29 Sep 2025

Demonstration of Innovative Patching Technologies for Asphalt Pavement Sustainment

Abstract: iHMA and RapidPatch are two asphalt repair materials developed at the US Army Engineer Research and Development Center (ERDC) to provide asphalt patching materials that are readily available, support rapid return to traffic, and yield high quality, long-term performance solutions. The primary objective of this project was to complete multiple demonstrations of asphalt patching with iHMA and RapidPatch at four installations in different climate zones around the United States. These locations included Fort Wainwright (Alaska), Fort Drum (New York), Fort Huachuca (Arizona), and Bradshaw Army Airfield (Hawai‘i). Overall, demonstrations were completed successfully in all climates, providing an opportunity to evaluate patching technologies in real-world environments, some of which are considered untraditional conditions for repairing asphalt. In total, 111 tubes of iHMA and 90 buckets of RapidPatch were used to complete 55.3 ft3 and 49.8 ft3 of patching, respectively, with patch sizes ranging from 4 ft2 up to 20 ft2. Both iHMA and RapidPatch repairs performed well under accelerated trafficking at all installations, exhibiting no more than 6 mm of rutting (less than 1⁄4 in.) after 1,000 passes of heavy truck loading. After 9 to 12 months of operational traffic and environmental exposure, both iHMA and RapidPatch repairs have performed well.

6 Oct 2022

Development and Validation of a Balanced Mix Design Approach for CIR Mixtures Using Full-Scale Testing

Abstract: The main goal of this study was to improve the performance of cold in-place recycling (CIR) mixtures by using a balanced mix design (BMD) approach. This study involved preparing and testing CIR mixtures in the lab at varying contents of bituminous additives and constant content of 1% cement and 3% water. Eight combinations of CIR mixtures were produced for this study using two binders (emulsion and foamed asphalt), compaction efforts (30 and 70 gyrations), and curing processes (72 hours at 140°F and 50°F). Results showed that asphalt pavement analyzer, semicircular bend, and indirect tensile strength tests presented the highest correlation with the change of binder contents. The study successfully used the developed BMD for designing CIR mixtures and selecting their optimum binder contents. It then used three balanced CIR mixtures to construct full-scale pavement sections to validate the BMD approach in the field. A heavy vehicle simulator was used to apply different accelerated loadings on each section. Results showed that the CIR section with 2% binder presented the best rutting performance under truck loading and the highest rutting susceptibility under aircraft loading. Conversely, the CIR section with 3% binder presented the highest cracking resistance under both truck and aircraft loading.