Validation of the New Mix Design Process for Cold In-Place Rehabilitation Using Foamed Asphalt, 2007

Asphalt pavement recycling has grown dramatically over the last few years as a viable technology to rehabilitate existing asphalt pavements. Iowa's current Cold In-place Recycling (CIR) practice utilizes a generic recipe specification to define the characteristics of the CIR mixture. As CIR continues to evolve, the desire to place CIR mixture with specific engineering properties requires the use of a mix design process. A new mix design procedure was developed for Cold In-place Recycling using foamed asphalt (CIR-foam) in consideration of its predicted field performance. The new laboratory mix design process was validated against various Reclaimed Asphalt Pavement (RAP) materials to determine its consistency over a wide range of RAP materials available throughout Iowa. The performance tests, which include dynamic modulus test, dynamic creep test and raveling test, were conducted to evaluate the consistency of a new CIR-foam mix design process to ensure reliable mixture performance over a wide range of traffic and climatic conditions. The “lab designed” CIR will allow the pavement designer to take the properties of the CIR into account when determining the overlay thickness.

Effective Shoulder Design and Maintenance, 2007

Granular shoulders are an important element of the transportation system and are constantly subjected to performance problems due to wind- and water-induced erosion, rutting, edge drop-off, and slope irregularities. Such problems can directly affect drivers’ safety and often require regular maintenance. The present research study was undertaken to investigate the factors contributing to these performance problems and to propose new ideas to design and maintain granular shoulders while keeping ownership costs low. This report includes observations made during a field reconnaissance study, findings from an effort to stabilize the granular and subgrade layer at six shoulder test sections, and the results of a laboratory box study where a shoulder section overlying a soft foundation layer was simulated. Based on the research described in this report, the following changes are proposed to the construction and maintenance methods for granular shoulders: • A minimum CBR value for the granular and subgrade layer should be selected to alleviate edge drop-off and rutting formation. • For those constructing new shoulder sections, the design charts provided in this report can be used as a rapid guide based on an allowable rut depth. The charts can also be used to predict the behavior of existing shoulders. • In the case of existing shoulder sections overlying soft foundations, the use of geogrid or fly ash stabilization proved to be an effective technique for mitigating shoulder rutting.

Consumer Advisory Bulletin, Caution: Watch What You Sign, October 2003

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Caution: Watch What You Sign

Sign of the Times, January 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, February 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, March 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, April 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, May 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, June 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, July 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, August 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, September 2008

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, May 2009

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, June 2009

Newsletter produced by Deaf Services Commission of Iowa

Sign of the Times, January 2009

Newsletter produced by Deaf Services Commission of Iowa