FIELD TEST RESULTS 



After the laboratory tests were completed, the R-Meter, Schmidt 

 hammer, and V-Meter were used to collect data during a recent inspection 

 (August 1984) of Pier J/K in San Diego, California (Ref 13). Ultrasonic 

 testing was performed using the V-Meter and data were collected with the 

 Schmidt hammer on selected piles to help assess the performance of these 

 instruments in the field. The R-Meter was also used to collect data for 

 assessing its performance. All of the instruments worked well during 

 the field evaluations. 



Background 



Pier J/K is an old concrete, pile-supported, waterfront structure, 

 located at the North Island Naval Air Station in b-an Diego. The pier is 

 supported by 791 piles and was built in three phases: 1921, 1930, and 

 1958. The 1921 construction (about 45% of the pier) used a combination 

 of 14- and 18-inch square conventionally reinforced piles. The 1930 

 construction (also about 45% of the pier) used 16-inch square conven- 

 tionally reinforced piles. The remaining 10% of the pier was constructed 

 in 1958 and it is supported on 16-inch octagonal prestressed piles. 



In 1981, this pier was inspected by Blaylock-Willis and Associates 

 of San Diego, under contract to the Ocean Engineering and Construction 

 Project Office (FP0-1) , Naval Facilities Engineering Command (Ref 14). 

 During this inspection, moderate to severe sulphate deterioration was 

 observed in all the concrete piles constructed in 1921 and 1930. The 

 inspection contractor speculated that Type I cement was used in those 

 piles; this type of cement has not been considered appropriate for salt 

 water use since around 1940. This inspection recommended that the pier 

 live load be restricted to 100 pounds per square foot and truck cranes 

 with capacities over 15 tons be prohibited. The contractor estimated 

 the remaining useful life to be no greater than 5 years. 



In 1984, FP0-1 again contracted with Blaylock-Willis, at the request 

 of the Naval Air Station, to reassess the condition of Pier J/K and update 

 their recommendations. During this inspection, NCEL personnel worked 

 with the contractor and FPO-1 to obtain NDT measurements on some of the 

 deteriorated concrete piles. Data were also collected on a few of the 

 1958 piles (which were in excellent condition) for comparison. The 

 overall results of this inspection confirmed the earlier findings. 



Before taking any NDT measurements, selected piles were thoroughly 

 cleaned by the contractor using the NCEL's high pressure water jet 

 cleaning system in conjunction with a rotary abrading tool attachment 

 ("Whirl Away"). Both the water jet and rotary abrading tool removed 

 some of the deteriorated surface area from the piles exhibiting 

 extensive sulfate attack. Where this happened, it was not possible to 

 obtain good NDT measurements using ultrasonics or the Schmidt hammer 

 because of the surface roughness. (Relatively smooth surface areas are 

 required to obtain good ultrasonic and Schmidt hammer data.) 



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