高层建筑中预应力混凝土梁技术应用分析
2012-06-04幸禹田
幸禹田
摘要:现代建筑中,为了满足建筑功能的需要,往往需要大跨度、大空间,普通混凝土梁无法满足大跨度带来的抗裂、抗弯要求。有黏结预应力技术可以解决大跨度混凝土梁的挠度和抗裂问题,同时也大大减小混凝土梁的截面尺寸和混凝土及钢筋的用量,提高了结构的使用空间,降低了工程造价。文章结合实际工程介绍了后张有黏结预应力混凝土梁的施工工艺和质量控制措施,为施工人员掌握后张有黏结预应力混凝土梁施工技术提供了参考。
关键词:高层建筑;预应力;混凝土梁;施工技术
Abstract: the modern architecture, in order to meet the needs of the building function, often need big span, large space, ordinary concrete beams can''t satisfy large span of crack, bring bending requirements. Have unbond prestressed technique can solve big span concrete beam and the deflection of crack and, at the same time, also greatly reduce the section size of concrete beams and the dosage of concrete and reinforced, improve the structure of the use of space and reduce project cost. Based on the engineering practice, introduces unbond prestressed concrete beam pieces of the construction technology and quality control measures for construction personnel master pieces after unbond prestressed concrete beam construction technology provides the reference.
Keywords: high building; Prestressed; Concrete beam; Construction technology
中图分类号: TU528.571 文献标识码:A 文章编号:
1工程概况
重庆某高层建筑施工中,其二层、屋面层局部大跨度梁使用了黏结预应力混凝土梁结构,预应力梁总数10榀,其中二层有7榀预应力梁,屋面层有3榀预应力梁。预应力梁的跨度最大在22 m,梁的最大截面达600mm×1400mm。该工程的预应力钢筋均选择了Ⅱ级松弛 15.24钢绞线,预应力钢绞线抗拉强度标准值为一1860MPa,张拉控制应力=1302MPa,单根预应力钢筋张拉控制应力一182.3kN,锚具均选择了I类锚具,张拉端选择夹片锚具,固定端选择挤压锚具,预应力梁混凝土强度等级都达C45。
2后张有黏结预应力梁的施工工艺
2.1工艺流程
先完成梁模板的安装,但对预应力梁边侧模的安装需要相对延迟,这是为了给穿预应力筋的布置保留空间,扎常规钢筋及穿预应力筋;安装张拉端锚垫板和间接钢筋,对梁边模板密封处理。对于黏结预应力砼施工的处理,则主要是将其融合在常规钢筋砼施工工序里,详细施工操作流程如图1所示。……
