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Multiaxis three-dimensional (3D) continuous polymeric carbon fiber/cementitious concretes were introduced. Their angular (off-axis) flexural properties were experimentally studied. It was found that the placement of the continuous carbon fibers and their in-plane angular orientations in the pristine concrete noticeably influenced the angular flexural strength and the energy absorption behavior of the multiaxis 3D concrete composite. The off-axis flexural strength of the uniaxial (C-1D-(0°)), biaxial (C-2D-(0°), and C-2D-(90°)), and multiaxial (C-4D-(0°), C-4D-(+45°) and C-4D-(−45°)) concrete composites were outstandingly higher (from 36.84 to 272.43%) than the neat concrete. Their energy absorption capacities were superior compared to the neat concrete. Fractured four directional polymeric carbon fiber/cementitious matrix concretes limited brittle matrix failure and a broom-like fracture phenomenon on the filament bundles, filament-matrix debonding and splitting, and minor filament entanglement. Multiaxis 3D polymeric carbon fiber concrete, especially the C-4D structure, controlled the crack phenomena and was considered a damage-tolerant material compared to the neat concrete. [ABSTRACT FROM AUTHOR]

Multiaxis three-dimensional (3D) continuous basalt fiber/cementitious concretes were manufactured. The novelty of the study was that the non-interlace preform structures were multiaxially created by placing all continious filamentary bundles in the in-plane direction of the preform via developed flat winding-molding method to improve the fracture toughness of the concrete composite. Principle and off-axis flexural properties of multiaxis three-dimensional (3D) continuous basalt fiber/cementitious concretes were experimentally studied. It was identified that the principle and off-axis flexural load-bearing, flexural strength and the toughness properties of the multiaxis 3D basalt concrete were extraordinarily affected by the continuous basalt filament bundle orientations and placement in the pristine concrete. The principle and off-axis flexural strength and energy absorption performance of the uniaxial (B-1D-(0°)), biaxial ((B-2D-(0°), B-2D-(90°) and B-2D-(+45°)), and multiaxial (B-4D-(0°), B-4D-(+45°) and B-4D-(−45°)) concrete composites were considerably greater compared to those of pristine concrete. Fractured four directional basalt concretes had regional breakages of the brittle cementitious matrix and broom-like damage features on the filaments, fiber-matrix debonding, intrafilament bundle splitting, and minor filament entanglement. Multiaxis 3D basalt concrete, particularly in the B-4D structure, controlled the crack phenomena and it was recognized as a more damage-tolerant material than the neat concrete. [ABSTRACT FROM AUTHOR]

Multiaxis three-dimensional (3D) alkali-resistant continuous glass fiber/cementitious matrix concrete composites were developed using the "winding and molding" method. The panel properties of the concretes were experimentally investigated and compared with the neat concrete. The experiment revealed that the load-bearing capability, strength and energy absorption properties of the multiaxis three-dimensional concretes were significantly influenced by the placement and orientation of the reinforcement fiber. The newly developed concrete composite was found to have the strain hardening behavior which attributed to an improved energy absorption performance of the concrete. It was also identified that four directional glass structure (ARG-4D) demonstrated somewhat better energy absorption performance compared to that of the biaxial (ARG-2D) and uniaxial (ARG-1D) structures because of the fiber orientation in the multiaxial direction in the concrete. Further investigation of the fractured four directional glass fiber/cementitious matrix concrete (ARG-4D) showed that the fiber-matrix interfacial debonding in each yarn set, local matrix breakages, yarn bridging due to tensile strengthening, tensile pull-out of outer filament and stick-slip frictions between the filament TOWs and the cementitious matrix were the principal fracture mechanisms. The micro-cracks occurred in multiaxis concretes were restricted by the multiaxis 3D fiber architecture. The multiaxis three-dimensional alkali-resistant continuous glass fiber/cementitious concrete can be considered as the damage tolerant structures with regard to neat concrete. • The multiaxis 3D AR-Glass fiber/cementitious matrix concretes were developed. • Load-displacement had four distinct stages as elastic, initial crack, strain hardening and failure stages. • The fiber architecture including orientation extraordinarily influenced the strength properties of the neat concrete. • Multiaxis AR-Glass concretes showed better energy absorption capacity compared to the neat concrete. • The multiaxis 3D AR-Glass fiber concretes exhibited damage tolerant behavior compared to the neat concrete. [ABSTRACT FROM AUTHOR]

• Multiaxis 3D basalt and carbon fiber/cementitious matrix concretes were developed. • Load-displacement had four stages as elastic, initial crack, strain hardening and failure. • Structural fiber architecture and orientation influenced the concrete strength properties. • Multiaxis 3D concrete exhibited better energy absorption compared to the pristine. • Multiaxis 3D concrete displayed damage tolerance behavior compared to the pristine. Multiaxis three-dimensional (3D) continuous basalt and carbon fiber/cementitious matrix concretes were developed and their panel properties were experimentally investigated. It was found that the fiber placement and orientation in concrete remarkably affected its load carrying, strength, and energy absorption performance. It was identified that the multiaxis 3D fiber concrete had strain hardening behavior. The strain hardening increased the energy absorbing capacity of the concrete. Four directional basalt and carbon structures exhibited slightly better energy absorption compared to the biaxial and uniaxial structures due to the multiaxis fiber orientation. Failed fiber concretes had local matrix breakages, matrix-filament bundle debonding in each yarn set, yarn bridging due to tensile strengthening, outer filament tensile pull-out and stick–slip phenomena between filaments in the yarn, and a cementitious matrix. This led to the in-plane angularly radial aligned multiaxis micro cracks, which were probably controlled by the multiaxis 3D fiber architecture, and they were considered damage tolerant materials. [ABSTRACT FROM AUTHOR]