Isothermal calorimetry in binary geopolymers from construction and demolition waste
DOI:
https://doi.org/10.46421/entac.v20i1.6150Keywords:
Isothermal calorimetry, Ceramic materials, Blast furnace slag, Alkaline activatorAbstract
In this study, thermodynamic interactions and phase formation in geopolymeric systems composed of construction and demolition waste, and also blast furnace slag and metakaolin as complementary materials, were investigated. For this purpose, isothermal calorimetry was used, a technique that measures energy variations in a system at constant temperature. The construction and demolition waste used was cement and bricks, in addition to metakaolin and blast furnace slag. Different mixtures of these materials were prepared and subjected to tests lasting 168 hours, maintaining a constant temperature of 23ºC. The alkaline activator used was sodium hydroxide (NaOH). Through the calorimetry performed, it was possible to observe exothermic reactions in most mixtures. In other cases, significant energy decays were observed, indicating endothermic reactions. These energy variations directly affect the way in which the reactions occur and the properties of the resulting materials. Throughout the study, it was observed that granulated blast furnace slag obtained better energy potential, due to its chemical composition with adequate levels of aluminosilicates and CaO. In general, isothermal calorimetry proved to be an effective tool for studying thermodynamic interactions in systems composed of construction and demolition waste.
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