钢管自密实高性能混凝土压弯构件力学性能研究

Research on behavior of self consolidation concrete filled steel tubular beam columns

进行了38个钢管自密实高性能混凝土压弯构件的试验研究,考察的项目和基本参数有:(1)截面形式,包括22个圆试件和16个方试件;(2)管内混凝土不同浇筑方式,包括自密实、手工振捣和机械振捣;(3)截面径(宽)厚比,从33变化到67;(4)荷载偏心率,从0变化到0.3。研究目的在于:考察钢管自密实混凝土与采用振捣密实的钢管混凝土压弯构件力学性能的差异,并比较规程DL/T5085—1999、GJB4142—2000、AIJ(1997)、EC4(1994)、AISC—LRFD(1999)、BS5400(1979)和DBJ13—51—2003在计算钢管自密实高性能混凝土构件极限承载力时的差异,结果是圆钢管自密实混凝土压弯构件的极限承载能力值按规范计算比试验值低5%～20%,方钢管按规范计算比试验值低4%～15%,唯按EC4(1994)计算的方钢管值略高于试验值。

Thirty eight self consolidation concrete filled steel tubular beam columns subjected to axial compression and compression bending were carried out including 18 stub columns and 20 beam columns. The main parameters varied in the tests were: (1) column section types, circular and square;(2) pouring methods, compacted with a poker vibrator, well compacted by hand, and self consolidation without any vibration; (3) tube diameter (or depth) to thickness ratios, from 33 to 67; (4) load eccentricity ratios (e/r), from 0 to 0.3. An attempt was made to know the differences of results by different design codes including DL/T5085—1999,GJB4142—2000,AIJ(1997),EC4(1994),AISC—LRFD(1999),BS5400(1979)and DBJ13—51—2003.The research showed that self consolidation concrete filled steel tubes have good bearing capacity and ductility. The results of all the codes are in good agreement with those of the test, and all results obtained from codes were somewhat conservative except EC4(1994)for square tubes. They are suitable to be adopted to design and calculate bearing capacity of self consolidation concrete filled steel tubes beam columns.