Unraveling meso-structural evolution in fiber-reinforced concrete with recycled powder: evidence and insights from X-ray computed tomography (CT) and fractal theory

This study investigates the damage behavior of fiber-reinforced concrete incorporating recycled concrete powder (RCP) using X-ray computed tomography (CT) and fractal theory. High-resolution 3D CT imaging was used to quantify internal damages, while fractal theory analyzed damage evolution. Results show that adding 20% RCP and fibers increased the concrete’s fractal dimension by 10%, highlighting a notable effect on its damage behavior. A strong correlation between fractal dimensions and crack development suggests that fractal analysis can effectively model damage progression. Based on these findings, a novel damage-strain model is proposed, offering a more accurate assessment of concrete damage under loading. This model can be applied to optimize concrete mix designs and improve damage prediction in structural engineering.