Demonstration of Innovative Technologies for Pavement Foundation Layer Construction: Pavement Foundation Mapping Projects - TPF-5(478)

The Iowa Department of Transportation has recognized that the current level of performance from their pavements is not financially sustainable which has motivated the Iowa DOT to develop practical steps that will result in a lower ownership cost for their pavement infrastructure and increase their level of service to the public. The Iowa Department of Transportation believes that the next step forward in pavement foundation construction quality as well as optimized pavement designs will be realized by implementing design-value, modulus-based assessment and ensuring that the pavement design assumptions are met during construction. The FHWA has also recognized the need to improve the quality of pavement foundations nationally and has identified this need as a focus area in their 2019/2020 annual report to Congress on the Accelerated Implementation and Deployment of Pavement Technologies, AID-PT program. In recognition of this need the FHWA established Transportation Pooled Fund Project TPF-5(478) entitled: Demonstration to Advance New Pavement Technologies Pooled Fund. In 2022, The Iowa DOT joined the study and submitted a proposed project “Support for Pavement Foundation Design Modulus Verification and Construction Quality Monitoring” which was accepted to provide support for piloting and implementing modulus-based pavement foundation construction. To meet the project objectives, modulus-based verification technology was used on five (5) Iowa DOT projects during the 2022 construction season. The focus of the study was to collect material-specific pavement foundation support values to advance Iowa’s mechanistic pavement design process. This report summarizes data and lessons learned from these mapping projects