Banca de DEFESA: RUAN CARLOS GOULART REZENDE

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RUAN CARLOS GOULART REZENDE
DATA : 06/11/2026
HORA: 09:00
LOCAL: https://meet.google.com/tpg-rvet-iuj
TÍTULO:

OTIMIZAÇÃO DE INTERFACES E MICROCARACTERIZAÇÃO EM MATRIZES CIMENTÍCIAS COM FIBRAS HÍBRIDAS

PALAVRAS-CHAVES:

HFRC, FRC, PVA, Polypropylene, GFRP, Ductility, Toughness, Axial

Compression, CMOD, Cementitious Composites, Interfacial Microcharacterization.

PÁGINAS: 131
RESUMO:

In Civil Engineering, research seeks to mitigate the brittleness of cementitious matrices using
fiber-reinforced composites. Although glass fiber-reinforced polymer (GFRP) bars offer
corrosion resistance, their linear-elastic behavior and low elastic modulus constrain
performance at Serviceability Limit States (SLS), requiring early-warning collapse
mechanisms. This investigation evaluates Hybrid Fiber-Reinforced Concrete (HFRC) to
optimize cracked matrices through tension-stiffening and multiscale fiber bridging, partially
compensating for the high deformability of GFRP at the structural scale. Two
complementary experimental stages were articulated. At the structural scale, poly(vinyl
alcohol) (PVA) and polypropylene (PP) hybridization was studied in GFRP-reinforced
beams under flexure, alongside fresh-state workability impacts that required mechanical
vibration compaction. At the material scale, post-cracking residual flexural tensile strength
was evaluated in notched prisms under crack mouth opening displacement (CMOD) control,
evaluating the impact of geometric variation (micro vs. macro) and hybridization of PP
fibers. In GFRP-reinforced beams, peak load capacity remained equivalent (~83 kN),
whereas the failure mode evolved from brittle crushing to a gradual, controlled collapse with
multiple distributed cracking. In notched prisms, combining PVA with structural PP
macrofibers promoted strain-hardening behavior, reaching a residual strength fR,3 of 3.55
MPa (+143% compared to the system containing only microfibers) and meeting normative
criteria for structural use, whereas Micro-PP mixtures failed serviceability limits.
Microcharacterization confirmed that chemical-physical PVA bonding delays initial
microcracking via fibrillation, while PP macrofibers dissipate energy through frictional pullout. It is concluded that the multiscale mechanism operates consistently to enhance postcracking toughness and control macrostructural damage across regional matrices.

MEMBROS DA BANCA:
Interno - 2035125 - PAULO CESAR GONCALVES
Interna - 1810200 - VALQUIRIA CLARET DOS SANTOS
Externa ao Programa - 1714699 - MIRIAN DE LOURDES NORONHA MOTTA MELO - UNIFEIExterno à Instituição - DAVID HERNÁNDEZ FIGUEIRIDO - UJI