Banca de DEFESA: OTAVIO WESLEY CAVALCANTI FAUSTINO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : OTAVIO WESLEY CAVALCANTI FAUSTINO
DATE: 11/07/2022
TIME: 09:00
LOCAL: pos graduação engenharia civil on line
TITLE:

Analysis of Hydromechanical Behavior and the Crack Formation Process in Expansive Soil Reinforced with Green Coconut Fibers

KEY WORDS:

Expansive soil. Fiber Reinforcement. Expansion. Crack Test.

PAGES: 131
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The green coconut fiber, the derived compound from the coconut production process, is an environmental liability and can become a waste, since it is traditionally discarded in inappropriate places, polluting beaches and cities, in opposition to local laws. The disposal of this fiber causes an environmental impact, mainly because it occupies urban spaces and sanitary landfills, while burning it leads to the emission of gases. In this research, the feasibility of reusing coconut fibers as reinforcement in expansive soil from Paulista/PE is investigated through laboratory experiments, by using a sample of compacted soil and in its mixtures with coconut fibers in proportions by weight of 0.25%; 0.50%; 1.00%; and 2.00%. The experiments include: granulometry, atterberg's limits, compression, swelling potential, squeeze flow, direct shear, water retention, hydraulic conductivity and analysis of crack formation and propagation by drying. With the addition of coconut fibers, there is a reduction in soil swelling potential from 101.7 kPa, for the natural soil, to 25.8 kPa, for the soil with 1% coconut fiber, a 74.63% reduction, but with 2% coconut fiber, the swelling potential does not decrease, which seems to indicate that there is a limit to the effectiveness of this application. Regarding compression, the best percentage of fiber is 1%, showing an increase in maximum tension of 57.49%. In the direct shear test, the soil and the mixtures assumed a plastic behavior, as the applied stress increased. The hydraulic conductivity does not change significantly with the addition of fiber, in no sample does the value exceed the permeability of (10^-9 m/s). The crack intensity factor (CIF) decreases as the fiber content increases, with the maximum crack reduction being achieved by the use of the 2% coconut fiber sample. The inclusion of coconut fibers also transforms the wide cracks in the natural soil into narrower cracks. The insertion of green coconut fibers into the expansive soil of Paulista improves all the investigated geotechnical characteristics of the expansive soil, therefore, coconut fibers can be used as reinforcement materials in expansive soils, reducing an environmental liability.

BANKING MEMBERS:
Presidente - 1066974 - ANALICE FRANCA LIMA AMORIM
Externo à Instituição - OLAVO FRANCISCO DOS SANTOS JUNIOR - UFRN
Externa à Instituição - STELA FUCALE SUKAR - UPE