Mesoscale failure mechanisms and strength prediction of 3D ‐printed concrete ribbed walls

Abstract

This study investigates the mechanical behavior, failure mechanisms, and strength prediction of 3D‐printed concrete ribbed walls under compression, shear, and combined compression–shear loading. Four wall specimens with different internal rib configurations were tested under axial compression, while digital image correlation and x‐ray CT‐informed three‐dimensional mesoscale modeling were used to examine deformation, crack propagation, pore effects, and fiber stress evolution. The experimental results showed that rib configuration significantly affected stiffness, cracking resistance, bearing capacity, and deformation capacity. The diagonal‐rib wall exhibited the highest initial stiffness of 101.76 kN/mm and cracking load of 284.93 kN, whereas the combined‐rib wall reached the highest ultimate load of 492.64 kN but showed greater brittleness. Another combined‐rib configuration achieved the largest ultimate displacement of 10.92 mm, indicating better deformation capacity. Cracks generally initiated near the upper corners and regions without effective rib restraint, and subsequently propagated vertically through the walls. The mesoscale model reproduced the global load–displacement response and general failure pattern, with the simulated peak loads differing from the experimental results by approximately 3%. Empirical equations incorporating void ratio and axial compression ratio were proposed for strength estimation. The mean errors of the compressive, shear, and compression–shear strength equations were approximately 7.5%, 22.65%, and 20.2%, respectively. These equations can capture the observed strength variation trends within the investigated parameter ranges but should be regarded as preliminary empirical relationships rather than general design equations.