Click for next page ( 6


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 5
5 Table 1. Recommended test methods for measuring aggregate characteristics. Recommended Test Method Coarse Aggregates Fine Aggregates Shape, Angularity Shape Only Angularity and Texture Aggregate Imaging System Recommended Recommended (AIMS) University of Illinois Aggregate Recommended Image Analyzer (UIAIA) Multiple Ratio Shape Analysis Recommended Experimental Design and Statistical Analysis Ranking and Recommendation of Test Methods Aggregates were selected to cover a wide spectrum of origin, rock type, and characteristics. Three sizes of 13 coarse aggregate The Analytical Hierarchy Process (AHP) was implemented types and three sizes of five fine aggregate types were used in in a program and used to provide a ranking, or a priority list this study. Experienced individuals from the industry and high- of all the methods included in the evaluation. Criteria for the way agencies assisted in selecting and providing these aggregates preferred characteristics of test methods were developed and (photographs of representative samples of these aggregates used in the rankings. The AHP program provides flexibil- are provided in Appendix E). ity in defining the objectives, ranking criteria, and relative Statistically-designed experiments were conducted to eval- importance or priorities of the different criteria elements. uate repeatability, reproducibility, and accuracy of the selected Test methods recommended based on the AHP rankings are methods. Information about cost and operational character- listed in Table 1. istics was gathered from vendors, researchers, and operators A statistical-based methodology was developed to (1) sum- who are familiar with these systems. The operational charac- marize the analysis results, (2) facilitate the comparison between teristics of ease of use, portability, ability of interpreting data, the characteristics of different aggregate sources, and (3) classify readiness for implementation in central laboratories as well as aggregates based on the distribution of their characteristics. field laboratories, and applicability of test method to measure The methodology was presented in the form of macro-driven different aggregate types and sizes were considered. Microsoft Excel, a Visual Basic application.