2023-06-212023-06-212022-12-09BRANDÃO, Luis Felipe Alencar. Influência da temperatura de síntese do metacaulim para uso em pastas geopoliméricas. Orientador: Marcelo de Souza Picanço. 2022. 81 f. Dissertação (Mestrado em Engenharia Civil ) - Universidade Federal do Pará, Instituto de Tecnologia, Belém, 2022. Disponível em: https://repositorio.ufpa.br/jspui/handle/2011/15728. Acesso em:.https://repositorio.ufpa.br/jspui/handle/2011/15728Geopolymers are a type of alkali-activated cement, composed of one or more precursors (sources of aluminosilicates), in general metakaolin, and an alkaline activating solution. This type of cement is known to have low carbon emissions and high initial strength gain, besides being able to incorporate several industrial wastes in its structure and also be compatible for the creation of reinforced concrete or not. Therefore, this work aims to study the influence of kaolin processing temperature for its transformation into metakaolin, in addition to evaluating the best proportion of SiO2/Al2O3 between the range of 3.5, 4 and 4.5 regarding compressive strength. For this purpose, kaolin of commercial origin was used as raw material for the production of the precursor, solutions based on sodium silicate and sodium hydroxide as an alkaline activator. The kaolin was processed at 3 different temperatures (550 °C, 650 °C and 750 °C), originating 3 different precursors, MK- 550, MK-650 and MK-750, respectively. From this, cylindrical specimens were made to evaluate the compressive strength of the geopolymer paste. And by combining with the evaluation of the 3 sio2/Al2O3 contents, 9 analysis points were established. Through diphratometry (XRD), it is possible to notice that there was full amorphization of the kaolin at 750 °C. And when rehearsing the test specimens with cure for 7 days at room temperature, it was found that the best formulation was for SiO2/Al2O3 = 4.0, with 25.2 MPa. After a reduction in the total water content of the system, there was an increase in resistance to 46 MPa at 7 days and when waiting 28 days for the cure of this series, a reduction was noticed to 29 MPa, possibly related to alkali excesses. Further tests show that the water absorption and porosity of the material is 40 % and 48 % respectively. It is concluded that by calcinar kaolin at 750 °C it is possible to produce a precursor for geopolymers of good resistance, being more economical energetically than usual in the literature researched.Acesso AbertoAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/GeopolímeroMetacaulimAtivação AlcalinaCaulimGeopolymerAlkaline ActivationMetakaolinKaolinInfluência da temperatura de síntese do metacaulim para uso em pastas geopoliméricasInfluence of metakaolin synthesis temperature for use in geopolymeric pastesDissertaçãoCNPQ::ENGENHARIAS::ENGENHARIA CIVIL::CONSTRUCAO CIVIL::MATERIAIS E COMPONENTES DE CONSTRUCAOESTRUTURAS E CONSTRUÇÃO CIVILRECURSOS HÍDRICOS E SANEAMENTO AMBIENTALENGENHARIA DE CONSTRUÇÃO CIVILENGENHARIA HÍDRICA