South Dakota Department of Transportation
Project Synopsis
SD1996-13

Title: Construction & Evaluation of NMFRC PCC Pavement
Project Researcher: V Ramakrishnan, SDSM&T
Project Manager:
Research Period: 1/1/1900 - 1/1/1900
Status: Completed
Cost: $0.00

Problem Statement:The Technical Panel reviewed the final report "Evaluation of Non-Metallic Fiber Reinforced Concrete (NMFRC) Whitetopping" submitted by Dr. V. Ramakrishnan, SDSM&T. The report accurately discusses all aspects of the research project. The findings from this study have answered many questions about the use of whitetopping and Ultra-Thin Whitetopping (UTW) as a form of pavement rehabilitation of deteriorated or distressed asphalt pavement.

Based on the thickness definitions of whitetopping (4 inches and greater) and UTW (less than 4 inches), the projects constructed as part of this research are considered to be UTWs. These projects were constructed on US14 near MRM 222 west of Ft. Pierre and at the St. Joseph/St. Patrick intersection in Rapid City. Both projects used 3Ms Polyolefin Fiber System, which greatly enhanced many of the hardened concrete properties beyond that of plain concrete. The US14 UTW had four 500 foot test sections. The test sections included two jointed 152 m (500 ft) sections each with a different thickness and two unjointed 152 m (500 ft) sections each with a different thickness. The jointed test sections used a joint spacing of 15.2 m (50 ft). The section design thicknesses were 6.4 cm (2.5 in) and 8.9 cm (3.5 in). The St. Joseph/St. Patrick intersection had a design thickness of 7.6 cm (3 in) and a transverse joint spacing of 6.1 m (20 ft).

Dr. Ramakrishnan worked well with designers, inspectors, and contractors. Dr. Ramakrishnan collected and evaluated a significant amount of data during the construction of these projects and conducted several visual performance inspections through the evaluation period.

The panel believes that the use of NMFRC whitetoppings and UTWs are an alternative that should be considered as a form of rehabilitation for deteriorated or heavily distressed asphalt pavements. However, based on the costs observed on these projects, whitetoppings and UTWs should only be used in locations where an asphalt pavement frequently receives maintenance due to severe rutting or other forms of distress (in locations such as intersections where high volumes of traffic exist). By constructing whitetoppings and UTWs over severely damaged asphalt pavements which require frequent maintenance and rehablilitation, then the adverse affects to businesses as well as time delays and detours for the traveling public should be minimized.

Findings:

Research Objectives:
1  To recommend designs for NMFRC overlays of asphalt concrete pavement.
2  To evaluate constructability and performance of NMFRC white-topping.
3  To evaluate the economic impacts of using NMFRC in white-topping 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 overlays of asphalt concrete pavement.
3  Propose the testing program, including lab and field tests and field evaluations that will be performed. In addition to the same lab and field tests that were performed in SD94-04, testing and evaluation should identify the behavior of the white-topping at joints and uncontrolled cracks. This may include measuring crack widths, curling measurements, and visual surveys.
4  Evaluate white-topping test sections from design through construction and subsequent service performance with special attention to the effects of joint spacing and thickness. White-topping test sections will be constructed on SD44 near the Fish Hatchery in Rapid City and on US14 near MRM 222 west of Pierre. The Panel envisions the following test and control sections at each site: two jointed 152m (500 ft) test sections each with a different thickness; two unjointed 152m (500 ft) test sections each with a different thickness; and one 305m (1000 ft) asphalt overlay control section. (a) In conjunction with SDDOT design personnel, review on the design and plans developed for the white-topping construction. (b) In conjunction with SDDOT design personnel, design the concrete mix. (c) Conduct hardened concrete tests on the mix design(s) to ensure desired properties are obtained. (d) Attend preconstruction meeting(s) and recommend NMFRC construction methods. (e) Perform quality control testing, record weather conditions, and observe and record construction activities. (f) Conduct performance tests of hardened concrete on the collected field samples. (g) Periodically conduct condition surveys to evaluate the field performance of the constructed white-toppings.
5  Recommend design, testing, and construction guidelines for using NMFRC in white-topping applications based on results from the test sections.
6  Using cost data available from SDDOT and others, compare the performance and life-cycle costs of NMFRC white-topping and asphalt overlays. NMFRC cost estimates should assume that its use becomes common construction practice and is no longer experimental.
7  Provide an interim report 90 days after each section is constructed. The interim report should document the construction evaluation, material properties, early performance of the test and control sections, and should include sketches showing relative locations of each test section along with descriptive text. Therefore, two interim reports should be submitted, each being 90 days after the completion of its respective construction completion date. Careful planning of each interim report will allow incorporation of each into the final report.
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: