
    • Created Date: Nov 4 2014 1:00AM