Bridge-Elastic Shortening of Concrete

During the stressing of tendon, the concrete may experience elastic shortening. This causes the stress loss in the tendon installed prior to this.

In pre-tensioning, all strands are anchored simultaneously. Thus, elastic shortening of concrete is caused by full prestress force, and all the tendons should have similar degree of loss due to the shortening of concrete.

In post-tensioning however, tendons at any section experience different level of stress loss, dependent of the sequence of stressing. In this case, it is usually sufficient to determine the average stress loss and apply to all tendons.