Thereby difficult problem that we test relaxation ratio of prestressed concrete steel wire for 1000 hours has been solved.
此法成功地用于生产中，从而解决了预应力钢丝1000小时松弛率检验的难题。
2
Prestressed steel wire and strand for bridge are used in the condition of high alternating stress with humidity atmosphere and sometime seawater atmosphere, which speed up the corrosion.
The materials′properties of prestressed steel wire post high temperatures were studied by experiments and various cooling patterns were considered in the experiments.