Fracture behavior of additively manufactured cementitious materials

Additive manufacturing (AM) of cementitious materials, also known as 3D printing, offers transformative potential for the construction sector.Given the inherently quasi-brittle behavior of cementitious materials and their vulnerability to fracture, it is essential to understand how the layer-by-layer extrusion process affects their fracture resistance.This study explored the interplay between early-age rheology, pore structure, and fracture toughness of additively manufactured cementitious materials.Using three-dimensional micro-computed tomography, the impact of early-age thixotropic behavior and varying printing time intervals on the pore structure of the interlayers was examined.Fracture tests were conducted on printed specimens, incorporating a digital image correlation system for precise monitoring and visualization of crack evolution.The findings demonstrated that fracture toughness of additively manufactured cementitious materials is strongly influenced by their early-age rheological behavior and printing conditions.