基于抗裂性要求的预应力筋配束方法研究

针对现有的预应力结构中预应力筋的配束方法,根据《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTG D62-2004)及《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTJ023-85)对预应力结构使用性能的规定,分别按抗裂性要求和应力条件给出了两种对预应力筋进行数量估算的公式。通过实桥算例,结果表明按应力条件估算的预应力筋数量小于按抗裂性要求估算的预应力筋数量,相差幅度最大达到21%,若按应力条件估算预应力筋的面积且实际富足量有限,就会导致截面不能满足抗裂性要求。

Study on Reinforcing Method of Prestressed Reinforcement Based on Requirement of Cracking Resistance

According to Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts(JTG D62-2004)and Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts(JTJ023-85)for the regulation of prestressed structure using performance,aiming at the existing reinforcing method of prestressed reinforcement in the prestressed structure,two kinds of formulas for the quantity estimation of prestressed reinforcement are presented according to cracking resistance requirement and stress condition separately.The analyzing result of an actual bridge indicates that the quantity of prestressed reinforcement to be estimated on the stress condition is less than that on the requirement of cracking resistance.The maximum D-value is 21%,otherwise,the requirement of cracking resistance would not be fulfilled if estimating the area of prestressed reinforcement on the stress condition and supply with limited affluence.