Banca de DEFESA: NATHÁLIA LINS GONZAGA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NATHÁLIA LINS GONZAGA
DATE: 15/07/2022
TIME: 09:00
LOCAL: Pos Graduação Engenharia Civil
TITLE:

Develop of an Accelerated Method for Evaluating the Pozzolanicity of Supplementary Cementitious Materials Based in NBR 5751

KEY WORDS:

Pozzolanic Activity. NBR 5751:2015. Supplementary Cementitious Materials

PAGES: 104
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The cement industry has a major impact on CO2 emissions in the world. Among the viable strategies to reduce these emissions, there is the replacement of clinker with supplementary cementitious materials (SCM), which, in addition to environmental gains, also contributes to considerable improvements in the properties of concrete and mortar. Added to this, the potential decline in supplies of the most used SCM has generated interest in using unconventional pozzolans. In this context, establishing the pozzolanic reactivity of these new materials quickly and efficiently is an essential need so that they can be incorporated into the industry. Therefore, this work aimed to develop an accelerated method for evaluating the pozzolanicity of supplementary cementitious materials based on changes in NBR 5751:2015. The modifications took into account the fixing of the water/binder ratio (0.65), the use of direct thermal curing at 50°C, and until testing ages of 1 day (expedited method) or 3 days (accelerated method). The Farazdaghi-Harris statistical model was used to define the new minimum pozzolanic activity index (PAI). In the end, 10 SCM were tested according to the proposed methodology. The results were compared with NBR 5751:2015 and 5752:2014. Direct thermal curing at 50°C made it possible to classify the materials into inert/pozzolanic materials at 3 days of age in a practical, fast way. However, using the new methodology with 1 day of age proved to be viable in evaluating the pozzolanic character of high performance pozzolans, as in the case of metakaolin and silica fume. In order to be viable to predict the pozzolanic activity of the other materials, more studies need to be developed.

BANKING MEMBERS:
Presidente - 1670637 - ANTONIO ACACIO DE MELO NETO
Externo à Instituição - GUILHERME CHAGAS CORDEIRO - UENF
Externo à Instituição - JUAREZ HOPPE FILHO
Externa à Instituição - KAROLINE ALVES DE MELO MORAES - UFAL