Based on the characteristics of whole stress-strain curve of concrete undergoing different freeze-thaw cycle

the change rule of damage variable was studied and the damage evolution equation of concrete after freeze-thaw was established.Simultaneously

the influence of the damage threshold on the concrete damage constitutive model under freeze-thaw was explored.Statistical methods was combined with micromechanics.The damage evolution law of the concrete materials subjected to uniaxial compressive stress was simulated by the parallel bar model.Based on the traditional Weibull distribution function of two parameters

the damage threshold paramcter was introduced and the freeze-thaw damage constitutive model of concrete considering effect of plastic strain was proposed.This model can reflect the mechanical characteristics of concrete under low stress or small deformation.Finally

the expression of parameters of Weibull distribution was determined by the uniaxial compression test of concrete material under freeze-thaw condition

and the result of fitting model was contrasted with uniaxial compression test results.It is shown that this model may correctly reflect the stress-strain relation under uniaxial compression.