Application of LADAR in the analysis of aggregate characteristics
By: Linbing Wang ... [et al.].
Contributors: National Research Council (U.S.). Transportation Research Board; National Cooperative Highway Research Program; American Association of State Highway and Transportation Officials; United States. Federal Highway Administration
Series: NCHRP report -- 724; Report (National Cooperative Highway Research Program) -- 724.
Publisher: Transportation Research Board
Published: 2012
Place of publication: Washington, D.C
Language: eng
Number of pages: 86
ISBN-13: 9780309258456
Subjects: Aggregates (Building materials); Measurement; Optical radar; Laser radar; Cables
Description: "NCHRP Project 4-34, 'Application of LADAR in the Analysis of Aggregate Characteristics,' was conducted by Virginia Polytechnic Institute and State University, Blacksburg, Virginia, with participation by the University of Illinois at Urbana-Champaign.  The objective of the project was to develop and evaluate a laser detection and ranging  (LADAR) system capable of precise and accurate measurement of the aggregate characteristics of shape, volume, angularity, surface texture, specific surface area, and volumetric gradation. Ideally, the final system would be applicable to aggregate in three size categories--coarse (2 in. to #4), fine (#4 to #200), and microfine (P200)--and suitable for  routine use in research, central, and field laboratories for Portland cement concrete and  asphalt concrete mixture design and quality assurance.  The project, which developed new equipment and computer algorithms, proved technically challenging. The project team developed a prototype Fourier transform interferometry (FTI) system with fully functional hardware and software. The system can characterize aggregate shape, angularity, texture, surface area, and volume of a wide range of aggregate  sizes with high accuracy. Assembly and operation of the FTI system consisting of a chargecoupled device (CD) camera, a fringe source, a sample platform, and a software package are fully documented in the report.  The accuracy and precision of the prototype FTI system are comparable to or better than  those of other systems now available to automatically measure aggregate characteristics,  but its current range of aggregate size--3/4 in. to #50--is narrower than desired.  Extending this size range is possible in the future by using a CCD camera with a larger field of view and increasing the system resolution through appropriate selection of the equipment components."
Notes: At head of title: National Cooperative Highway Research Program

Appendices A through J are available at http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP04-34_NR724AppendixesAE-J.pdf

Includes bibliographical references (p. 71).

Report also available online.

Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration NCHRP project 04-34