The influence of coffee husk ash as a filler addition in mechanical and hydration properties of cement pastes

• DOI: https://doi.org/10.22533/at.ed.1317412415016

• Palavras-chave: .

• Keywords: Agro-industrial ash, filling element, coffee residues, cement hydration

• Abstract: In view of the environmental impacts caused by the construction and agro-industry industries, the aim of this work is to evaluate the potential application of coffee husk ash (CHA) as a filling element in cement pastes. For this purpose, coffee husks and their ashes were characterized. Cement pastes, with a water-to-cement ratio of 0.4, were then produced with different amounts of CHA (5, 10, 15, 20 and 25% BWOC), burned at 600 °C for 3 h, and characterized. The results showed that CHA had a high content of alkalis. A reduction in the amount and kinetics of calcium hydroxide formation was observed in the pastes. In the semiadiabatic calorimetry test, it seems that the increase in CHA content leads to hydration kinetic acceleration and an increase in the cumulative heat for up to 40 hours of hydration, indicating an effective filler effect caused by CHA.