钢管混凝土局部承压性能和强度计算的研究

Bearing Strength of Concrete-Filled Steel Tubes

本文报道了43个钢管混凝土试件的局部承压试验结果。试验的主要参数为:局压面积比、钢管的径厚比D/t以及试件的相对高度H/D。此外还研究了在钢管混凝土局压区设置螺旋箍筋对局压强度的提高作用。试验结果表明,钢管混凝土的局压强度提高系数高于其它形式的套箍混凝土;附加螺旋筋所提高的局压强度仍可用平方根公式计算。

Concrete-filled steel tube (CFST)is a kind of confined concrete. Like other kinds of confined concrete, a greatly improved bearing strength of CFST can be expected. However, up to now there has been no research on this problem both in China and abroad.This paper gives test results on bearing strength of 43 CFST specimens. The main experimental parameters are the ratio of bearing area to core area, the ratio of diameter to wall-thickness of tube, and the relative height of specimen. The effect of supplement of spiral reinforcement on bearing strength of core concrete are also investigated. The main conclusions are as follows:1. The bearing strength ratio of CFST is higher than that of concrete confined by spirals or nets. But it can still be calculated using the same expression as that of spirals and nets.2. Supplement of spiral reinforcement can further enhance the bearing capacity of CFST, and the bearing capacity of this kind of element can be calculated using the formula of square root.