Banca de QUALIFICAÇÃO: JOSÉ VINICIUS FIRMINO DANTAS LEITE

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JOSÉ VINICIUS FIRMINO DANTAS LEITE
DATE: 14/11/2025
TIME: 09:00
LOCAL: meet.google.com/tyn-rrpw-dpi
TITLE:

IMPACT OF VOID INDEX ON THERMAL PROPERTIES IN LIGHTWEIGHT MORTARS WITH EXPANDED VERMICULITE

KEY WORDS:

Lightweight Mortars, thermal conductivity, energy consumption, void ratio, and expanded vermiculite

PAGES: 24
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Construção Civil
SPECIALTY: Materiais e Componentes de Construção
SUMMARY:

The increasing demand for energy efficiency in buildings necessitates construction materials with enhanced thermal performance. In this context, the incorporation of light and porous aggregates into cementitious mortars emerges as a highly promising solution. Expanded vermiculite, a lightweight and highly porous silicate, is a standout material, recognized for its ability to confer superior insulating properties. This article presents an experimental investigation aimed at quantifying the impact of an increasing void ratio on the thermal properties of mortars, achieved through the partial and total replacement of conventional aggregate with expanded vermiculite. Test specimens were cast for volumetric mixes of 1:3 and 1:4, utilizing vermiculite substitution rates of 25%, 50%, 75%, and 100%. The samples underwent comprehensive physical and thermal characterization, with thermal conductivity serving as the primary metric for evaluating thermal performance. The results demonstrated a dramatic reduction in thermal conductivity, reaching up to 80% in composites with full aggregate substitution. This improvement was shown to be directly proportional to the increase in the void ratio induced by the vermiculite. Furthermore, the variation in cement content between the mixes did not result in significant changes to the thermal properties, indicating that the porosity of the cementitious matrix is the dominant factor. Microstructural analysis revealed a weak bond between the cement paste and the vermiculite lamellae. Finally, the study established a strong correlation between the thermal conductivity results and the void ratios, validating this relationship model as a more accurate predictor of thermal performance when compared to models based on bulk density.

COMMITTEE MEMBERS:
Presidente - ***.403.354-** - KLEBER CAVALCANTI CABRAL - UFERSA
Externa à Instituição - JANAINA SALUSTIO DA SILVA - UFERSA
Externa à Instituição - RÍSIA AMARAL ARAÚJO - IFRN