Title:
Fracture Behavior of Three-Dimensional-Printable Cementitious Mortars in Very Early Ages and Hardened States
Author(s):
K. Sriram Kompella, Andrea Marcucci, Francesco Lo Monte, Marinella Levi, and Liberato Ferrara
Publication:
Materials Journal
Volume:
121
Issue:
2
Appears on pages(s):
49-58
Keywords:
flexural strength and work of fracture; influence of layers; shear behavior; testing methods; three dimensional (3-D)-printable cementitious composites; very-early-age tensile constitutive behavior
DOI:
10.14359/51740302
Date:
4/1/2024
Abstract:
The early-age material parameters of three-dimensional
(3-D)-printable concrete defined under the umbrella of printability,
namely, pumpability, extrudability, buildability, and the “printability
window/open time,” are subjective measures. The need to
correlate and successively substitute these subjective measures
with objective and accepted material properties, such as tensile
strength, shear strength, and compressive strength, is paramount.
This study validates new testing methodologies to quantify the
tensile and shear strengths of printable fiber-reinforced concretes
still in their fresh state. A tailored mixture with high sulfoaluminate
cement and nonstructural basalt fibers has been assumed as
a reference. The relation between the previously mentioned parameters and rheological parameters, such as yield strength obtained through International Center for Aggregates Research (ICAR) rheometer tests, is also explored. Furthermore, in an attempt to pave the way and contribute toward a better understanding of the
mechanical properties of 3-D-printed concrete, to be further transferred into design procedures, a comparative study analyzing the work of fracture per unit crack width in three-point bending has
been performed on printed and companion nominally identical
monolithically cast specimens, investigating the effects of printing
directions, position in the printed circuit, and specimen slenderness
(length to depth) ratio.