预应力纤维布加固混凝土梁冻融特性试验

Experiment on freezing and thawing characteristics of prestressed carbon fiber cloth reinforced concrete beams

为了研究预应力碳纤维布对受冻融作用影响的混凝土梁的加固效果,从而进一步认识混凝土与碳纤维布共同工作的行为,研究了加固梁中碳纤维布和混凝土的各自力学性能以及碳纤维布加固混凝土梁的整体力学性能.结果表明,冻融后的试验梁开裂荷载和极限承载力有所下降;初始预应力水平越高,试验梁的开裂荷载和极限荷载下降速度越快;在冻融循环和预应力耦合作用下混凝土内部损伤严重,碳纤维布-混凝土界面的粘结力退化明显.

In order to clarify the strengthening effect of prestressed carbon fiber cloth on the concrete beams under the freezing and thawing action,and further understand the co-working behavior of concrete and carbon fiber cloth,the respective mechanical properties of carbon fiber cloth and concrete in the reinforced beam as well as the overall mechanical properties of carbon fiber reinforced concrete beams were investigated. The results show that after freezing and thawing,the cracking load and ultimate bearing capacity of test beams decrease. The higher the initial pre-stress level is,the faster the decreasing speed in both cracking load and ultimate load of test beams is. Under the action of freezing and thawing cycle and prestressed coupling,the concrete exhibits serious inside damage,and the deterioration of bonding force between carbon fiber cloth and concrete is obvious.