I have thought about this question for a long time and found that I have written thousands of words. You copied the paper directly. For your own good, look up the information and cook slowly.

Give you a few hints:

1. Reinforcement tensioning can improve the partial strength of reinforcement and reduce the deformation of reinforcement in tension. There is a picture in mechanics of materials, which is very useful.

2. Steel bars can be saved. The tensile specification of steel bars has allowable tensile values. If it is stretched, it will be saved naturally. If it is overstretched ... don't.

3. One of the tensile tests is to detect the strength and ductility of steel bars, determine the tensile range of steel bars, and detect the quality of steel bars (sometimes peeling and cracking will occur when the quality of steel bars is poor).