Effect of Interfacial Failure on Stress-Strain Behavior of 3D-Printed Mortar Laminates

Abstract

Failure mechanisms of 3D-printed laminates reinforced with fibers are investigated. In order to clarify the effects of layered anisotropy in mortar filaments, compressive tests are conducted using specimens with end constraint under various loading rates. The specimens are cored-drilled in three directions from a laminated body fabricated by 3D printed, as well as those cast in a formwork. By reducing end-constraints, tensile stress is induced at the layer interfaces, and thus the interfacial fracture process is observed by using the Digital Image Correlation (DIC) method. In the coredrilled specimens, it was observed that the stresses drop sharply before reaching the maximum stress, followed by a subsequent recovery in loadbearing capacity. DIC confirmed that cracking initiated at the interfaces. These results were different from the specimens cast in the formwork. It is found that the interfacial failure of laminated mortar depends on the adhesion strength between the filaments. Thus, two-stage failure process is elucidated as an initial brittle fracture along a weak layer interface, followed by a tenacious post-peak response.