This durability survey investigates age-related changes in the properties of pile materials such as concrete and reinforcing steel when reusing existing piles, but this is limited to confirming that the results satisfy the regulations and specifications in the design documents. In this paper, the survey results of existing cast-in-place piles are analyzed for the purpose of utilizing the survey results to rationalize pile reuse design. As a result, we gain an understanding of the trends in compressive strength, density, elastic modulus and neutralization depth, and present the results of the study on evaluation of pile properties for use in design.
