| Prestressing reinforcement with helical flute (PC steel bars) is used in prestressing concret structure, which is a new type of prestressed tendons developed by our country's metallurgy department. PC steel bars is made from medium low-alloy and low-carbon green rod, which has been cold drawn or cold rolled and then quenched and tempered,has a helical flute's shape, it's limit tensile strength can reach 1530MPa,have good tensility and toughness , is a supplement to our country's pretesting reinforcement's strength level's middle levelIn this paper, we carried out the research about mechanical capability , especially the PC steel bars' transmission length in concrete. The mechanical capabiliity test proves that PC steel bars has comparative mechanical property with high-strength steel wire, and it in accordance to GB/T5223-2005 standard's function require , can be used as prestressing reinforcement in concret struction. But PC steel bars' tensile ratio and uniform elongation slightly lower than high-strength steel wire, and its tensility inferior to high-strength steel wire. This test reflects product quality of PC steel bars' preproduction, results indicates that PC steel bars' quality is need to improve. So, only through improve and steady production technology, improve product quality (especially in tensility), PC steel bar can get practical used in constructional engineering.According to 28 pre-tensioned members made of PC steel bars' test, the effect of diameter, The location of shear reinforcement, concrete strength, pretensioned force, concrete cover thickness and time-effect have been analyzed, by way of experimental statistical regression , the computing formula of PC steel bars' transmission length in concrete has been established. According to PC steel bars' shape's geometric parameter feature and bond-anchorage property test's results, we got the suggestion formula based on the computing formula... |
PDF Full Text Request