Mechanical Behavior Degradation and Constitutive Relationship of Fiber Reinforced Concrete Under Reciprocating Compression
To study the mechanical properties and constitutive relationship of steel fiber reinforced concrete under re-ciprocating axial compression loads,this paper conducted uniaxial reciprocating compression tests.Different fiber con-tents and length-diameter ratio were taken as experimental variables to explore the mechanical behavior degradation and damage evolution of steel fiber reinforced concrete.Compared with monotonic loading,the results show that the strength of steel fiber reinforced concrete specimens under reciprocating loading exhibits slight degradation;The accumulation of plastic strain in concrete decreases significantly with the increase of steel fiber volume fraction,and the degradation rate of elastic stiffness increases accordingly,but the effect of fiber length to diameter ratio is not significant;The stress degra-dation rate of concrete shows a trend of first decreasing and then increasing with the unloading strain;A damage evolution model for steel fiber reinforced concrete under reciprocating axial compression was established based on the phenomenon of mechanical behavior degradation and fiber reinforcement effect.Comparison of experimental results show that the mod-el was in good agreement with experimental data.