Central Iowa Expo Pavement Project: Phase IV Performance Assessment Experimental Test Plan_ TR-817

Approximately 4.8 miles of roadways at the Central Iowa Expo facility in Boone, Iowa, were reconstructed in 2012 as part of Iowa Highway Research Board (IHRB) project TR-671. The project included three phases encompassing construction and field testing to assess the performance of several pavement foundation technologies. The Iowa Department of Transportation (DOT) has approved a Phase IV project to assess the long-term performance of the pavements evaluated in Phases I through III. This report provides recommendations for two experimental test plan alternatives for Phase IV, one outlining a minimum recommended scope and another outlining a comprehensive scope to more precisely quantify differences among test sections. The overall goal of the testing program is direct measurement of not only the in situ mechanistic input parameters necessary for AASHTOWare Pavement ME Design but also the impacts of seasonal variations in the measurement values. The report includes a statistical analysis of the data from Phases I through III and, based on this analysis, recommendations regarding the specific sections to test as well as the number and type of tests to perform. The methods proposed for Phase IV field testing include automated plate load testing, core hole permeability testing, and dynamic cone penetrometer testing. The report also summarizes engineering measurement values to be obtained for each test. Tests will be conducted in fall 2023, spring 2024, fall 2024, and spring 2025