【作者】 刘中琦；

【导师】 刘立新； 徐有邻；

【作者基本信息】 郑州大学 ， 结构工程， 2009， 硕士

【摘要】 预应力螺旋槽钢筋简称PC棒,是我国冶金行业新研制开发的用于预应力混凝土结构的新型钢筋。PC棒以中低碳低合金热轧盘条为母材,经少许冷拔或冷轧加工后进行调质处理,具有螺旋槽状的外形,其抗拉极限强度标准值可达到1530MPa,有很好的延性和韧性,填补了我国预应力钢筋强度级别中的中间强度等级。本文主要进行了预应力螺旋槽钢筋的材料力学性能及其在混凝土中的预应力传递长度研究。钢筋的材性试验证明,预应力螺旋槽钢筋这种钢筋具有与高强钢丝相当的力学性能,符合标准GB/T5223-2005的性能要求,可以作为预应力钢筋用于混凝土结构。但PC棒的强屈比和均匀伸长率略低于高强钢丝,延性相对不如后者。本试验反映的是预应力钢棒试生产的产品的情况,试验表明其质量有待改进。因此,必须改进和稳定生产工艺,提高产品质量(尤其是延性性能),PC棒才能在建筑结构工程中得到实际的应用。根据28个PC棒预应力构件的试验,分析了钢筋直径、放张位置、混凝土强度、张拉应力、保护层厚度、时效、横向配箍率等影响因素对预应力传递长度的影响,经统计回归得到了PC棒在混凝土中的预应力传递长度计算公式。根据PC棒外形几何参数的特点和粘结锚固性能试验研究的结果,在回归公式基础上提出建议公式。本课题为国家科技支撑计划课题“高强钢筋与高性能混凝土应用关键技术研究”(2007BAQ01053)子课题之一。更多还原

【Abstract】 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更多还原