|FHWA > Engineering > Pavements > Concrete > High Performance Concrete Pavements: Project Summary > Chapter 7|
High Performance Concrete Pavements
|250-MM (10-IN.) JPCP|
4.6-M (15-FT) JOINT SPACING
|38-mm (1.5-in.) diameter polyester and type E fiberglass dowel bars (RJD Industries)||Section 1 (150 ft long, 10 joints)|
|38-mm (1.5-in.) diameter vinyl ester and type E fiberglass dowel bars (Morrison Molded Fiber Glass Company)||Section 2 (150 ft long, 10 joints)|
|38-mm (1.5-in.) diameter vinyl ester and type E fiberglass dowel bars (Creative Pultrusions, Inc.)||Section 3 (150 ft long, 11 joints)|
|Fiber-ConT dowel bar, consisting of a fibrillated type E fiberglass and polyester resin tube filled with hydraulic cement (Concrete Systems, Inc.)||Section 4 (150 ft long, 10 joints)|
|38-mm (1.5-in.) diameter carbon steel rods clad with grade 316 stainless steel (Stelax Industries Inc.)||Section 5 (150 ft long, 10 joints)|
|38-mm (1.5-in.) diameter epoxy-coated steel dowel bars||Section 7 (150 ft long, 10 joints)||Section 6 (150 ft long, 10 joints)|
IDOT installed an automatic traffic recording station at the project site in February 2000. Traffic data are recorded using a Peek series 3000 ADR traffic classifier (Gawedzinski 2000). No traffic data are currently available. Before the pavement was opened to traffic, IDOT conducted FWD testing on the experimental sections in June 1999. Results from the FWD testing program are plotted in Figures 22 and 23 (Gawedzinski 2000). Figure 22 shows the average load transfer for the seven experimental sections in both the driving and passing lanes, whereas Figure 23 shows the average maximum joint deflection measured for each of the seven experimental sections in both the driving and passing lanes. Although the joint deflections are low, the load transfer efficiencies (typically between 80 and 90 percent) are not as high as might be expected for a new concrete pavement. These initial FWD results will serve as a baseline for comparison with future testing values.
Figure 22. Load transfer efficiency on IL 3 (Gawedzinski 2000).
Figure 23. Maximum joint deflections on IL 3 (Gawedzinski 2000).
This pavement is performing well after 1 year of service. None of the joints are exhibiting any signs of distress. IDOT will continue monitoring the project to assess the relative performance of the different dowel bar types and of the sealed/unsealed joints.
FWD tests are conducted semi-annually along with periodic visual observations of joint performance. Traffic data are collected using an ADR 3000, manufactured by Peek Traffic. The data are periodically polled and converted to ESALs using standard IDOT conversion factors. A summary of the cumulative ESALs is provided in Table 11.
Joints are also periodically observed, to look for signs of joint deterioration or distress. Joints were formed using a thin saw cut and sealed with an ASTM D 6690 (formerly ASTM D 3405) hot-pour joint seal material. Problems affecting ride quality became apparent, due to several of the joints being overfilled with the 3405 joint seal material. Subsequent evaluations noted failure of the 3405 joint seal material to maintain a bond with either side of the pavement at the joint.
Several joints were observed where the joint seal material was either missing from the wheelpaths or had been pushed deeper in the joint and was debonded from both sides of the pavement joint. Small rocks were also compressed into the joint seal material at the joint surface. As with the other Illinois sites, no obvious signs of joint distress were apparent during the visual observations.
Similar behavior as observed at the older two sites (IL 1 and IL 2) is shown in the following figures. The control set (38.1-mm [1.5-in.] diameter epoxy-coated steel), unsealed epoxy-coated steel bars, stainless steel clad carbon steel bars, and fibrillated wound fiber composite bars exhibit better LTE and lower joint deflections than the pultruded fiber composite bars, but do not show excessive joint deflection indicating failure of the joints. The pavement at Jacksonville (IL 3) was constructed on a cement aggregate mixture subbase (CAM 2 with a minimum of 200 lbs of cement per cubic yard) rather than a granular subbase as in Naperville (IL 2) or a bituminous aggregate mixture subbase (BAM) at Williamsville (IL 1).
An additional FWD test was performed on the driving lane of US 67 in November of 2003 to evaluate the joint deflections that had occurred earlier that year. Testing was not conducted in the passing lanes due to traffic control problems at the time of the November tests. The large shift in average joint deflection vales between the April and October tests necessitated the November retest. More frequent testing is scheduled for 2004.
Deflection data are presented in Figures 24 through 26. It is observed that the FRP bars are approaching (or exceeding) the critical LTE value of 70 percent, calling into question the capability of these load transfer mechanisms to provide long-term performance.
Figure 24. Driving lane load transfer efficiency vs. ESALs (Gawedzinski 2004).
Figure 25. Passing lane load transfer efficiency vs. ESALs (Gawedzinski 2004).
Figure 26. Average load transfer efficiency vs. average pavement temperature (Gawedzinski 2004).
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.
---. 2004. TE-30 High Performance Concrete Pavements: An Update of Illinois Projects. Illinois Department of Transportation, Springfield.
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