Banca de DEFESA: HÍTALO JOSÉ TAVARES DE ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : HÍTALO JOSÉ TAVARES DE ARAÚJO
DATE: 24/02/2023
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Engenharia Civil
TITLE:

Influence of the Use of Tire Fibers on Hydromechanical Behavior and Mitigation of Crack Propagation in Expansive Soil

KEY WORDS:

Unsaturated soils; Expansive soils; Tire waste; Cracking; Soil improvement

PAGES: 127
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Expansive soils stand out as some of the most problematic soils due to the great possibility of causing pathologies in constructions due to their nature of volumetric change with the variation of their humidity. The use of soil stabilization techniques to change their unwanted geotechnical characteristics is necessary. The incorporation of tire fiber in the soil has proved to be an interesting option as it makes it possible to reuse tires improperly discarded in nature. The aim, therefore, in this work, is to analyze the mitigation capacity of the volumetric changes and deleterious cracks that can appear in an expansive soil of Paulista-PE with the insertion of tire fibers with mixtures of 0.25%, 0.5%, 1% and 2% in relation to the dry soil weight. The research program included the preparation, physical characterization and investigation of the hydromechanical behavior of natural soil samples and mixtures with tire fibers, verifying changes in soil properties. Comparing with natural soil, all tire fiber contents maintained the same order of magnitude of 10-8 cm/s for hydraulic conductivity. In the squeeze-flow test, at the liquid limit humidity, the yield stress and initial stiffening stress, with the 2% content, obtained the highest values: 7.75 and 3.67 times above. At the plasticity limit humidity, the highest value of the initial stiffening stress occurred with 1%: 2.37 times greater. The “free” expansion had the lowest value in the 2% content samples: a reduction of 23.56%. The expansion stress had the lowest value with a content of 1%: 19.53% lower. The unconfined compressive strength had a higher value with 1%: an increase of 19.46%. For tensile strength, the 2% content had the highest value: 31.32% above. The 2% content obtained the highest shear strengths for all normal stresses. For 200 kPa, it increased by 7.23%. Mixtures with fibers, in general, retained more water than the natural soil for the same suction value. In the drying cracking tests, the 1% sample resulted in a greater reduction in the cracking intensity factor (CIF): 21.16% lower. Therefore, the inclusion of tire fibers promoted improvements in important geotechnical characteristics of the expansive soil, as well as a significant reduction in soil cracking.

COMMITTEE MEMBERS:
Externo à Instituição - JOAQUIM TEODORO ROMAO DE OLIVEIRA - UNICAP
Externa ao Programa - 2984374 - MARIA ISABELA MARQUES DA CUNHA VIEIRA BELLO - nullPresidente - 1654153 - MARIA ODETE HOLANDA MARIANO