Ultra-thin Portland Cement Concrete Overlay Extended Evaluation

Ultra-thin Portland Cement Concrete Overlay Extended Evaluation

Author: James K. Cable

Publisher:

Published: 2005

Total Pages: 114

ISBN-13:

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The Iowa ultra-thin project demonstrated the application of thin portland cement concrete overlays as a rehabilitation technique. It combined the variables of base preparation, overlay thickness, slab size, and fiber enhancement into a series of test sections over a 7.2-mile length. This report identifies the performance of the overlays in terms of deflection reduction, reduced cracking, and improved bonding between the portland cement concrete (PCC) and asphalt cement concrete (ACC) base layers. The original research project was designed to evaluate the variables over a 5-year period of time. A second project provided the opportunity to test overlay rehabilitation techniques and continue measurement of the original overlay performance for 5 additional years.


Field Evaluation of Bonded Concrete Overlays

Field Evaluation of Bonded Concrete Overlays

Author: Shiraz D. Tayabji

Publisher:

Published: 1986

Total Pages: 124

ISBN-13:

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Field load testing was conducted by CTL at five sites in Iowa during April 1986. This report presents the results of field testing, analysis of results, and recommendations to incorporate study results in Iowa's design procedure for bonded concrete overlays.


Evaluation of the Construction and Performance of Multiple Layer Polymer Concrete Overlays

Evaluation of the Construction and Performance of Multiple Layer Polymer Concrete Overlays

Author: Michael M. Sprinkel

Publisher:

Published: 1987

Total Pages: 42

ISBN-13:

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This interim report presents the results after 5 years of a study undertaken to evaluate multiple layer polymer concrete overlays over a 10-year period. The report indicates that an overlay of low permeability and high skid resistance can be successfully installed by a contractor or by state or federal labor forces with a minimum of disruption to traffic. With one exception, the initial condition of the I0 overlays that have been evaluated since 1981 was good to excellent from the standpoint of permeability, skid resistance, and bond, although some overlays were better than others. Also, with one exception, the overlays were in good to excellent condition after one year in service, but the permeability had increased and the bond strength and skid resistance had decreased significantly. Although evaluations made at 3 years and 5 years of age showed a continuing decrease in skid number and bond strength and an increase in permeability, three overlays near Williamsburg had an acceptable skid number and permeability at 5 years of age, but these overlays can be expected to delaminate further at an age of 5 to 10 years, because the concrete surface was not properly prepared prior to placing the overlays and because moisture, temperature change, and traffic deteriorate the bond interface. Multiple layer polymer overlays constructed in accordance with the special provision of March 1987, can be assumed to have a useful life of 10 years and to provide an economical alternative for extending the life of decks for which maintenance should be done during off-peak traffic periods.


Polymer Concrete Overlay Evaluation

Polymer Concrete Overlay Evaluation

Author: Justin Dahlberg

Publisher:

Published: 2016

Total Pages: 244

ISBN-13:

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The objectives of this work were to document the state-of-the-practice with respect to polymer concrete overlays, document the placement of two overlays in Iowa, monitor the field performance of the overlays over a two-year period, and relate their performance to material usage and/or workmanship. The two bridges - a Johnson County, Iowa bridge over I-80 on 12th Avenue in Coralville, and the Keg Creek Bridge on Hwy 6 in western Iowa, 10 miles east of Council Bluffs - were overlaid during the summer/fall of 2013. The process by which each bridge was overlaid was similar in many ways, although a few slight differences existed. Over time, each overlay has generally performed quite well with only a few areas of exception. It is believed that these localized areas likely underperformed due to poor deck preparation, improper polymer mixing, snowplow impact, or a combination thereof.