FRP约束混凝土极限状态下破坏机理分析

FRP通过限制混凝土的侧向膨胀变形,可以有效地提高混凝土的强度和变形能力。试验研究表明被约束混凝土在极限状态随着外包FRP的断裂,内部已破损严重,出现较多碎块且可能存在滑动面。本文针对被约束混凝土极限状态下的破损,基于Mohr-Coulomb破坏条件,结合相关FRP约束圆柱体的试验研究结果的拟合分析,得到峰值强度计算模型,该模型与已有相关计算模型近似保持一致,证明了可以用Mohr-Coulomb原理解释FRP约束混凝土的破坏机理和建立其强度计算模型。该极限平衡下的破坏机理可以解释被约束混凝土在极限状态时侧向膨胀系数的可确定性。

Analysis on Failure Mechanism of FRP-confined Concrete Under Ultimate State

The strength and ductility of FRP-confined concrete can be effectively improved because of concrete lateral dilation is restricted.Experimental results show the core concrete is disintegrated and a sliding plane is formed under ultimate state after external FRP rupture.Based on Mohr-Coulomb failure condition,this paper analyzes the crushed concrete through data regression according to many experimental results about cylinder confined by FRP.A new model for peak strength of confined concrete is presented,which is agreement with existing calculating model.Mohr-Coulomb theory can be used to explain destroy mechanism of FRP-confined concrete and establish its strength model.This destroy mechanism explains the fact that lateral expansion coefficient can be certain under ultimate state.