基于声发射技术的FRP约束混凝土圆柱抗压试验

Compression test of FRP-confined concrete columns based on acoustic emission technique

为研究纤维增强复合材料(FRP)约束混凝土圆柱的损伤机理,进行4组FRP约束混凝土圆柱和2组无约束混凝土圆柱共18个试件的轴压试验,借助声发射技术探测试件加载全过程的损伤信号.结果表明:无约束混凝土试件破坏属于脆性破坏,而受约束混凝土试件破坏属于延性破坏.根据FRP约束混凝土圆柱的受力特点和破坏过程将其分为主动承载阶段和被动承载阶段.在此基础上,提出计算该类构件极限强度的修正公式.该公式物理意义明确,而且具有较高的计算精度.

To explore the damage mechanism of fiber reinforced plastics（FRP）-confined concrete columns,uniaxial compression experiments were carried out on 18 specimens including 4 groups of FRP-confined concrete columns and 2 groups of unconfined,and the damage signals was detected by applying acoustic emission technique.Results indicate that the failure of the unconfined columns is brittle,but the confined ones are ductile.The loading processes of the latter can be divided into active bearing stage and passive bearing stage according to stress characteristics and failure process of FRP-confined concrete columns.Based on the experimental data,a modified formula for the ultimate strength of the FRP-confined concrete columns is presented,which is testified to be reasonable with more accurate results.