大直径高强预应力钢绞线与混凝土粘结锚固性能试验

Experiment of bond-anchorage properties of large-diameter high-strength prestressed steel strand with concrete

为研究大直径、高强预应力钢绞线与混凝土及灌浆料的粘结锚固性能,以相对锚固长度、相对保护层厚度和箍筋间距为参数,对30个拉拔试件、3根钢铰梁试件进行试验研究,获得了拉拔试件、梁式试件的粘结应力-滑移曲线等数据。试验结果表明:各参数相同条件下,梁式试验得到的粘结应力小于拉拔试验得到的粘结应力;随着锚固长度的增加,极限粘结应力有所下降;相对保护层厚度越大极限粘结强度越大;减小箍筋间距能提高钢绞线与混凝土的粘结性能。

In order to investigate the bond-anchorage properties between large-diameter high-strength prestressed steel strand and concrete,the loading tests of 30 pull-out specimens,3 steel hinged beams are carried out with the relative anchorage length,the relative thickness of the protective layer and the stirrup spacing as a parameter,which can obtain the relative slip between concrete and steel strand,then the bond stress-slip curves of pull-out specimens and steel hinged beam are derived. The result show that： the bond stress of steel hinged beams is lower than that of the pull-out specimens; the ultimate bond stress decreases with the increase of the anchoring length;the greater the thickness of the relative protective layer,the greater the bond strength; reducing stirrup spacing can improve the bonding performance between steel strands and concrete.