Unbonded Concrete Overlay on Existing Pavement in Washington County

April 2, 2020

A rural roadway in Washington County, Nebraska was suffering from severe alkali-silica reactivity (ASR) caused by swelling and cracking due to the reaction of the highly alkaline cement paste and the non-crystalline silica when exposed to moisture.

A new layer of pavement needed to be placed over the existing road, and the project engineer wanted a long-term and cost effective solution. REFLECTEX® Rapid Install was used as an interlayer for the unbonded concrete overlay. REFLECTEX has the ability to lower surface temperatures during applications which reduces the overall stress on the concrete pavement causing less potential for cracking.

The interlayers solar reflective properties reduce surface temperature by up to 50°F, eliminating the need to cool the surface with water. By replacing the traditional asphalt interlayer, REFLECTEX Rapid Install significantly reduces installation time and cos and allows for fewer construction delays and traffic disruptions.

The geotextile was installed over seven miles of roadway using the ProGrip™, an adhesive that replaces the traditional nail down installation method. Using the adhesive allows for a quicker and more efficient installation, and prevents the fabric from flapping in the wind as it is being installed. It also reduces the cost of labor and materials by up to 30%.

Since there were so many pavement patches in the original road, the traditional method of nailing down the fabric would have been very difficult because different sized nails would have to have been used. The REFLECTEX Rapid Install system was chosen because it’s an innovative solution that’s easier and more cost effective to install than the traditional nail down method.

The project engineer was impressed by the system’s ease of installation and ability to resist wind uplift.

Editor's Note: Scranton Gillette Communications and the SGC Infrastructure Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the Roads & Bridges' Editorial Team.