PSI - Issue 64

Francisco Játiva et al. / Procedia Structural Integrity 64 (2024) 1468–1475 Jativa et al./ Structural Integrity Procedia

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3.3. Flexural Performance of Fiber-Reinforced Concrete In total, 15 concrete prisms were tested in a displacement-controlled manner using third-point loading to determine the splitting tensile strength, post-peak behavior, deformation energy, and toughness of specimens. Fig. 3 shows the load-displacement diagram for control and recycled aggregate series with polypropylene, abaca, and coconut fibers. The first observation is that all mixes show post-peak behavior to a certain extent, with the one prism of control aggregates and coconut fibers not being able to reach a displacement of 3.5 mm. The second observation is that the peak load in the mixes with recycled aggregates is about 70% on average of the peak load in the mixes with control aggregates. The third observation is that while the post-peak force in all mixes with polypropylene fibers remains roughly constant, we can observe a gradual decrease in the mixes with abaca fibers. The post-peak strength of the mixes with coconut fibers is markedly lower than the post-peak strength of the mixes with polypropylene fibers. Thus, the toughness of the mixes with abaca fibers is on average 48% of the toughness of the mixes with polypropylene fibers, and the toughness of the mixes with coconut fibers is on average 30% of the control.

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Fig. 2. (a) Compressive strength results and (b) dynamic modulus results for control (C) and recycled aggregates (R) with polypropylene fiber (PPF), abaca and coconut fiber.

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Fig. 3. Splitting tensile results for:(a) Control aggregate + polypropylene fibers; (b) Recycled aggregates + polypropylene fibers; (c) Control aggregate + abaca fibers; (d) Recycled aggregates + abaca fibers; (e).Control aggregate + coconut fibers; (f) Recycled aggregates + coconut fibers