预制小型槽板楼面结构加固设计

Design of strengthening structure of small precast trough slab floor

大型预制槽板自重轻承载力高,主要用于单层工业厂房屋面结构;小型槽板有时用作既有建筑的楼面板,其截面较薄配筋少,钢筋易于锈蚀,楼板承载力退化较普通楼板早,维护和加固的周期较短。小型槽板多肋和板厚较薄的外形特点决定小型槽板加固不仅要提高其承载力,而且要满足构件耐久性和耐火极限时间要求。外粘贴钢加固法能提高承载能力但难以满足防火要求;叠合加固法施工困难,大面积施工进度慢,楼面置换法可以同时解决多方面的问题。

The large precast trough slabs have light weight and high bearing capacity are mainly used in the roof structure of single-story industrial plants.Small trough slabs are sometimes used as floor slabs in existing buildings.The cross-section is thinner and the reinforcement is less likely to be corroded.The load-bearing capacity of the floor slab degrades earlier than that of ordinary floor slabs.The period of the maintenance and reinforcement is shorter.The shape characteristics of multi-ribs and thinner plate thickness of small trough plate determine that the reinforcement of small trough plate not only improves its bearing capacity but also meets the requirements of durability and fire resistance limit time of components.External bonded steel reinforcement method can improve the bearing capacity,the construction of superimposed reinforcement method is difficult,which results in slow construction progress in large area,but floor replacement can solve many problems at the same time.