About our Sessions

Expansive soil subgrades have been detrimental to the performance of roadways, especially in Central Texas region. Specifically, roadway failures in the form of longitudinal cracks and heaves along the roadway are developed most often due to extensive volumetric changes resulting in high swell-shrink behavior of subgrade soils. Such roadway failures increase the maintenance intervals and associated costs, often proving to be a burden to roadway maintenance agencies. A case history on the use of geosynthetic interlayers to minimize longitudinal and reflective cracks along the Texas State Highway (SH) 21 in Austin district is presented. The SH21 roadway comprised a 6-inch-thick asphalt layer, placed over a 6-inch-thick cement treated base and a 9-inch-thick lime stabilized subbase founded on an expansive subgrade soil. Consequently, distresses in the form of longitudinal cracks, heaves, rut along the wheel path necessitated the Texas Department of Transportation (TxDOT) to develop a rehabilitation program to restore roadway serviceability in Summer 2019. TxDOT’s rehabilitation program comprised repairing the existing roadway surface, applying binder tack coat, installing geosynthetic (polymeric composite) interlayer, and finally constructing 3-inch-thick asphalt overlay. The rehabilitation program proved to be successful in minimizing longitudinal cracks, heaves, and other distresses. Specifically, evaluations from May 2025 revealed no sign of distresses along the SH21 roadway, since their rehabilitation in October 2019. Overall, it can be concluded that the rehabilitation program minimized distresses and thereby reduced the annual maintenance interval and associated costs.

The Presentation includes the following learning objectives:

• Learn how you can enhance your career by pursuing certification as a Value Methodology Associate (VMA) or Certified Value Specialist (CVS).
• Learn how to apply divergent or creative thinking skills to a guided group effort charged with finding ways to improve a project, product, or process.
• Learn how to collaborate with a wide variety of professionals with different backgrounds and differing views on how to approach engineering scenarios to realize significant cost savings. The presentation will review each of the six phases of a Value Engineering Study.