High Performance Concrete Pavements
CHAPTER 8. ILLINOIS 4 (Route 2, Dixon)
A fourth project evaluating alternative dowel bars was constructed by the Illinois Department of Transportation (IDOT) in April 2000. The experimental project is located in the driving lane of the northbound direction of Illinois Route 2 in Dixon (see Figure 27) where it replaced an existing concrete pavement (Gawedzinski 2000).
Figure 27. Location of IL 4 project.
Although not an official TE-30 project, this project carries on IDOT's investigation of alternative dowel bar materials. The alternative dowel bar materials used in the project included stainless steel tubes filled with cement grout, stainless steel clad carbon steel tubes, and fiber composite tubes filled with cement grout. Two different diameters, 38 mm (1.5 in.) and 44.5 mm (1.75 in.), were used for the stainless steel tubes and for the stainless steel clad dowels. The fiber composite tubes were formed using a pultrusion process and were approximately 50 mm (2 in.) in diameter. The pultrusion process produced a much smoother bar, compared to the first generation, fibrillated bars. Additionally, two different methods of securing the bars to the baskets, welding and using cable ties, were used in the four sections. More detailed construction information is provided by Gawedzinski (2004).
Project Design and Layout
The pavement design for each section is a 240-mm (9.5-in.) doweled JPCP placed over a 300-mm (12-in.) granular base course (Gawedzinski 2000). Transverse joints are spaced at 4.6-m (15-ft) intervals and are sealed with a hot-poured sealant. A tied curb and gutter is placed adjacent to the outer driving lane of the project.
The experimental project consists of five test sections evaluating the following alternative dowel bar materials (Gawedzinski 2000):
- Fiber-Con™ dowel bar, manufactured by Concrete Systems, Inc. and consisting of a pultruded fiber composite tube composed of type 'E' fiberglass and polyester resin and filled with hydraulic cement.
- 38-mm (1.5-in.) diameter, 2.76 mm (0.109 in.) thick grade 316 stainless steel tube filled with cement grout.
- 44.5-mm (1.75-in.) diameter, 2.76 mm (0.109 in.) thick grade 316 stainless steel tube filled with cement grout.
- 38-mm (1.5-in.) diameter carbon steel rods clad with grade 316 stainless steel, manufactured by Stelax Industries Inc.
- 44.5-mm (1.75-in.) diameter carbon steel rods clad with grade 316 stainless steel, manufactured by Stelax Industries Inc.
Conventional load transfer devices are installed in JPCP sections adjacent to the experimental pavement sections.
State Monitoring Activities
Traffic data are recorded using a Peek series 3000 ADR traffic classifier. IDOT obtained baseline FWD deflection data after the pavement was constructed and will monitor its performance on at least a semi-annual basis.
Interim Project Status, Results, and Findings
Data has been collected on a semi-annual basis for the past 3 years. The cumulative ESALs are provided in Table 12. Results of deflection testing are illustrated in Figures 28 and 29.
Table 12. Data Collection Date and Cumulative ESALs (Gawedzinski 2004)
Figure 28. Driving lane load transfer efficiency vs. ESALs (Gawedzinski 2004).
Figure 29. Average load transfer efficiency vs. average pavement temperature (Gawedzinski 2004).
Current Observations (Gawedzinski 2004)
At the time of construction, all of the test joints were unsealed. Visual observations of the joints show all of the joints performing well with slight spalling possibly due to the pavement being cut too early. None of the joints show accumulation of incompressible materials in the joint or any significant spalling due to the joints "locking up." Additional monitoring will continue. The LTE and joint deflection graphs show behavior expected for relatively new pavements.
Points of Contact
Illinois Department of Transportation
Bureau of Materials and Physical Research
126 E Ash Street
Springfield, IL 62704
Gawedzinski, M. 2000. TE-30 High Performance Rigid Pavements Illinois Project Review. Illinois Department of Transportation, Springfield.
---. TE-30 High Performance Concrete Pavements: An Update of Illinois Projects. Illinois Department of Transportation, Springfield.