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High Performance Concrete Pavements
Project Summary

CHAPTER 38. WISCONSIN 4 (I-90, Tomah)

Introduction

In September 2002, the Wisconsin Department of Transportation (WisDOT), constructed a high performance concrete pavement section with a design life of 50 years, with no maintenance anticipated over that period. The project is located on I-90 in Monroe County, immediately west of the intersection with STH 16 and approximately 12.9 km (8 mi) west of the split in Tomah, of I-90 and I-94. The test sections are located in the eastbound lanes with the termination of the test sections at structure B-41-111. The general project location is illustrated in Figure 107.

Figure 107. Location of WI 4 project.

Location of WI 4 project. An outline map of Wisconsin shows the WI 4 project in Tomah on I-90 near its intersection with I-94, close to the State’s western border.

Study Objectives

The objective of this study was to construct a pavement that would last for 50 years. Specific design factors considered were:

  • The use of deicing agents, especially salts, may cause premature pavement failure due to determination of the load transfer devices made of plain and epoxy-coated steel.
  • Slab curling is also a cause of premature pavement failure. One key to a long-life pavement is that the pavement is built upon a firm foundation and remains in contact with such. Concrete pavements respond to the environment by changing in three ways: built-in curvature, temperature curling, and moisture warping. When the slab is curled away from the foundation premature cracking may result from stresses incurred.

Some of the benefits of providing this type of technology to Wisconsin are the anticipated lower long-term pavement maintenance costs and reduced rehabilitation and replacement costs due to a longer initial service life. Wisconsin is also beginning to focus on user cost delays. If a longer lasting pavement is developed and placed, user cost delays will decrease as well as increasing safety by reducing the exposure of construction and maintenance crews to traffic.

Project Design and Layout

The test sections are located in the two eastbound lanes of I-90. The project was split into two test sections and one control section as follows (Kemp 2004):

  • Test section 1 is 227 m (745 ft) long, with two 3.6-m (12-ft) lanes and tied concrete shoulders (inside shoulder 1.2 m (4 ft) wide and outside shoulder 3 m (10 ft) wide).
  • Test section 2 is 242.3 m (795 ft) long, with two 3.6-m (12-ft) lanes and tied concrete shoulders (inside shoulder 1.2 m [4 ft] wide and outside shoulder 3 m [10 ft] wide). Stainless steel dowels were used for the load transfer devices utilizing a non-corrodible basket system for the test sections. Shoulders were tied to the pavement using stainless steel tie bars.
  • The control section is 242.3 m (795 ft) long, with two 3.6-m (12-ft) lanes and asphaltic shoulders (inside shoulder 1.2 m [4 ft] wide and outside shoulder 3 m [10 ft] wide). Epoxy-coated dowels placed in standard steel baskets were used for load transfer at the joints.

The current WisDOT pavement design guidelines specify a structure with the following characteristics will be suitable for pavements with a 20-year pavement life:

  • 304.8-mm (12-in.) thick doweled JPCP.
  • 101.6-mm (4-in.) open-graded base course.
  • 152.4-mm (6-in.) dense-graded base course.

The 50-year design had the following characteristics:

  • 342.9-mm (13.5-in.) doweled JPCP.
  • 101.6-mm (4-in.) open-graded base course (No.2).
  • 152.4-mm (6-in.) dense-graded base course.

In addition to the standard design, an increased base section was engineered to carry the improved pavement section. This is to provide a more static base than the standard base and original subgrade. The section has the following properties:

  • 342.9-mm (13.5-in.) doweled JPCP.
  • 101.6-mm (4-in.) open-graded base course (No. 20).
  • 254-mm (10-in.) dense-graded base course (a two-layer system with the first 152.4 mm [6 in.] being a 76.2-mm [3-in.] maximum size and the remaining 101.6-mm [4-in.] being a 38.1-mm [1.5-in.] maximum size, well graded base course).
  • 406.4-mm (16-in.) of breaker run.

State Monitoring Activities

The test section is monitored using Wisconsin's Pavement Monitoring Van. This van is equipped with laser sensors to measure the profile. The laser measurements are used to calculate an International Roughness Index (IRI). The van is also equipped with video cameras that are able to log the section of the highway of interest, and later analyzed for pavement distress. The results of the analysis are used to calculate a Pavement Distress Index (PDI)

A fatigue life will be calculated based upon a backcalculated elastic module. This is calculated from a FWD testing results performed on the various sections.

Rapid chloride permeability tests will be performed at 28, 90, and 365 days to indicate the concrete's resistance to infiltration of salts. In addition, the standard tests of air content, slump, and compressive strength will be monitored at 3, 7, 28, 90, and 365 days. Thermocouples were installed to monitor the temperature of the slab during the curing period along with documentation of the temperature of the base course.

The FHWA Office of Pavement Technology will evaluate the slab in relationship to warpage and curl during the initial curing period. In addition to these tests, regular visual inspections will be conducted and traffic and weather data will be recorded from an automated site located near the project.

Preliminary Results/Findings

The pavement sections were constructed on September 24, 2002. The concrete was a standard mix design utilizing local materials. Type I cement was used in conjunction with a Class C fly ash at a substitution rate of 25 percent. Dowel bars were 38.1-mm (1.5-in.) diameter Type 316 solid stainless steel, 457.2 mm (18 in.) long, and spaced across the joints at 304.8-mm (12-in.) spacings. The transverse joints are perpendicular and spaced at fixed 4.6-m (15-ft) intervals.

The dowels were placed in baskets on the grade. The baskets were constructed from stainless steel wire. The wire had a diameter of 3.2 mm (0.125 in.), which made the baskets flexible. To compensate for this flexibility, the baskets were cut in half on the jobsite. Epoxy-coated steel tie bars were then driven in the ground in front of the baskets to keep the frame from moving forward when the paver passed over them (see Figure 108). Additionally, a concrete spreader deposited 1.5 to 2.3 m3 (2 to 3 yd3) of wet concrete on top of the basket assemblies prior to the slip-form paver moving over the dowel baskets. Visual inspection during the paving along with verification from a dowel bar locater confirmed that the dowels had stayed in place. Dowel baskets, for future projects, should be constructed with a 4.8-mm (0.1875-in.) minimum diameter wire to avoid these issues.

Figure 108. Stainless steel dowels and basket on WI 4 (Kemp 2004).

Stainless steel dowels and basket on WI 4 (Kemp 2004). A photograph shows four stainless steel dowels within a placement basket. The basket is set on a portion of the road's foundation.

Test section 1 was paved shorter than originally planned, and totaled 227 m (745 ft). A construction joint extended into the test section by 15.2 m (50 ft). This joint is to allow the doweled JPCP to abut to the existing CRCP. Stainless steel tie bars for adjoining the shoulder were used in the test sections. The spacing was unintentionally altered from 30 in center-to-center spacing to 24 in center-to-center spacing. This caused the addition used of epoxy-coated tie bar in the last 21.3 m (70 ft) of test section 2.

Points of Contact

Peter Kemp
New Products/New Methods Engineer
(608) 246-7953
peter.kemp@dot.state.wi.us

Steven Krebs
Chief Pavements Engineer
(608) 246-5399

David Leo Larson
(608) 246-7950

Wisconsin Department of Transportation
3502 Kinsman Boulevard
Madison, WI 53704

Reference

Kemp, P. 2004. High Performance Concrete Pavement: Construction Report. Draft Report WI-04-03. Wisconsin Department of Transportation, Madison.

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Updated: 04/07/2011
 

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