A study on waterproof case of Schmidt hammer for measurement of underwater concrete structures

The majority of port facilities are decreasing in durability such as corrosion due to salt damage of concrete structures. Therefore, the importance of compressive strength management and diagnostic technology of underwater structures is increasing day by day. While the development of high-precision test equipment on land has been quite established, on the other hand the test equipment for underwater usage are still limited. For example, there has video footage and thickness measuring gauge. Rebound hardness measurement methods using Schmidt hammer case for nondestructive inspection of land concrete structures are mostly utilized. Using the test equipment on land and in underwater, could be an advantage for its convenience. For that reason, we evaluate a waterproof case of commercial Schmidt hammer, by comparing its performance on land and on in underwater test. From this study, we produced a waterproof case to be used for the commercial Schmidt hammer in underwater. Further we suggest an empirical equation as a comparison results between common Schmidt hammer and waterproofed system.