Fiber Orientation Effects on the Fracture and Flexural Toughness of Extruded Fiber Reinforced Concrete for Additive Manufacturing

In this study, the mechanical properties of a fiber-reinforced cementitious composite (FRCC) were derived for specimens fabricated using two different methods of casting: conventional cast construction and pump-driven extrusion. Through the extrusion process, fibers are more likely to be oriented along the length of the member being cast and will therefore be more efficient since they are aligned parallel to the tensile stresses produced in flexure testing. The FRCC employed 0.5% and 1% polyvinyl alcohol (PVA) fiber reinforcement by volume. The flexural properties of FRCC were determined using four-point bend tests according to a modified ASTM C1609. Calculations included the modulus of rupture (MOR) and flexural toughness based on load-deflection curves. The fracture properties of FRCC were determined by using three-point bend tests on the same design but having notched beams using the two-parameter fracture model (TPFM). Calculations included the Mode I critical stress intensity factor (KIC), the critical crack tip opening displacement (CTODc), the strain energy release rate (GIC), and the total fracture energy (GF). The results show that enhanced ductility and post-peak behavior are achieved in concrete to which fibers have been added, as has been demonstrated in other studies, although this study further demonstrated how preferential fiber alignment produced via an extrusion can enhance fracture and flexural properties of cementitious composites.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil and Environmental Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Jeon, Byeonguk

Chair dc:contributor.committeechair

• Brand, Alexander S.

Committee members dc:contributor.committeemember

• King, Jonathan Lee
• Roberts-Wollmann, Carin L.

• Fiber Reinforced Cementitious Composites
• Concrete 3D Printing
• Additive Manufacturing
• Synthetic Fiber Alignment
• Strain Hardening
• Fracture Strength
• Flexural Strength
• Flexural Toughness

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:38249

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/116074