Finite Element Modelling of Corrosion-Damaged RC Beams Strengthened Using the UHPC Layers

Area of Science:

• Civil Engineering
• Materials Science
• Structural Engineering

Background:

• Corrosion significantly degrades the flexural strength of reinforced concrete (RC) beams.
• Strengthening RC beams with ultra-high-performance concrete (UHPC) is a promising retrofitting technique.
• Accurate prediction of flexural behavior is crucial for assessing the effectiveness of UHPC strengthening.

Purpose of the Study:

• To develop and validate a finite element model (FEM) for predicting the flexural strength of corrosion-damaged RC beams strengthened with UHPC.
• To investigate the influence of reinforcement corrosion and UHPC layer configurations on beam behavior.
• To conduct a parametric study on the effects of UHPC properties on the flexural performance.

Main Methods:

• Experimental testing of twenty-two corroded, un-strengthened, and UHPC-strengthened RC beam specimens.
• Development of FEMs in ABAQUS, incorporating corrosion-induced degradation of reinforcing bars (diameter and yield strength).
• Simulation of interfacial bond-slip behavior using a cohesive surface bonding approach.

Main Results:

• FEM results for crack patterns, flexural strength, stiffness, and load-deflection behavior closely matched experimental data.
• The validated FEM accurately captures the flexural performance of strengthened RC beams.
• Parametric studies revealed the impact of UHPC compressive strength and thickness on flexural strength.

Conclusions:

• The proposed FEM provides a highly accurate tool for predicting the flexural behavior of corrosion-damaged RC beams strengthened with UHPC.
• The study validates the effectiveness of UHPC as a strengthening material for corroded RC structures.
• The findings support the use of validated FEMs for optimizing the design of UHPC strengthening systems.