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Title:

CONCRETE EVALUATION BY RADAR THEORETICAL ANALYSIS

Accession Number:

00368278

Record Type:

Component

Availability:

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Order URL: http://worldcat.org/isbn/0309033578

Abstract:

The operating principles of a mobile high-resolution radar system that has been optimized for inspection of pavements such as highways, bridge decks, and runways are described. The waveforms generated by the high-resolution radar are illustrated as well as the interaction of these waveforms with the pavement structure. Graphic derivations of representative radar waveforms for varying conditions are shown by using time-domain analysis. This simplified method of analysis enables useful models to be made for a range of separation thicknesses and pavement base materials. The results of laboratory tests are presented in which radar illuminates a double slab of concrete and the spacing between the two slabs is varied discretely and precisely from 0 to 30 cm (o 10 12 in). For spaces up to 7.5 cm (3 in) between two similar materials, the amplitude of the radar echo appears to be nearly proportional to the same dimension. As the space increases to 15 cm (6 in), the signal increases primarily in width. For spaces greater than 15 cm, the radar signal splits into two separate waveforms, thereby resolving the upper and lower boundaries of the space. These laboratory data are related to in situ void data taken on airport runways. Finally, a detailed analysis of a single concrete slab, illuminated by the radar, is performed. The amplitude and phase properties of the reflected signal waveforms are derived independently based on time-delay measurement and a mathematical method. Both methods agree with each other and with the experimental data. (Author)

Supplemental Notes:

Publication of this paper sponsored by Committee on Performance of Concrete. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.

Monograph Accession #:

01411656

Authors:

Alongi, A V
Cantor, T R
Kneeter, C P
Alongi Jr, A

Pagination:

pp 31-37

Publication Date:

1982

Serial:

Transportation Research Record

Issue Number: 853
Publisher: Transportation Research Board
ISSN: 0361-1981

Conference:

61st Annual Meeting of the Transportation Research Board

Location: Washington District of Columbia, United States
Date: 1982-1-18 to 1982-1-22

ISBN:

0309033578

Media Type:

Print

Features:

Figures (11) ; References (5)

Old TRIS Terms:

Subject Areas:

Bridges and other structures; Highways; Materials; Pavements; I32: Concrete

Files:

TRIS, TRB

Created Date:

Dec 30 1982 12:00AM

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