Micromechanical Analysis of Steel Fiber Corrosion in Ultra-high Performance Concrete

In order to study the influence of the volume content and corrosion degree of the steel fiber on the strength and deformation of the structure, the large-volume randomization of the steel fiber in ultra-high performance concrete (UHPC) matrix was realized by the ABAQUS software redeveloped by self-compiling Python script file. Based on this, the UHPC defect corrosion simulation method was developed and the equivalent method of the steel fiber corrosion was explored. Finally, the UHPC beam four-point bending test was taked as an example to verify the UHPC micromechanics analysis method, corrosion simulation method, and equivalent means. The results show that when the fiber volume content is 2%, the UHPC beam has the best bending resistance; corrosion weakens the cross-section of fibers, stress concentration near the corrosion pits and the destroyed interfacial bonding are the key factors affecting the corrosion effect. The random material property distribution method is limited to simulate the macroscopic deformation of UHPC beams, and can’t accurately simulate the distribution of stress field.