ASTM_D_4788_-_03_2013.pdf

Designation:D478803(Reapproved 2013)Standard Test Method forDetecting Delaminations in Bridge Decks Using InfraredThermography1This standard is issued under the fixed designation D4788;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of delamina-tions in portland-cement concrete bridge decks using infraredthermography.This test method is intended for use on exposedand overlaid concrete bridge decks.1.2 A Precision and Bias statement has not been developedat this time.Therefore,this standard should not be used foracceptance or rejection of a material for purchasing purposes.NOTE1This test method can be used on asphalt or concrete overlaysas thick as 4 in.(100 mm).1.3 This test method uses an imaging infrared scanner andvideo recorder,mounted on a vehicle,to detect delaminationsand debonded areas on bridge decks and to record theinformation.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D4580 Practice for Measuring Delaminations in ConcreteBridge Decks by Sounding3.Summary of Test Method3.1 The vehicle-mounted infrared scanner and video re-corder is driven over the center of each lane of a bridge deck.The data from the scanner is recorded on video tape.Delami-nations appear as white or“hot areas on a gray or“coolerbackground in the video image on a monochrome scannersystem during daytime testing.During nighttime testing,thedelaminations will appear as dark or“cooler areas on a whiteor“warmer background.Delaminations will appear as thewarmer colors on color scanner systems during daytimetesting.Calibration of thermal anomalies using sounding tech-niques are used to determine the colors associated withdelaminations.3.2 The conventional video image is used to edit theinfrared image and separate those patches or surface defectsthat may be present and may appear as hot areas.3.3 The video recording is used to map the delaminatedareas at a suitable scale.4.Significance and Use4.1 This test method may be used in conjunction with othertest methods in determining the general condition of a bridgedeck.4.2 Areas indicated as delaminated on overlaid bridge decksmay be an indication of lack of bond between the overlay andthe underlying bridge deck.This test method may be used indetermining specific areas of delaminations requiring repair.5.Apparatus5.1 GeneralIn order to collect data on the areal extent andlocation of the delaminations,the following apparatus isrequired:5.1.1 Infrared Scanner An imaging infrared scanner hav-ing a minimum thermal resolution of 0.2C under ambient airconditions.The scanner shall be mounted on the front of thevehicle at a height sufficient to allow a minimum image widthof 14 ft(4.3 m).The scanner shall be capable of producing atelevision-compatible image.5.1.2 Video Recorders capable of reproducing a thermalimage or a conventional video image.Each device shall have atleast one audio channel available and provide a minimumresolution of 240 lines per inch.Two are required.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.32 onBridges and Structures.Current edition approved Sept.1,2013.Published November 2013.Originallyapproved in 1988.Last previous edition approved in 2007 as D4788 03(2007).DOI:10.1520/D4788-03R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.3 Video CameraAconventional video camera capableof viewing a minimum image of 14 ft(4.3 m)and producing acolor video signal that can be recorded on a standard videorecorder.5.1.4 Distance Measuring Device having an accuracy of 63in.(76 mm)over the longest span in the deck.The output ofthis device shall be recorded by both the infrared videorecorder and the conventional video recorder.5.1.5 Test Vehicle on which the imaging infrared scannerand video recorder will be mounted.The vehicle shall becapable of supporting the infrared scanner and the conventionalvideo camera at a hei