预应力混凝土应用及减少预应力损失措施

Application of Prestressed Concrete and Methods for Reducing Prestress Loss

以安徽某库房工程预制排架结构为例,介绍了预应力混凝土施工中的底模施工、锚具加工、预应力钢筋制作、孔道留设、预应力钢筋张拉、预应力值校核以及孔道灌浆等施工工艺。指出锚具变形、预应力筋与孔道间摩擦、应力松弛、混凝土收缩徐变等均会引起预应力损失,针对此,提出了超张拉、合理养护等预防措施。

Taking precast bent structure of some storehouse in Anhui for example,some construction techniques of prestressed concrete are introduced,such as construction of bottom formwork,anchorage processing,fabrication of prestressed steel bars,setting-up hole,tension of prestressed steel bars,checking of prestressed values and pouring for hole.It is pointed out that some factors,which are the deformation of anchorage,friction of prestressed steel bar and pole,prestress relaxation and shrinkage and creep of concrete,can induce prestress loss.According to these factors,some precaution methods are put forward,such as ultra tension and proper maintenance.