摘要
在 3种约束比下FRP约束混凝土圆柱体试件准静载和快速加载试验的基础上 ,进行多次打击试验及多次打击后的准静载试验。结果表明 :FRP约束混凝土是一种抗多次打击能力较好的抗压复合材料 ,经每次打击后的刚度虽逐渐衰减 ,但有收敛趋势 ,其残余刚度随约束比 ξ及最大应力比 η的增加而减小。经受多次打击后的FRP约束混凝土与未经受多次打击的试件相比 ,其准静载下的初始弹性模量降低 ,强度基本不变 ,极限应变提高 ,其中弱约束混凝土延性提高得尤其显著 ,强约束混凝土应力 应变曲线中线性强化段的斜率随刚度衰减程度的增加而增加 ,最终FRP强约束混凝土有变成线弹性材料的趋势 。
Based on the quasi-static and rapid loading test results of short cylindrical concrete specimens wrapped with fiber reinforced plastic (FRP) under three different constraint ratios (ξ), the multi-hitting test and quasi-static loading test after multi-hitting were conducted. The test results show that FRP confined concrete is a kind of material which can well resist multi-hitting. The stiffness of FRP confined concrete decreases along with increasing hitting times and also gradually converges. The final residual stiffness decreases along with ξ and η (ratio between maximum hitting stress and strength of FRP confined concrete) increase. For FRP confined concrete damaged by multi-hitting, compared with intact specimens, the elastic modulus decreases, while the strength is nearly unchanged and the ultimate strain increases. Ductility of FRP weak-confined concrete damaged by multi hitting obviously increases. The slope of linear strengthening of the stress-strain curve of FRP well-confined concrete damaged by multi-hitting increases along with the damage degree increasing and the final stress-strain curve of FRP well-confined concrete gradually approaches to linear elastic. This work provides the basis for further research on application of FRP confined concrete to defending structures.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2004年第5期128-133,共6页
Acta Materiae Compositae Sinica
关键词
FRP
约束混凝土
约束比
多次打击
Concrete testing
Failure (mechanical)
Loading
Stiffness
Stress analysis
Test facilities
