Banca de DEFESA: SANDRA CUNHA GONÇALVES

Study of the behavior of recycled gypsum added with PVA emulsion and treated short green coconut fiber

PVA emulsion; green coconut fiber; plasterboard; waste

Studies show that in recent years, there has been a significant increase in the global plasterboard market; The main problem, linked to the increasing use of this product, is the need to adequately dispose of the waste generated. One of the alternatives is the recycling of waste in the material's own production chain, aiming to meet the conditions of technical feasibility and the new needs of the sector, to promote economic growth integrated with social and environmental needs. Another attractive issue is the use of fibers from agricultural waste, such as green coconut shells, not only from an economic point of view, but also from an environmental point of view. Several studies indicate that composites produced with plant fibers have relevant advantages for engineering. In this sense, the objective of this work was to produce, analyze and evaluate composites based on recycled gypsum, added with PVA emulsion and short green coconut fiber, previously treated with an alkaline solution. This study was divided into 4 stages: 1) production and characterization of recycled gypsum; 2) analysis of the plaster matrix added with different PVA emulsion contents; 3) analysis of the gypsum matrix reinforced with different contents of treated short green coconut fiber; 4) Study of the behavior of the composite formed by a gypsum matrix added with 5% PVA emulsion and different levels of treated green short coconut fiber. It was found that the incorporation of PVA emulsion and treated green coconut fiber improved the physical properties of the material in relation to the reference sample, reducing the hygroscopicity of the composite, as the water absorption coefficient decreased by up to 69, 1%; The flexural tensile strength, compressive strength and surface hardness gradually increased, reaching an increase of up to 27.9%, 15.1% and 5.8%, respectively. Finally, it was concluded that the composite proposed in this study has potential and technical feasibility to be used in civil construction, as it met the minimum regulatory parameters.