Failure Process of Modeled Recycled Aggregate Concrete under Uniaxial Compression

Area of Science:

• Civil Engineering
• Materials Science
• Computational Mechanics

Background:

• Recycled aggregate concrete (RAC) is a sustainable construction material.
• Understanding the failure mechanisms of RAC is crucial for its wider application.
• Existing models often simplify the complex meso-structure of RAC.

Purpose of the Study:

• To investigate the failure processes of recycled aggregate concrete.
• To establish a micromechanical numerical model for simulating progressive cracking in RAC.
• To validate the model against experimental data.

Main Methods:

• Discrete Element Method (DEM) for micromechanical modeling.
• Calibration of microscopic contact parameters using nanoindentation tests.
• Experimental testing and Digital Image Correlation (DIC) for validation.

Main Results:

• Accurate simulation of stress-strain curves, cracking process, and failure patterns.
• Capture of microcrack initiation, growth, interaction, and coalescence.
• Identification of cracking modes influenced by RAC meso-structures.

Conclusions:

• The DEM model accurately predicts RAC failure behavior.
• The shear strength of interfacial transition zones (ITZs) is a dominant factor in macroscopic mechanical behavior.
• Meso-structural characteristics significantly influence cracking modes in RAC.