Banca de DEFESA: MARIANA DA PENHA NOVAES
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : MARIANA DA PENHA NOVAES
DATE: 29/07/2022
TIME: 14:00
LOCAL: Escola Politécnica - Remotamente - Plataforma Zoom
TITLE:
INFLUENCE OF PHYSICAL CHARACTERISTICS OF MgO AND ADP IN THE FORMATION REACTION AND PHYSICO-MECHANICAL PROPERTIES OF MAGNESIUM PHOSPHATE CEMENT
KEY WORDS:
Magnesium phosphate cement. Granulometry. Specific surface area Magnesia reactivity. Physicochemical properties.
PAGES: 105
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Construção Civil
SPECIALTY: Materiais e Componentes de Construção
SUMMARY:
With the high consumption of non-renewable natural resources and the pollution associated with the manufacture of Portland cement, there is a growing interest in studies on alternative cement formulations, such as magnesium phosphate cement (MPC). Among the outstanding characteristics of this material are the high resistance to initial compression, high adhesion on different surfaces, resistance to aggressive environments, and low density. Its formation reactions take place at room temperature, without the need for treatments with high energy demand, such as conventional ceramics, or even a clinkerization step, such as Portland cement. However, the factors that influence the formation of MPC matrices are not entirely understood, mainly about the physical characteristics (surface area and granulometry) of the two main constituents: magnesium oxide (MgO) and ammonium dihydrogen phosphate (ADP). Thus, this work evaluated the influence of the surface area and granulometry of MgO and ADP on the formation reactions and mechanical properties of MPC. For this, MPC pastes were produced from the combination of MgO and ADP samples with different granulometries and surface areas (ASBET), two water contents, and three Mg/P ratios. Such parameters were presented as factors capable of influencing the MPC matrix formation reactions in the matrix hardening process. MgO particles with higher ASBET led to an increase in the amount of accumulated heat. The water content proved to be relevant, as it affects the dissolution of the reagents, the supersaturation conditions, and the pH of the mixture, in the formation of struvite. The porosity of the matrix varies mainly as a function of Mg/P but is also affected by the ASBET of MgO. The pastes prepared with Mg/P higher than the stoichiometric showed higher mechanical strength, however, the presence of the more reactive MgO may favor the gain in strength of the pastes prepared with the stoichiometric dash.
BANKING MEMBERS:
Presidente - 1779028 - DANIEL VERAS RIBEIRO
Interno - 2137887 - CLEBER MARCOS RIBEIRO DIAS
Interno - 2315713 - MARCELO STROZI CILLA
Interno - 549.925.915-15 - PAULO ROBERTO LOPES LIMA - UEFS
Externo à Instituição - MÁRCIO RAYMUNDO MORELLI - UFSCAR