... :GB,ASTM 4.Used for: railway and highway bridge, roof truss Prestressed Concrete Steel Wire 1.Diameter:4.0mm~7.0mm2 ... .Standard:GB,ASTM4.Used for: railway and highway bridge, roof truss High strength, low slack, delivered in coils, proper length, low ... -tensioning methods, e.g. major railway and highway bridge, roof truss, crane beam, prefabricated slab for industrial and civil construction,wall ...