In recent years , during the detection of the established reinforced concrete or the prestressed concrete box girder bridges etc . the large structures , we can find that the concrete in particular structural positions such as the anchorage zones of prestressed reinforcement with dense reinforcement , the prestressed pipe in which the space of reinforcement or the thickness of concrete cover is small , the top and bottom flange of box girder and so on has brought great difficulty to concrete construction because of the small size and densely - packed reinforcement 对于变截面t梁、工字梁、箱梁等常见结构,截面形式复杂,一些部位尺寸较小且密集配筋,如梁顶板,梁底板,预应力管道间,混凝土不可避免的造成不密实导致耐久性降低,而这些问题往往为设计者所忽略。对于新建桥梁混凝土的密实度问题,尤其是新建桥梁关键部位的混凝土密实度和耐久性问题,人们研究和关心的较少,这也为桥梁的质量监督控制和使用寿命埋下了隐患。
Over the years , obsorbing the advanced technology , the association has developed the straight line drawing machines , wet drawing machines , upside down style wire drawing machines , spool take - up , pay - off unit , wheel heat treating winder , heat treatment take - up , pay - off unit , strander machines , pre - treatment line machines 多年来，吸收先进的专业技术，已研制开发了具有国内领先水平的直进式拉丝机，水箱拉丝机，倒立式拉丝机，收放线机组，工字轮热处理收线机，热处理收放线机组，预处理作业线，管式股绳机和成绳机。
