01047003

Monograph

http://onlinepubs.trb.org.../NCHRP109_Final_Report.pdf

This Innovations Deserving Exploratory Analysis project developed a new nondestructive method for the condition evaluation of fiber-reinforced polymer (FRP) concrete bridge members using small antenna array to detect microwave signals. Work in the initial stage focused on specifications development for frequency range, scan interval, coverage area and other mechanical properties of the proposed antenna system. The configuration and the optimum number of array antennas were also established. The system consists of three modules: a controller and a power supplier, a transceiver, and array antennas with a feed network. An embedded single board computer with a data acquisition board was used as the controller. The design of the power supply was modified to minimize its size. A transceiver with several RF parts was assembled that included filters, power amplifiers, attenuators and detector. The design of the smart antenna system was finalized. The housing design was also improved and refabricated. The software for system operation and real-time data processing and image visualization was developed and integrated with the hardware. The software verified that the feed network was working well and the control parameters were correct. The software program can control the parameters for the transceiver operation and parameters for beam scanning and also diagnose the status of the system. Work in the final stage focused on performance evaluation of the prototype on a variety of concrete-FRP specimens. Debonds of various areas and gaps were artificially created between the FRP and concrete. The prototype was shown to be effective in detecting and even quantifying the debonding at the concrete-FRP interface.

This NCHRP-IDEA investigation was conducted by Newport Sensors, Inc., Irvine, California. 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

TRB-NCHRP-109

English

33p

2007-1

NCHRP-IDEA Program Project Final Report

Final Report

January 2005 - October 2006

Print

Figures; Photos; References; Tables (2)

Bridge members; Debonding; Fiber reinforced plastics; Housings; Jacketing (Strengthening); Microwave detectors; Nondestructive tests; Phased arrays; Prototype tests; Software; Specifications; Technological innovations

Innovations Deserving Exploratory Analysis (IDEA) (Program)

Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls

TRIS, TRB

Apr 26 2007 9:25AM