Early-age buildability-rheological properties relationship in additively manufactured cement paste hollow cylinders

Ability to extrude and achieve shape stability of layer-wise additively manufactured cement-based elements at large scale depends upon the early-age rheological properties (shear moduli, yield stress, viscosity) deposited materials. Upon successful extrusion, buildability challenges can manifest themselves through two common failure mechanisms: yielding lower layers or buckling element. However, it is yet unclear which various control materials' deformation, specifically buckling, during printing processes thus influence resulting elements. This paper focuses on how dependent as well predicting using a theoretical framework. Specifically, relationship between cement pastes hollow cylinders with dominated by mechanism was investigated. It found that certain types shear moduli fresh (G, G*, G′) obtained from oscillatory stress sweep tests, performed within first 30 min hydration, correlate better than some other (loss modulus G″, σ yield, strain γyield, complex viscosity η*). Measured values (G) were used calculate elastic (E) assumed value 0.5 for Poisson's ratio (ν) paste. Euler's theory predict (height element) cylinders. overestimates 93%–194%, mainly due assumption ideal geometry (i.e., absence initial imperfection), rate-independent behavior linear elasticity.