BFRP约束钢筋混凝土轴压圆柱的尺寸效应研究

Size effect in axially loaded reinforced concrete columns confined by BFRP sheets

为了研究结构的尺寸效应,开展了3种不同尺寸几何相似玄武岩纤维布约束钢筋混凝土圆柱的轴压试验。试验总共设计制作了27个试件,15根为对比未加固试件,12根为约束(加固)试件,并按试件直径将它们分为150、200、250mm 3组。3组试件的箍筋直径、纵筋直径及加固用的BFRP层数分别按3∶4∶5制作。试验结果表明,试件破坏时的名义应力随着试件尺寸的增大而降低,即试件强度具有尺寸效应,且几何相似圆柱强度的尺寸效应遵循Banzant的尺寸效应规律。

In order to study the size effect, the axial compression experiment of three kinds dimension specimens were conducted. 27 specimens were made and tested and 12 of them were confined by BFRP sheets and the others are no-confined ones. The diameters of columns are 150, 200 and 250mm and they were divided in 3 groups by different geometrical dimensions. The diameters of longitudinal reinforcement and stirrups and the number of BFRP layers were designed according to the same ratio of 3 ： 4 ： 5. The experimental results showed that the nominal stress of the specimens descended as the dimension of specimens increase and this showed that the size effect exist in the strength of the specimens. And the size effect of the specimens has good agreement with the Bazant size-effect law.