A Coring Method for the Nondestructive Evaluation of Effective Prestress Force in Prestressed Concrete Structures

Prestress forces are often applied to concrete structures to create compressive stresses in regions that will be subjected to superposed tension stresses due to applied service loads. Often these prestress forces are applied using steel tendons that are imbedded in the structure and stressed in tension. The tendons react against the structure and thus subject the concrete to compression. The structure may be fully-pre-stressed, so that the precompressed regions remain in compression under applied service loads, or partially-prestressed so that the precompressed regions may experience tension stress under applied service loads. Additional details of the mechanics of pre-stressed concrete members can be found in many textbooks (e.g. Reference [1])