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South Dakota Department of Transportation
Project Synopsis
SD1996-14


Title: Construction & Evaluation of NMFRC Bonded Overlay
Project Researcher: ,
Project Manager:
Research Period: -
Status: New
Cost: $0.00

Problem Statement:Many of SDDOTs Portland cement concrete pavements (PCCP) are nearing or have exceeded their design lives. Therefore, normal rehabilitation techniques (i.e. - patching, joint repairs, mudjacking, grinding, etc.) are not adequate or cost effective. Approximately 10 years ago, SDDOT applied a thin-bonded concrete overlay to a severely distressed plain jointed PCCP. Since construction of the overlay, the pavement has experienced increasing traffic levels and is continuing to perform well. The use of thin-bonded overlays has not progressed because the construction costs were high. The costs were elevated due to the extensive surface preparations and structural repairs of the existing pavement that had to be performed to prevent the reflection of underlying distresses through the thin-bonded overlay.

Recent studies of non-metallic fiber reinforced concrete (NMFRC) indicate that this material has the potential to be used in thin-bonded overlay applications with reduced surface preparations and structural repairs. Although underlying distresses may result in cracks in the NMFRC thin-bonded overlay, the materials ability to maintain its structural integrity after cracking could permit reduced surface preparations and structural repairs. The enhanced NMFRC properties could also allow overlays that are thinner than conventional bonded overlays with equal or longer service lives. FRC may also reduce spalling even in concrete with quartzite aggregate that has a higher thermal coefficient than other aggregate types. Furthermore, 3Ms polyolefin fibers have advantages over steel fibers in that they are chemically resistant and have a lower corrosive potential.

Several problems must be addressed before this materials use is accepted. The constructability and economic impacts of using these fibers must be determined in order to support its continued use. Design criteria must be established. Methods for determining thin-bonded overlay thickness and joint spacing must be developed. The effectiveness of bond, load transfer, and the behavior of jointed and unjointed slabs should be evaluated.

Favorable performance of the relatively small NMFRC test sections and the approved recommendations of SD94-04, suggest that SDDOT should pursue construction of a thin-bonded overlay test section which will exhibit full-scale behavior using a fiber addition rate of 15 kg/m3 (25 lbs/yd3).

Findings:

Research Objectives:
1  To recommend NMFRC thin-bonded overlay designs that will enhance PCCP performance.
2  To evaluate constructability and performance of NMFRC thin-bonded overlays.
3  To evaluate the economic impacts of using NMFRC in thin-bonded overlay applications.

Research Tasks:
1  Meet with the Technical Panel to review the research topic and work plan.
2  Review and summarize literature relevant to FRC.
3  Propose the testing program, including lab and field tests and field evaluations that will be performed. Testing and evaluation needs to be performed on the NMFRC thin-bonded overlay that will help identify the behavior of the pavement at joints and
4  Evaluate a thin-bonded overlay pavement from design through construction and subsequent service performance with special attention to the effects of load transfer, joint spacing, thickness, and delamination. At a minimum, the Panel would like the tes
5  Recommend design, testing, and construction guidelines for using NMFRC in thin-bonded overlays based on results from the test sections.
6  With assistance from SDDOT and others, obtain cost data for comparing the performance and life-cycle costs of NMFRC thin-bonded overlays. NMFRC cost estimates should reflect that its use is common construction practice and no longer experimental.
7  Provide an interim report 90 days after the NMFRC thin-bonded overlay is constructed. The interim report should document the construction evaluation, material properties, early performance of the test and control sections, and sketches showing the lo
8  Submit a final report summarizing relevant literature, research methodology, test results, specifications, design standards, conclusions, and recommendations.
9  Make an executive presentation to the SDDOT Research Review Board summarizing the findings and conclusions.

Documents Available:

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