Banca de DEFESA: ISABELA DOMINGUES COELHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ISABELA DOMINGUES COELHO
DATE: 29/10/2021
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/peter-ludvig
TITLE:

Study on the piezoresistive properties of composites prepared with pre-dispersed carbon nanotubes on cement particles

KEY WORDS:

Carbon nanotubes; piezoresistivity; smart materials

PAGES: 120
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The need to demolish or repair structures is a recurrent situation in civil construction. Therefore, the importance of an accessible and efficient method of structural monitoring to avoid economic, environmental and human losses is needed.Piezoresistive materials, such as carbon nanotubes (NTCs), can vary their electrical resistance under mechanical deformation, enabling instantaneous structural monitoring, which leads to premature detection of possible failures. Thus, in this present work, cement pastes and mortars were made with the addition of CNTs pre-dispersed in isopropanol. To achieve the best conditions for the piezoresponse essay, the drying method of the composites, the type of electrode, the electrical frequency, the mechanical load applied, and the water saturation level of the samples (100%, 50%, or 25% moisture) went through tests.Mechanical tests were performed (compressive strength and modulus), as well as bulk density and an electrical test (electrical resistance measurements) for parameter analysis and characterization of the composite.Finally, piezoresponse tests were carried out and revealed that composites with 50% water content presented the best piezoresistive behavior, with the mortar being the composite with the highest sensitivity and best piezoresponse reversibility.The possibility of detecting the continuous opening of cracks through the variation of electrical measurements (voltage and electrical resistance) is noted. The mechanical properties were not improved, and the bulk density did not significantly change with the addition of CNTs in the composites.

BANKING MEMBERS:
Presidente - PETER LUDVIG
Interno - ROGERIO CABRAL DE AZEVEDO
Externo à Instituição - JOSÉ MÁRCIO FONSECA CALIXTO - UFMG