Effect of Aggregate Properties on Abrasion Resistance of Airfield Pavements

Abstract: Abrasion resistance is a critical factor in ensuring the safety and operational efficiency of airfield pavements, particularly under varying weather conditions. The texture of the pavement surface, including macrotexture and microtexture, plays a significant role in controlling abrasion resistance. Therefore, appropriate selection of aggregates is critical in maintaining adequate abrasion resistance. The overall goal of the study is to develop a statistical model to predict abrasion resistance measured using Micro-Deval Abrasion (MDA) values of coarse aggregates. For this purpose, aggregate samples were collected nationwide from ten sources. The significance of this study lies in its focus on selecting aggregate properties to provide adequate abrasion resistance, which will be critical for the designers to use these aggregates in flexible and rigid mixtures. The experimental plan for assessing aggregate properties included a range of tests, namely X-ray fluorescence spectrometry (XRF), Los Angeles Abrasion (LAA), MDA, soundness, Accelerated Polishing Machine (APM), and British Pendulum Tester (BPT). The chemical compounds within the aggregates makeup were obtained by XRF. The aggregate deterioration was evaluated using the LAA test, and the capability to resist wet environment abrasion was measured by the MDA test. The long-term durability characteristics of aggregates were determined using the soundness test. The polishing behavior of aggregates was studied by conducting an APM test as an indicator of abrasion resistance. The aggregate surface friction was then measured using the BPT in terms of British Pendulum Number (BPN) value. Finally, a multi-linear regression analysis was developed to predict the MDA values for coarse aggregates based on their chemical composition (e.g., Fe2O3 and MgO) and mechanical properties (e.g., LAA). Results of the XRF test showed that chemical compounds (higher SiO2, higher Al2O3, and lower CaO proportions) are an indication of potential abrasion resistance of aggregates. The outcomes of the LAA test for the aggregate types, including limestone and dolomite, observed identical mass loss in their varying nominal maximum aggregate sizes (NMAS) compared to other aggregate types. Out of ten sources, 42% showed average LAA test values ranging from 20% to 30%. Only 29% of the aggregate sizes had average LAA test values below 20% mass loss and were considered to perform better in abrasion resistance.
Furthermore, the results of the MDA test for both coarse and fine aggregates were between 5% and 25%. However, aggregate sources with MDA test values averaging below 10% mass loss are considered acceptable in terms of wear resistance. The results of the soundness test showed that all the aggregate sources had less than 15% mass loss, which is considered adequate for long-term durability. The hourly polishing behavior of coarse aggregates was performed, and the aggregate surface friction was determined for each aggregate source and reported as BPN value. Overall, a statistical model was developed to predict the MDA values of coarse aggregates based on their mineral compositions and mechanical properties to identify the aggregates to be used in flexible and rigid mixtures.