Cinzas da casca do café como material cimentício suplementar

Abstract

The use of non-conventional materials in the construction industry is constantly evolving, primarily due to the high pollution originating from the cement manufacturing process. In this context, there are the Supplementary Cementitious Materials (SCM), such as ash from agroindustrial waste, leftovers from the processing of agricultural crops, which have been studied as a substitute for cement aiming to reduce its consumption. In this concept, the objective of this study is the thermal characterization of cementitious matrices with mass replacement of Portland cement by Coffee Husk Ash (CHA). To achieve this goal, the thermogravimetric technique (TGA) was used for characterization of pastes with water-cement ratio of 0.4 and different levels of mass replacement of cement by CHA. The thermogravimetric curves of the resulting pastes showed that there was a reduction in the formation kinetics and an increase in the number of hydrated products and carbonate materials. The results were inconclusive and, therefore, in view of the widely presented literature trend, it was not possible to prove the feasibility of using CHA as SMC. In this sense, studies with the application of this residue in new lines of research, such as energy generation, soil fertilization as well as alkali-activated matrices describe the diversification and popularization of different and environmentally correct uses of CHA.