配置高强钢筋的UPC梁预应力筋极限应力增量试验研究

Experimental Study on Ultimate Stress Increment of Prestressed Tendons of UPS Beams with High Strength Reinforce Steels

为了研究配置高强钢筋的UPC梁的预应力筋极限应力增量的影响因素,进行了9根UPC试验梁静载试验。试验结果表明,配置HRB500级非预应力钢筋的UPC梁的预应力筋极限应力增量随HRB500级非预应力筋配筋率的提高而降低;相对低强度等级的非预应力筋,HRB500级钢筋作为非预应力筋能提高UPC梁的预应力筋极限应力增量,且预应力筋为抛物线型布置的UPC梁的极限应力增量大于预应力筋直线型布置时的值;非预应力钢筋采用高等级钢筋时,按JGJ92-2004《无粘结预应力混凝土结构技术规程》给出的公式计算无粘结预应力筋极限应力增量值偏于安全。

In order to investigate the influence factor of ultimate stress increment of prestressed tendons of the UPC beams with high strength reinforced steels, 9 UPC beams are designed for the static load test. The research results show that ultimate stress increment of prestressed steel of UPC beams with HRB500 reinforced bars decreases with the increas-ing of the reinforcement ratio of HRB500 reinforced bars; Compared with low intensity grades of non-prestressed rein-forcement, HRB500 reinforced bars as a prestressed reinforcement can improve the ultimate stress increment of pre-stressed steel of UPC beams, and ultimate stress increment of prestressed steels arrangement as parabolic type of UPC beams is greater than that of the linear arrangement of prestressed reinforcement; ultimate stress increment of unbounded prestressed tendons should be safe according to the formula from the JGJ92-2004 ＆quot;Technical specification for concrete structures prestressed with unbounded tendons＆quot;.