缓凝预应力筋包覆试验  

Coating Experiment for Bond-retarded Prestressed Strand

作　　者：张建辉[1] 薛德胜[2] 周又和[3] 

机构地区：[1]杭州电子科技大学机械工程学院,杭州310018 [2]兰州大学物理科学与技术学院,兰州730000 [3]兰州大学土木工程与力学学院,兰州730000

出　　处：《机械工程学报》2008年第1期212-216,共5页Journal of Mechanical Engineering

基　　金：铁道部科技发展计划(96G56);甘肃省科技攻关计划(GS003-A52-019)资助项目。

摘　　要：在预应力钢筋上连续包裹一层缓凝砂浆是新型缓粘结预应力混凝土体系得以工程应用的关键。利用螺旋输送挤出、模具成型原理,开发出缓凝预应力筋包覆装置,并进行缓凝预应力筋包覆试验。基于流变学理论,分析缓凝砂浆连续包覆过程。理论和试验结果表明:要成功实现自动连续一次完成在预应力钢绞线上均匀密实包裹缓凝砂浆同时包覆塑料(密封砂浆),宾汉姆体的缓凝砂浆在螺旋输送槽和钢绞线与塑料护套形成的环形通道内必须完全处于一种流动状态,而保持流态的条件则是螺旋转数和包覆速度均满足临界值要求。Successive coating a lay of postponed-set mortar （PSM） on prestressed strand is a key to engineering application for a new type of bond-retarded prestressed concrete system. According to the principle of screw conveying and die forming, coating equipment for bond-retarded prestressed strand is developed and coating experiments are carried out. Based on the theories of rheology, successive coating process of PSM is analyzed. The theoretical analysis and the experimental results show the followings. In order to achieve automatically and successively coating PSM and plastic （sealing PSM） on prestressed strand only once, both PSM with Bingham plastic in screw channel and annular passage surrounding strand and polyethylene sheath must be in fully flow state, which means screw revolutions and coating velocity exist respective critical values.

关 键 词：预应力钢筋 缓凝砂浆 连续包覆 

分 类 号：TU646[建筑科学—建筑技术科学] TU311