Evaluation of Gap-Graded Asphalt Concrete Mixtures Part II: Statistical Design and Analysis, HR-157, 1973

(1973) Evaluation of Gap-Graded Asphalt Concrete Mixtures Part II: Statistical Design and Analysis, HR-157, 1973. Transportation, Department of


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This report presents the results of a comparative laboratory study between well- and gap-graded aggregates used in asphalt concrete paving mixtures. A total of 424 batches of asphalt concrete mixtures and 3, 960 Marshall and Hveem specimens were examined. The main thrust of the statistical analysis conducted in this experiment was in the calibration study and in Part I of the experiment. In the former study, the compaction procedure between the Iowa State University Lab and the Iowa Highway Commission Lab was calibrated. By an analysis of the errors associated with the measurements we were able to separate the "preparation" and "determination" errors for both laboratories as well as develop the calibration curve which describes the relationship between the compaction procedures at the two labs. In Part I, the use of a fractional factorial design in a split plot experiment in measuring the effect of several factors on asphalt concrete strength and weight was exhibited. Also, the use of half normal plotting techniques for indicating significant factors and interactions and for estimating errors in experiments with only a limited number of observations was outlined,

Item Type: Departmental Report
Keywords: Aggregates, Asphalt concrete, Calibration, Compaction, Errors, Evaluation, Gap grading, Laboratory studies, Measurement, Statistical analysis, Strength of materials
Subjects: Transportation
Transportation > Materials
Transportation > Materials > Gravel and aggregates
Transportation > Roads and highways
Transportation > Data and Information Technology
ID Code: 19631
Deposited By: Iowa DOT Library
Deposited On: 01 Jun 2015 15:06
Last Modified: 11 Aug 2015 16:12
URI: https://publications.iowa.gov/id/eprint/19631