Workshop: Simulation Flexural Behavior Of Reinforced Concrete Beams Strengthened With Ultra High Performance Concrete In Abaqus

In this tutorial, the flexural behavior of reinforced concrete (RC) beams strengthened with ultra‑high‑performance concrete (UHPC) is simulated in Abaqus. Strengthening concrete structures is important not only for repairing deteriorated members but also for improving the performance of new structural elements under service loads. This need is especially critical in major facilities such as power stations, nuclear plants, and marine structures, where demolition is often not feasible.

UHPC is a modern material widely used for both repair and strengthening of RC structures. In the model, the concrete beam and UHPC layer are created as three‑dimensional solid parts. The reinforcing bars and steel strips are modeled as three‑dimensional wire parts.

The Concrete Damaged Plasticity (CDP) model is applied to the concrete beam. This model represents concrete behavior using a plasticity‑based damage approach and considers two main failure mechanisms: tensile cracking and compressive crushing. The steel bars and strips use an elastic‑plastic material model. The UHPC layer also uses the CDP model, with material parameters taken from the reference study.

A general static step is used, with adjustments to improve convergence. Surface‑to‑surface contact with friction is defined between the concrete beam and the rigid bodies. The bars and strips are embedded within the concrete host. The two bottom rigid bodies are fixed, while the top rigid body is given a displacement with a smooth amplitude curve. A fine mesh is required to obtain accurate results.

After running the simulation, results such as stress, strain, tensile and compressive damage, and displacement can be extracted. Figures of the model and results are shown below.