In this issue ... Concrete Pavement Reconstruction, Subbases/Subgrades

Concrete Pavement Reconstruction "Plays in Peoria"
Transportation Industry Unites to Oppose Fuel Tax Suspension
In Memoriam

"Will it play in Peoria?" The question is commonly asked to determine if a product or event will appeal to mainstream America.

In the case of the I-74 reconstruction project, concrete pavement is well-suited for residents and travelers in Peoria, Ill.

The project spanned 11 miles along Interstate 74 in downtown Peoria and used more than a half million cubic yards of concrete, 69,789 tons of which were recycled.

Of the 11 miles, eight involved complete removal and replacement with new concrete pavement. The remaining three miles were upgraded and patched with bituminous pavement.

Incorporating a public outreach program in the planning process became critical to the success of the project. I-74 is used by more than 60,000 cars daily, and the project route included two main hospitals that had to remain in operation.

Illinois DOT hired public relations firm Hill & Knowlton to develop a program that would keep commuters updated on progress and ensure that the needs of motorists and businesses along the way were taken into consideration.

A website, "Upgrade 74," received thousands of hits per day. Radio and television ads featuring the project's official mascot "Jack Hammer" provided safety tips. And the establishment of a speakers' bureau made over 200 presentations to various local organizations on the project's implications.

"This project highlights the success of the Interstate Highway system," said Norman Stoner, Illinois Division, Federal Highway Administration. "Illinois DOT and the industry have created a prospective showcase for the future. This project contains new, solid, smooth, and durable products that improve the geometrics of ramps, while respecting community aesthetics."

From the compliments from various I-DOT personnel, the attention to detail in presentations given on the project throughout the open house, and comments relayed from the public, I-74's concrete pavement reconstruction is recognized as a safer, stronger surface for Illinois commuters and as an example of the Interstate's potential.

"The I-74 project marks a marquee achievement for I-DOT," said Milton R. Sees, P.E., I-DOT, Director of Highways/Chief Engineer. "It represents the holistic project approach we strive for."

"As time has moved on, I-DOT has had to pay more attention to both environmental concerns and the needs of the traveling public. This project represents that state-of-the-art approach to construction, in an urban area with traffic management in mind."

An open house for the project attracted over 150 people. Attendees included representatives from the Federal Highway Administration, Illinois DOT (I-DOT), contractor firms, and other sectors of the industry. The event was co-sponsored by the Illinois Chapter—ACPA, Illinois Ready Mixed Concrete Association, Illinois DOT, ACPA national, and Concrete Reinforcing Steel Institute.

For more information, please contact Randy Riley, Illinois Chapter—ACPA, at 217-793-4933.

The American Concrete Pavement Association (ACPA) recently joined other transportation partners to oppose initiatives in the U.S. Senate to suspend the federal fuel tax.

ACPA's chief executive sent out a letter stating the concrete pavement industry's specific concerns regarding this issue.

"We are strongly opposed to efforts to suspend the gas tax because of the potential to limit the nation's road construction program," said Gerald F. Voigt, P.E., ACPA President & CEO.

"By limiting construction, you limit the potential to reduce the billions of gallons of fuel that Americans waste sitting in congested traffic."

Also, in a letter to U.S. Senate Majority leader Bill Frist (R-TN) and Minority leader Harry Reid (D-NV), ACPA and nine other organizations addressed the negative consequences such measures would impose to urge them to oppose the suspension.

Subgrades

The subgrade is the natural ground, graded and compacted, on which the pavement is built. Preparation of the subgrade should include:

1. Compacting soils at moisture contents and densities that will ensure uniform and stable pavement support.

2. Whenever possible, setting gradelines high enough and making side ditches deep enough to increase the distance between water table and pavement.

3. Crosshauling and mixing soils to achieve uniform conditions in areas where there are abrupt horizontal changes in soil type.

4. Using selective grading in cut and fill areas to place the better soils nearer to the top of the final subgrade elevation.

5. Improving extremely poor soils by treatment with cement or lime, or importing better soils, whichever is more economical.

Subbases

Constructing an effective subbase includes several factors, including subgrade soil type, environmental conditions, and amount of heavy truck traffic.

Here are six tips for achieving that objective and constructing the right subbase:

1. Select subbase materials that meet minimum requirements for preventing mudpumping of subgrade soils.

2. Specify gradation controls that will ensure a reasonably constant subbase gradation for individual projects.

3. Specify a minimum subbase depth of 4 in.

4. Specify a minimum density for untreated subbases of 95 percent of AASHTO T99 (standard proctor) for most projects.

5. Specify a cement-treated or lean concrete subbase that provides a strong and uniform support for the pavement and joints; provides an all-weather working platform; and contributes to smoother pavements by giving firm support to the forms or paver during construction

6. Specify a permeable subbase for pavements carrying high volumes of heavy trucks for which past experience indicates the potential for pavement faulting and pumping.

For additional information, see ACPA publication, "Subgrades and Subbases for Concrete Pavements" (TB011P). To order ACPA publications, log-in to the ACPA members only section (to receive the member discount) at www.pavement.com; or call toll-free 1-800-868-6733.

The new V2 hydraulically adjustable paving mold accomodates fast and simple width changes with virtually any paver operating in the field today.

The V2 comes standard with front and rear molds for width variation. The paving mold also features a spreader plow for hydraulic vertical movement, including telescopes that also accomodate quick and easy width changes.

ACPA Concrete Pavement Progress is published 12 times per year and covers current practices and case histories in the concrete pavement industry. ACPA Concrete Pavement Progress is distributed free of charge to public officials, ACPA members, executive committee, board of directors, and affiliated chapter/state paving associations.

All rights reserved. Copyright 2006 by the American Concrete Pavement Association. No portion of this publication may be reproduced mechanically or electronically without the expressed written permission of the American Concrete Pavement Association.