What is the minimum and maximum initial force for strand jacking of the final tensioning force?

The correct choice indicates that the minimum and maximum initial force for strand jacking of the final tensioning force is between 5% and 25%. This range is critical in the context of strand jacking, a technique commonly used in post-tensioning applications where cables or strands are initially tensioned to back up the process of lifting or adjusting structures.

This percentage range is intended to ensure that the strands are properly tensioned without exceeding or understressing them too much, thereby maintaining structural integrity. A minimum of 5% ensures that there is enough initial force to engage the strands effectively, whereas a maximum of 25% prevents excessive strain that could lead to damage or failure of the materials being used.

Understanding this range is essential for engineers and construction professionals to ensure safe handling and tensioning of strands during the jacking process, which translates into successful outcomes in construction projects.