Retension

Retension is the act or process of restoring or increasing tension in a system that relies on tensioned elements. The term appears mainly in engineering, construction, and maintenance contexts and is often written as re-tension or retensioning.

In structural engineering, retensioning is performed on post-tensioned concrete members and cable-supported structures. Over time, tendons can lose tension due to creep, relaxation of materials, shrinkage, temperature effects, or settlement. Retensioning involves measuring current tendon tension against design values and applying controlled force with hydraulic jacks or tensioning devices at anchorages to restore the specified level.

In mechanical and industrial settings, retensioning applies to belts, chains, and other drive components. After installation or after stretching through use, the drive is re-tensioned to reduce slip, noise, and wear. Procedures typically include detensioning, readjusting to a recommended tension range, and re-tensioning with appropriate equipment.

In some contexts, retension may be used to describe re-establishing tension in other engineered systems, such as guy lines, cables, or textile reinforcements. The term is specialized and can be confused with retention (the act of keeping something in possession or memory) or with plain re-tensioning.