预应力混凝土结构钢绞线现存应力测试研究  

RESEARCH ON EXISTING STRESS MEASUREMENT OF STRANDS FOR PRESTRESSED CONCRETE STRUCTURES

作　　者：郭学兵[1,2] 韩之江[1] 刘志华[1,2] 郭文龙[1,2] 刘建勋[1] 

机构地区：[1]山西省交通科学研究院桥梁工程防灾减灾山西省重点实验室,太原030006 [2]山西省交通科学研究院黄土地区公路建设与养护技术交通行业重点实验室,太原030006

出　　处：《工业建筑》2016年第1期80-83,94,共5页Industrial Construction

基　　金：山西省交通运输厅科技项目(2013-1-06)

摘　　要：为求得混凝土结构中钢绞线的现存应力,将传统的适用于钢筋的应力释放法引入钢绞线应力测量,提出了对钢绞线单股钢丝进行应力释放的跨距同股切割法,在此基础上研究了测试截面应力重分布、"零飘"等因素对测试结果的影响。结果表明:测试截面削弱产生的应力重分布对测试结果的影响在2%以内;试验中热输出占比很小,虽然机械扰动应变波动较大,但切割结束后会迅速趋于平稳且绝对值较小;测点与应力释放点距离不小于200 mm时,"零飘"对测试结果的影响在5‰以内。To obtain the existing stress of steel strand in concrete structure,traditional stress release method always applied to rebar stress measurement was introduced into steel strand stress measurement. A specific cutting the same wire over a certain distance method,in which the stress of one stream of steel wire within strand was released to obtain the existing stress of this wire and then deducing the strand stress,was proposed. Meanwhile,the influence of concrete cover removing size on tested cross section stress redistribution and how to control ＂zero drift＂in stress measurement were studied. The analysis results showed that the effect of stress redistribution caused by the weakness of tested cross section on the test results was within 2%. Heat output accounted for a small proportion in the test result,on the contrary,mechanical disturbance accounted for large. Mechanical disturbance strain fluctuated obviously in the process of cutting but quickly changed to stability with small absolute value after cutting. When the distance between measurement point and stress release point was not less than 200 mm,the effect of＂zero drift＂on the rest results would be within 5‰.

关 键 词：预应力混凝土 钢绞线 现存应力 应力测试 应力释放法 

分 类 号：TU378[建筑科学—结构工程]