Banca de DEFESA: ALINE CATIA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ALINE CATIA DA SILVA
DATE: 25/03/2024
TIME: 09:00
LOCAL: Pós-Graduação Engenharia Civil
TITLE:

Hydromechanical, Tensile, Desiccation Cracking Behavior and Application of Fracture Mechanics in an Expansive Soil Reinforced with Short PET Fibers

KEY WORDS:

Expansive clay. Fibers. PET. Cracks. Direct tensile. Fracture mechanics.

PAGES: 193
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The soils are the essential support raw material for Civil Construction, however they can present problematic characteristics when subject to moinsture variations, such as expansive clays that expand or contract. On the other hand, growing industrialization results in increased waste production, especially plastics such as Polyethylene Terephthalate (PET), which are often disposed of inadequately. The use of PET materials by recycling programs is limited, and it is an option to incorporate them into Civil Construction through soil reinforcement. The present study investigates the hydromechanical, traction and cracking behavior of an expansive soil compacted and mixed with fibers from the manufacture of PET, in the percentages of 0,25%, 0,5%, 0,75%, 1% and 2% dry weight and lengths of 12 mm. In addition, we seek to apply the concepts of fracture mechanics and understand the effect reinforcement PET fibers on expansive soil. The higher contents of PET fibers incorporated into the soil reduce the maximum dry specific weight and optimum moinsture, cause increases in “free” expansion and reduce the expansion stress. The yield stresses and stiffening stresses soil in the squeeze-flow tests and the resistances to simple compression and diametrical compression are increased by the incorporation of PET fibers, however these have little effect on the hydraulic conductivity of the soil. The process of formation and propagation of cracks in drying the expansive soil was analyzed, and a reduction in the development of cracks was obtained as the fiber content increased. Equipment was designed, adapted and built in the laboratory to evaluate direct traction and fracture toughness. In direct tensile tests, the PET fibers prolong the time to failure, develop residual tensile stresses after failure, and increase the direct tensile strength of the soil. The method used in fracture toughness tests allows estimating fracture mechanics parameters on the soil and the fracture load increases with the reduction of the initial length of already existing cracks from 30 mm to 15 mm. The PET fibers increase the fracture load capacity of the expansive soil, confirming the good soil-fiber interaction and the benefits of reinforcement.

COMMITTEE MEMBERS:
Externo à Instituição - JOAQUIM TEODORO ROMAO DE OLIVEIRA - UNICAP
Presidente - 1413233 - LEONARDO JOSE DO NASCIMENTO GUIMARAES
Externa à Instituição - MICHELE DAL TOE CASAGRANDE - UnB
Externo à Instituição - SANDRO LEMOS MACHADO - UFBA
Externa à Instituição - STELA FUCALE SUKAR - UPE