Numerical Method for Creep Analysis of Strengthened Fatigue-Damaged Concrete Beams

Abstract

Fatigue-damaged concrete improves the load-bearing capacity of components by increasing the cross section. However, the creep performance of damaged components after the repair has received less attention. Thus, this study establishes a constitutive creep model of strengthened fatigue-damaged concrete on the basis of damage mechanics and numerically simulates the strengthened component. The accuracy of the proposed model is verified by conducting creep tests on fatigue-damaged concrete beams. According to the numerical simulation results, increasing the section height profoundly affects the ability to control their creep deflection. The incremental creep deflection of the beams with a strengthened section height of 50, 100, and 150 mm loaded for 365 days decreased by 0.107, 0.228, and 0.326 mm, respectively, compared with the unstrengthened damaged beam. Moreover, this reinforcement method excellently controls the deflection of the damaged components under a negative bending moment. The model can forecast the creep deformation of undamaged components or damaged components after being strengthened, which facilitates structural maintenance and decision-making about reinforcement.