予应力新技术試驗报导

• 作 者: 何希聖
• 机 构: 一分局,
• 出 处: 机械工厂设计
• 发表日期: 1957年08期
• 关键词: 应力 上弦 所用 钢筋混凝土 第一 力纲 静算 土境 吹洗 混凝

一般予应力鋼筋混凝土吊車梁比普通鋼筋混凝土吊車梁,所用的鋼材少不了許多。鑒于此种情况,我局專家建議把予应力吊車梁的混凝土分兩个阶段澆灌:鋼筋安放就位并待下弦受力鋼筋施加予应力之后,进行第一阶段的混凝土澆灌,其澆灌高度为400公厘,同时把混凝土表面划毛,待混凝土达到70％的强度时,放松予应力鋼筋。停歇一小时或更多的时間,再进行第二阶段的澆灌,澆灌之前,

Generally, the prestressed reinforced concrete crane girder has much less steel than the ordinary reinforced concrete crane girder. In view of this situation, the experts of the Bureau proposed that the concrete of the prestressed crane girder should be poured into water in two stages: after the steel bar is placed in position and applied to the stress by the lower chord reinforced steel bar, the first stage of concrete watering is performed with a watering height of 400 In millimeters, at the same time, the surface of the concrete is feathered, and when the strength of the concrete reaches 70%, the stress reinforcing steel bar is relaxed. Stop for an hour or more before proceeding to the second stage of watering, before watering,