Estudo da influência de aditivo orgânico à base de cacto cereus jamacaru (mandacaru) nas propriedades de argamassas de cimento portland

Abstract

In view of the environmentally costly processes, the civil construction industry is driven by a constant need to optimize its stages. A recurring desire concerns innovation in the inputs used, as well as the application of materials with a natural bias, especially in those already consolidated. In this sense, repeated studies seek to understand the behavior of cementitious materials with the application of plant components, among them is the use of cactus as a way to optimize the properties of the material. The present work analyzes the effects of the organic powder additive based on the Cereus Jamacaru (Mandacaru) cactus, obtained by the spray drying method, on the properties of Portland cement pastes and mortars. In the fresh state, the results indicate, for all the analyzed mix, that the additive acts as a strong retarder of the setting time, increasing the hardening time of the pastes, in up to 1402.8% for 2% of addition in relation to the reference trace. In addition, as a trend, it is observed, in the hardened state, that the increment of the powder causes a reduction in the capacity of absorption of water by capillarity in the samples with additives, in up 74.6% (0.5% addition), as well as a tendency to decrease the compressive strength, the highest values are observed for the reference mix R (0% addition) with 35.4 MPa and the mix D (0.1% addition) with 33, 7 MPa. Finally, from the study of the microstructure of the additive, as well as the various studies found in the literature, the reasons for this behavior are sought.