监理检测网论坛
3c3t - 2007/7/31 9:24:00
预应力筋张拉时发生断丝、滑丝怎么办?@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
1、质量问题及现象@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
预应力筋在张拉与锚固时,由于各种原因,发生预应力筋的断丝和滑丝,使预应力钢束受力不均匀,造成构件不能达到所要求的预应力度。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
2、原因分析@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
1)实际使用的预应力钢丝或预应力钢绞线直径偏大,锚具与夹片不密贴,张拉时易发生断丝或滑丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
2)预应力束没有或未按规定要求梳理编束,使得钢束长短不一或发生交叉,张拉时易发生断丝或滑丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
3)锚夹具的尺寸不准,夹片的误差大,夹片的硬度与预应力盘不配套,易屡丝和滑丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
锚圈放置位置不准,支承垫块倾斜,千斤顶安装不正,会造成预应力钢束断线。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
4)施工焊接时,把接地线接在预应力筋上,造成钢丝间短路,损伤钢丝,张拉时发生断丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
5)把钢束穿入预留孔道内时间长,造成钢丝锈蚀,砼砂浆留在钢束上,又未清理干净,张拉时产生滑丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
6)锚圈放置位置不准,支承垫块倾斜,千斤顶安装不正,会造成预应力钢束断线。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
7)油压表失灵,造成张拉力过大,易产生断丝。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
3、预防措施@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
1)穿束前,预应力钢束必须按规程进行梳理编束,并正确绑扎。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
2)张拉预应力筋时,锚具、千斤顶安装要准确。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
3)张拉预应力筋时,锚具、千斤顶安装要准确。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
4)当预应力张拉达到一定吨位后,如发现油压回落,再加油时又回落,这时有可能发生断丝,如果发生断丝,应更换预应力钢束,重新进行预应力张拉。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
5)焊接时严禁利用预应力筋作为接地线,不允许发生电焊烧伤波纹管与预应力筋。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
6)张拉前必须对张拉端钢束进行清理,如发生锈蚀应重新调换。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
7)张拉前要经权威部门准确检验标定千斤顶和油压表。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
8)发生断丝后可以提高其它束的张拉力进行补偿;更换新束;利用备用孔增加预应力束。@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
Lily0927 - 2007/7/31 10:18:00
感谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
qingzhou - 2007/12/24 11:09:00
分析的好啊@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
qwerok - 2007/12/24 21:40:00
很好哦@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
lidexing - 2008/2/14 9:59:00
感谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
阿洋 - 2008/3/7 8:11:00
谢谢了,非常好小文章@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
libin1 - 2008/3/21 16:53:00
dddddddddddd@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
楠丫 - 2008/5/8 18:38:00
谢谢,实用@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
zhbin1858 - 2008/5/12 17:37:00
谢谢分享!@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
wxliang0523 - 2008/5/17 14:46:00
不错呀@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
谢谢@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
qushaogui - 2008/5/17 20:46:00
感谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
qushaogui - 2008/5/17 20:47:00
感谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
qushaogui - 2008/5/17 20:48:00
感谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
chyzy505 - 2008/8/17 17:35:00
实际使用的预应力钢丝或预应力钢绞线直径偏大,锚具与夹片不密贴,张拉时易发生断丝或滑丝@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
好资料@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
又上了一课,原以为钢绞线 规范是 139 mm2@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
有些取值一般是 140 mm2@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
实际有些达 143 的情况 ,本以为,比设计大就行.@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
没想到还有这么多问题@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
龙 - 2008/8/17 17:49:00
有用处,就是太简单了@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
错错 - 2008/12/31 20:54:00
顶一下:default6:@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
ZFJ - 2009/2/3 23:33:00
谢谢分享@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
王华2009 - 2009/2/7 13:40:00
太好了,感谢楼主的恩赐!@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
lidexing - 2009/9/18 9:10:00
谢谢了@V¿ôÊS(°§ôbbs.3c3t.comCâjx9³`ïá
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