31 Jan 2024

Verification of Current Los Angeles (LA) Abrasion Test Criterion for Aggregate Degradation in Airfield Asphalt Pavements

Abstract: Low-quality mineral aggregates can potentially lead to production, construction, and long-term performance-related problems in asphalt concrete pavements. Therefore, effective qualification criteria for mineral aggregates are paramount. This study was performed to investigate the effectiveness of the Los Angeles abrasion (LAA) test to assess the abrasion resistance of coarse aggregates commonly used in airfield asphalt paving. The LAA test acceptance criteria currently specified by state departments of transportation were examined and compared to the current Department of Defense criterion. Additionally, recent experiences during a forensic evaluation to identify potential sources of excessive presence of foreign object debris on an airfield runway are also briefly discussed in this report. The LAA test and associated acceptance criterion in Unified Facilities Guide Specification (UFGS) 32 12 15.13 were evaluated by testing 24 aggregate sources from various US locations. Also, the Micro-Deval abrasion test was performed as a surrogate abrasion resistance test. Sufficient evidence was not found to suggest adjustments to current LAA test criterion or to recommend the use of an alternative abrasion test. The current UFGS specifications should be improved to provide a more thorough aggregate testing protocol and detailed guidelines regarding aggregate sampling and testing frequency during design and construction of asphalt pavements.

10 Jun 2020

PUBLICATION NOTICE: Investigation of Materials for Charleroi Lock and Dam Monongahela River Reconstruction Project

Abstract: The investigation described in this report was conducted for the U.S. Army Engineer District, Pittsburgh as part of a preliminary investigation of cementitious materials and concrete design pursuant to construction of Charleroi Lock and Dam Monongahela River Reconstruction Project. Local materials provided to the U.S. Army Engineer Research Development Center (ERDC) for testing included three different coarse aggregate gradations, two fine aggregate sources, a type II (MH) cement, four fly ash sources, a slag cement, a silica fume, a limestone powder, five admixtures, and two water sources. Aggregate tests consisted of sieve analysis, specific gravity, absorption, materials finer than No. 200, organic impurities, soundness, LA abrasion, clay lumps and friable particles, flat and elongated particles, lightweight particles, and petrography. All cementitious, admixtures, and water-source materials were tested for chemical and physical properties based on appropriate specifications. In addition, four mixture proportions developed by the ERDC for this project in 2005 were scaled to determine the early stiffening of mortar, freezing and thawing, and heat of hydration. This report presents the material characteristic results determined by laboratory testing in accordance with American Society for Testing and Materials procedures or regulating specification criteria.