Evaluation of prestressing steel stress at ultimate limit state

Abstract EN

Due to the advancement of using limit state methods in designing prestressed concrete structure, there is a need to establish a simple and fairly accurate approach to determine the ultimate stress in the prestressing steel.

In this paper an exponential expression is utilized for defining stress-strain curves of prestressing strands.

The resulting curves of the exponential expression combined with compatibility expressions are used for evaluating the steel stress at ultimate state in bonded prestressed concrete sections.

This is achieved either by utilizing an iterative approach and small programmable calculators or a specially developed nomograph to facilitate the computations.