载荷对预应力混凝土梁残余预应力影响的试验研究

一般预应力损失是计算预应力构件在使用前损失的那部分预应力,对于构件使用时载荷对预应力损失的影响则没有考虑。有研究表明,构件使用过程中的载荷也可能会导致预应力损失或导致残余预应力减小。通过3根预应力混凝土梁的加载试验表明,加载在24 h以内并不导致构件产生钢筋松弛预应力损失,而且还会因为混凝土的徐变使残余预应力微量增加。同时,试验还显示重复加载、卸载对残余预应力几乎没有影响。

Test Study on Load Effect on Residual Prestress of Prestressed Concrete Beam

Prestress loss calculation generally is the one for the part of prestress member loss undergone before using. The calculation of load effect on the prestress loss was not considered. Some studies reveal that the load of member used may lead to prestress loss or reduce of residual prestress. Loading test of three prestressed concrete beam shows that less than 24 hours＇ loading don＇t result in the prestress loss caused by steel slack, but the little increase of residual prestress due to the concrete creep. At the same time ,the test also shows that repeat of loading and unloading almost have no effect on the residual prestress.