Aggregate Imaging Measurement System 2 (AIMS2): Final Report

Federal Highway Administration2011PDFTech ReportMasad, EyadGates, LesliePyle, RogerBushee, DavidPine Instrument CompanyUnited States. Federal Highway Administration. Office of InfrastructureByrd, FreidaZirlin, JulieFederal Highway Administration (U.S.)United StatesImage analysisAggregates by shape and surface textureHot mix asphaltHydraulic cementFHWA-HIF-11-030DTFH61-08-G-00003Freida Byrd;Julie ZirlinFinal ReportAs part of a national initiative sponsored by the Federal Highway Administration under the Highways for LIFE program, Pine Instrument Company was awarded a grant to improve the design of the research instrument to analyze aggregate properties using digital imaging technology, conduct a ruggedness study on the new design, perform an interlaboratory study, and evaluate the potential commercial viability of the new instrument. This final report outlines the work and conclusions of this project. Current methods for determining the characteristics of aggregate shapes, which influence the structural performance of asphalt design, hydraulic cement concrete, and unbound aggregate pavement layers, are difficult, timeconsuming, and subjective. This report describes a project to improve the design of the Aggregate Image Measurement System 2 (AIMS2), which uses a variable magnification microscope-camera system and two different lighting configurations to capture aggregate images for analysis and software with the ability to objectively quantify aggregate shapes on the macro and micro scales. Also reported are the results of a ruggedness study on the improved design, an interlaboratory study, and an evaluation of the commercial viability of the new instrument. Comparison testing showed that the AIMS1, the research prototype, and the AIMS2 provided similar ranking of aggregates and comparable results. Ruggedness testing validated that operating parameters were appropriately controlled and provided reproducible results. The interlaboratory study, which involved 32 laboratories, found that AIMS2 outputs have reasonable coefficients of variation for all sizes of aggregate excepting the 0.075-mm size. The project demonstrated that AIMS2 can provide objective and reproducible shape characterization of aggregates. Considerable interest in the AIMS2 has been demonstrated in the United States and other countries, and marketing is being pursued by the manufacturer.104