Banca de DEFESA: FABIA KAMILLY GOMES DE ANDRADE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FABIA KAMILLY GOMES DE ANDRADE
DATE: 21/12/2022
TIME: 09:00
LOCAL: Pós-Graduação em Engenharia Civil
TITLE:

Influence of the Nanotechnology and Lightweight Aggregates in Cementitious Mortars: An Experimental Analysis of the Physical, Mechanical and Acoustic Properties

KEY WORDS:

Lightweight mortars. Nanotechnology. Acoustic absorption. Mechanical strength. Nanosilica

PAGES: 151
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The use of lightweight aggregates in cementitious composites has been the subject of experimental studies, which aim to know their performance, as well as to optimize the physical, mechanical and acoustic properties. Many researchers said that these lightweight aggregates have got an influence on sound absorption, due to their lightness, but it can damage your mechanical strength. Then, nanosilica, composed of SiO2 nanoparticles, can be a strategy to improve some properties, enabling the incorporation of these aggregates in higher levels and even the use of wastes. Therefore, it was necessary to perform a preliminary study with 6 conventional mortars; followed by an experimental study with 18 lightweight mortars that used expanded clay (AE), sawdust waste (PS) and expanded polystyrene (EPS) as aggregates; finally, the 5 best compositions were choose for the sound absorption test. The results indicate that use of nanosilica can contribute to a greater packing of the grains in the mortars and promote the formation of additional hydrated calcium silicate (C-S-H), it was identified through the results of fresh density, air incorporated content, the bulk density and the thermodifferential (ATD) and thermogravimetric (TG) curves. Nanosilica also contributed to the reduction in capillary absorption and, consequently, in the capillarity coefficient. Furthermore, the use of 3% nS increased the tensile flexural strength and compress strength by at least 88% and 158%, respectively. Therefore, the sound absorption of these composites was harmed, being obtained through the test with an impedance tube, whose weighted sound absorption coefficient did not exceed 0.04. Thus, these lightweight aggregates, although of the lightness, did not contribute to the sound absorption, in view of the pores were filled with SiO2 nanoparticles, leaving the composites dense. Simultaneously, nanosilica contributed to improve to mechanical strength, enabling the use of these lightweight aggregates at higher levels, including it's allowing for the reuse of waste and contributing to sustainability.

 

COMMITTEE MEMBERS:
Externo à Instituição - ALBERTO CASADO LORDSLEEM JÚNIOR - UPE
Externa à Instituição - ANA CECILIA VIEIRA DA NOBREGA
Presidente - 1152919 - ARNALDO MANOEL PEREIRA CARNEIRO
Externo ao Programa - 1179576 - JOSE JEFERSON DO REGO SILVA - nullExterna à Instituição - MARCO ANTONIO SILVA PINHEIRO - UFSM