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预应力屋架(梁)按施工制作方法分为先张法与后张法两种。一般当跨度≥15米时,往往由于运输设备、道路条件及城区路口转弯半径以及生产工艺条件的限制,目前我国多数采用后张法制作。本文着重谈谈后张法预应力屋架(梁)在设计、生产制作过程中经常遇到的几个问题。一、保证混凝土质量问题预应力屋架在施工制作及浇灌混凝土时,对屋架质量要求最关键的部位是屋架的上,下弦及节点。屋架上弦属于小偏心受压杆件。例如,30米跨度的屋架一般采用400号混凝土,当屋面荷载为400公斤/米~2时,甚至采用500号混凝土。上弦的压力
The prestressed roof truss (beam) is divided into two kinds: pretensioning method and post-tensioning method. Generally, when the span is ≥15 meters, most of the current methods in China are post-tensioned due to restrictions on transportation equipment, road conditions, turning radius of urban road junctions, and production process conditions. This article focuses on several issues that are commonly encountered in the design and production of post-tensioned prestressed roof trusses (beams). First, to ensure the quality of concrete Prestressed roof truss In the construction and pouring concrete, the most critical parts of the truss quality requirements are the upper and lower chords and nodes of the truss. The truss winding is a small eccentric compression member. For example, a truss with a span of 30 meters generally uses No. 400 concrete, and when the roof load is 400 kg/m~2, even No. 500 concrete is used. Winding pressure