Experimental Strain Responses of Posttensioning Tendon Anchorage Subjected to Prestressing Force Loss

Abstract

ABSTRACT

Prestress force is a key component of prestressed concrete structures. Early detection of prestressing force loss is necessary to ensure structural integrity and minimize long-term maintenance costs. This study presents an experimental investigation of strain responses in post-tensioning tendon anchorage subjected to prestressing force loss. To achieve the objective, first, a post-tensioning anchorage system is equipped with arrays of ESGs (electrical strain gages) for measuring strain responses. The anchorage system is installed on the stressing system, which is used to resist prestress force from the anchorage. Second, strain responses of ESGs arrays are measured under series prestress loss cases. Third, strain variations are utilized to determine stress components sensitive to prestress force loss. Last, empirical equations for prestress loss estimation is proposed based on experimental strain data. The result shows that strain responses in the anchorage are promising to be used for monitoring the health conditions of the anchorage system.

Keywords: Strain response; prestress loss; post-tensioning structure; damage detection.