Abstract

The reintegration of waste into the production chain represents a sustainable strategy to reduce environmental impact while promoting circular economy principles. This study investigates the development of eco-efficient gypsum-based composites formulated with commercial and recycled gypsum, polyvinyl acetate (PVA) emulsions, and chemically treated short green coconut fibers, aiming to assess their printability potential and suitability for additive manufacturing in construction. Composites were characterized through physical, mechanical, and microstructural analyses. The addition of PVA improved workability, extended setting time, and reduced porosity, while fiber pretreatment enhanced interfacial adhesion and tensile performance. XRD, FTIR, and TGA-DTA confirmed modifications in crystallinity, bonding, and thermal stability due to the combined action of PVA and fibers. Compared to the recycled gypsum reference (RG), the optimized composite (R50C50P5F10) exhibited a 69.1% reduction in sorptivity, a 27.9% increase in flexural tensile strength, and a 15.1% increase in compressive strength, while maintaining moderate surface hardness (55–80 Shore C). The results demonstrate the technical feasibility and environmental relevance of these PVA- and fiber-modified gypsum composites as precursors for extrusion-based 3D printing and prefabricated building components, contributing to the advancement of sustainable and resource-efficient construction materials.

Keywords: 3D printing. Recycled gypsum. Coconut fiber. PVA emulsion. Sustainable construction materials. Additive manufacturing

Biography

Sandra Cunha Gonçalves is a Civil Engineer and holds a Ph.D. in Biosystems from the Federal University of Southern Bahia (UFSB). She is a professor at the Federal Institute of Bahia (IFBA), Brazil, and a member of NEEDI – Núcleo de Estudos em Edificações e Infraestrutura (Center for Studies in Buildings and Infrastructure). Her research focuses on sustainable construction materials, emphasizing the reuse of industrial and agro-based residues to develop eco-efficient gypsum composites reinforced with natural fibers and polymer emulsions. She leads projects on Life Cycle Assessment (LCA) and mentors young researchers in sustainable innovation and circular economy strategies.