Unclassified 



SECURITY CLASSIFICATION OF THIS PAGE (When Dele 



'.niered) 





REPORT DOCUMENTATION PAGE 



READ INSTRUCTIONS 

 BEFORE COMPLETING FORM 



1. REPORT NUMBER 



TN-1747 



2. GOVT ACCESSION NO. 



DN987077 



3 RECIPIENT'S CATALOG NUMBER 



4. TITLE (end Subtitle) 



UNDERWATER NONDESTRUCTIVE TESTING OF 

 CONCRETE: AN EVALUATION OF TECHNIQUES 



5. TYPE OF REPORT & PERIOD COVERED 



Interim: Oct 1983 - Sep 1984 



6 PERFORMING ORG. REPORT NUMBER 



7. AUTHORfs; 



A. P. Smith 



8. CONTRACT OR GRANT NUMBER(s) 



9. PERFORMING ORGANIZATION NAME AND ADDRESS 



NAVAL CIVIL ENGINEERING LABORATORY 

 Port Hueneme, California 93043 



10. PROGRAM ELEMENT. PROJECT, TASK 

 AREA & WORK UNIT NUMBERS 



63725N; 

 YO995-01-004-310A 



1 1. CONTROLLING OFFICE NAME AND ADDRESS 



Naval Facilities Engineering Command 

 Alexandria, Virginia 22332 



12 REPORT DATE 



February 1986 



13 NUMBER OF PAGES 



64 



14 MONITORING AGENCY NAME » ADDRESSfif dillerent tram Controlling Oilier) 



15. SECURITY CLASS (ol this report) 



Unclassified 



15a. DECLASSIFICATION DOWNGRADING 

 SCHEDULE 



16. DISTRIBUTION STATEMENT (oi this Report) j 



Approved for public release; distribution unlimited. 



17- DISTRIBUTION STATEMENT (ol the abstract entered in Block 20, il dillerent trom Report) 



18 SUPPLEMENTARY NOTES 



19 KEY WORDS (Continue on reverse side il necessary end ident-ly by block number) 



Underwater inspection, nondestructive testing, waterfront facilities, concrete, Schmidt 

 hammer, rebar location, ultrasonic testing 



20 ABSTRACT (Continue on reverse side II necessary end identity by block number) 



Three commercially available instruments for testing concrete above water were 

 successfully modified for underwater use and evaluated in laboratory and field tests. One 

 of the three instruments was a magnetic rebar locator that locates rebar in concrete struc- 

 tures and measures the amount of concrete cover over the rebar. Another instrument was a 

 Schmidt hammer that evaluates the surface hardness of the concrete and obtains a general 



continued j 



DD | JAN M 73 1473 EDITION OF 1 NOV 65 IS OBSOLETE 



Unclassified 



SECURITY CLASSIFICATION OF THIS PAGE (When Dele Entered) 



MBL/WHOI 



D 0301 00M0215 5 



